Here’s the solution to the sliding coil deteriorated bushing problem on the National NC-101X shortwave receiver. Unlike that other National products with “plug in” coils, like the HRO, the early NC-100 series use a “catacomb” coil assembly that slides inside the chassis to switch bands. A very ingenious design, and it works very well..for 80 years or so, and then the plastic bushings deteriorate from age and use.
The chances of finding new old stock bushings is slim to none, and even if they were available, they’d be just as deteriorated as the ones inside my receiver.
The solution, order a 1/2” to 9/16” bronze bushing from McMaster Carr, machine it down so the outside diameter is .512 inch, press in place using Loctite to retain, ream the ID so the shaft slides through the bushings freely.
I’d like to thank Marc KA2QFX for his very gracious and kind skills in the machine shop, machining the new bushings to fit properly into the sliding coil form.
After two long months, I can finally see the end of the NC-101 project in sight.
National NC-101X Project – Update
Fabricating a new band indicator became a necessity since spare parts for a 80 year old radio are just not something you can find at your local Radio Shack, if you can even find a Radio Shack.
So the old sheet metal, aluminum actually, band indicator, which provides a white dot in each of the band windows as the coil rack moves, was literally falling apart. Given the flimsy nature of the failed unit, I almost wondered if someone made this one.
So, one of the final steps on this project, now that the bushings are installed in the moving coil housing, was to fix or fabricate a new band indicator.
A trip to my local hardware store yielded me some nice 22ga sheet metal to start the project. Thin enough to work with on the bench with simple hand tools, yet rigid enough to last another 80 years. To get the correct form, I straightened the old one out, and used it as a template for the new replacement, scribing around it.
Carefully I trimmed it out, and then used a file for the final shape and deburring. Several coats of white Krylon did the trick.
Better than it was before, better, stronger and faster.
This is the letter that started the entire “Rotten” series in QST, written by “The Old Man” himself, not other than Hiram Percy Maxim.
By “The Old Man”
This QRM business is getting my Nanny. Here it is midnight, and this msg. from a fellow whose girl has not had a letter from him for a full twenty-four hours, is still stalled. I have smoked myself into a state of funk, the floor is covered with burnt matches, I am losing a perfectly good temper, and there is no sign that this will not continue all night long. How long do these radio bugs sit up at night any way? Right now, as I write, there is that old gink 2AGJ up in New York State fluttering along with that bird –in-the-cage spark of his, 8YO is yelling his darned head off for somebody over on the Pacific Coast, apparently, 8NH is still trying her best to be ladylike in spite of a full hour of trouble, old 8AEZ is booming out QSA but QRM bad CUL, 9PC is trying to do something to 5BV, I distinctly heard 4DI say a bad word, and to the best of my knowledge and belief, no one has got anywhere.
What are we going to do about this business? It used to be that we were perfectly satisfied to listen to SLI and once in a while on Saturday night when we could stay up late, we would listen to Arlington send time. When heard some commercial say QRM, we had to look it up on the chart to see what it meant. Later, we began talking to the fellow over on the other side of town and then was born amateur QRM. Sometimes, the “little boy with the spark coil,” (the latter is all right, but dog gone the hide of the former) would try to call us at the same time, and we used to think we were in trouble. Still later we used to think we were bothered when we were in the middle of a “conversation” with a fellow in the next town, and some whop would butt in. It about this era that we began to organize Radio Clubs, with high faluting ambitions about “promoting radio communications and controlling interference.”
But when we have a fellow who has not written to his girl for a full twenty-four hours, and who positively must get the msg. to her over in Illinois, it becomes a serious matter to have some one else getting gay with the ether, especially when the later had no conception of the existence of the word “brevity.” One thing I will say, and that is that good old 8AEZ is brief. His spark may drown out every-body in the western hemisphere when he sends, but he is brief. He says what he has to say in a few words in a few signals and he stops. He also does not go in for the long technical discussions about gap speed and condenser construction while forty or fifty others of us are waiting with five or six messages each, many of which have been stuck on the pin a week. Far be it from even me, a real blown-in-the-bottle radio grouch, to find any fault or mention any names, but some of the young gentleman who burn up my valuable time every night and thereby multiply this QRM business, ought to look up in the dictionary the definition of that particular combination of letter indicated by B-R-I-E-F. I could call off a dozen of them right now, and I would if I thought that Editor down east would print them.
The trouble is, the young squirts don’t stop to think. They start out and call somebody somewhere every three minutes. Everybody they hear, they immediately call. If they don’t hear anybody, they send a QST something like this: — QST QST QST QST QST QST QST de 1NUT 1NUT 1NUT 1NUT 1NUT 1NUT 1NUT 1NUT 1NUT. Any station more than fifty miles distant hearing these sigs. please send postal to Willie le Nut, Nutville. Willie repeats each of this msg. three times. Each letter is sent so slowly it puts you to sleep. He uses up just exactly twelve valuable minutes sending out this hogwash, and drives an old timer to the point where he radiates brush discharge from every hair on his head. These fellows ought to be limited to hours between supper time and 8:30, and any one of them slopping over ought to get a letter from every respectable amateur within his range threatening to spank him if he ever transgresses again. I know a certain some one who will put in his bid for election to the office of Chairman of the Committee on Chastisement.
Here is a sample coming in right now. Listen to this slop:– Columbus co 2pp 18co all sigs charles 9vy u no hf a motor little heavier than the racine sorry sorry om qrm qrm pse qta k fish smell rotten yes yes wyd boston how do you get me gap bum bum rubber band qta pwf about motors. (Bad squeaks here. Sick spark coil near at hand. Wheezes terribly.) Want to hear tone like commercial? ark r r r yes ark r r r listen nw.
Here begins ten minutes of the darndest scratching, screeching, groaning, blowing off steam, blubbering that ever mortal ear heard. At its worst it goes on into — — fine fine how do u do it? ark r r r rubber band on vibrator—BANG. My friend with the one k.w. over on the other side of town explodes. He calls an 8 station. When finishes, the scratching reduces. Then we get the long distance QRM again. Cul om sk spfscity bunk allemo bish mela hash breakfast wunkey wunkey lala lala 2asj arm bad qsl 3zw must go to bed now hw hw hw abt abt abt msg msg msg pse pse pse k k k. This is the way my log book this evening looks. It’s enough to raise a blister on a wooden leg.
Here is another sample of qrm slush:–v v v v v v v v v v—————- (Somebody sitting on his key.) v v v v v v v v v linneg se with the wlce sore feet commercial wirlih. Now what in Heaven’s name would you make out this? Is it to the effect that somebody has a line a commercial who is on the warpath for some amateur with sore feet? One cannot be sure of these matters. It might be that it is the commercial who has the sore feet, chasing down some poor amateur around town probably.
Listen to this:– Yes yes jst wyd glucky wait a mt muddy wouff hong bliftsfy monkey motor. We assume from this msg that Glucky is being asked to wait a minute while Blifsky seeks a wouff hong with which to wallop a monkey the next time the latter faces toward the motor. I do not think I know just exactly what a wouff hong is. Probably some piece of apparatus used in the southern states to beat monkeys with.
It is this form of uninteresting “conversation” which clutters up the air with QRM. Of what moment is it to the rest of the world that this fellow Blifsky is going to smear somebody’s monkey with a wouff hong? When anybody relapses into such mental slop as to want to operate with a thing named a “wouff hong”, he ought to keep his trouble to himself and not compel all of us respectable amateurs to listen to his drool. To slaves and slobber a lot of foolish twaddle like this when that poor girl out in Illinois has not had a letter since yesterday, is plain wicked.
Sorry om qrm qrm 9vy few words schlipsh nuzzle his mucket faded undershirt cfrish reptg pain in neck sus gup om cul ark. This is a real relay, evidently. 9VY over in Fort Wayne is mixed up in it in some way. Whose undershirt they are talking about and what schlipshing one over is, I do not know exactly, although I have a rough idea. Whether the signals faded or the undershirt faded, or what was the matter with the sus gup of the neck of the undershirt, I be darned if I know.
Just cast a lingering look at this:– Biirgrmp bru rotary ge ge ugerumf om with my set rettysnitch spitty tone hit in potimus? Now what do you suppose the poor gink was trying to say when unreeled that? You have to guess a lot in wireless, and how would you guess this? Something is wrong with this fellow’s biirgrmph, his rotary also has a bad case of ugerumf and somebody around the place must have spit on his rettysnitch, because his tone was so rotten it hit him on his potimus. Sound bad to me. Why will some people send such personal matter by wireless when the whole country can overhear it. It isn’t decent, and it makes the QRM more rotten than ever, and just think of the way it makes a perfectly good log book appear.
I spent the better part of an hour trying to make out what ailed the poor fellow’s biirgrmpg, but had to give it up while I listened to a child with a spark coil scratch out this at a rate of around three words a minute:– how do s……..e…….? how be …..? how do I cowp ……. cw ….v v v v v v ——————— come in ? ? ?ark After a long wait another trouble maker with a bad cold in his head stumbled back with:– r r r r r r r r r r r r ok ok please ? ? ? ark Another pause followed by the first little demon with:– r r r r r r r r r r qta qta qta pse rat . . . . . . . ve . . . . . . . .? pse ttt . . . . . . . . . . .qta pse repeat ark. These brats kept this up for twenty minutes and they ended up just where they began.
What we ought to do is organize an Anti QRM Association. Then let us elect for Chairman the worst plug-ugly we can find in these U.S.A. Then let us chip in for a little money and hire a clerk with a bad disposition who will write letters threatening the life of everybody whom the members report as causing needless QRM. If anybody gets balky, we will all join together and swear the gink is sending with a decrement greater than two-tenths, and so report to the local Radio Inspector. If the latter does not within twenty-four hours have the boy arrested and sentenced to life imprisonment, we will all band together and find another job for said Radio Inspector. Let us rise, fellow bugs. Rise and crush this octopus which is engulfing and overwhelming us. Eight hours a day and triple time for overtime is death and starvation to our families. Hash for breakfast, rotten smelling fish, and QRM — — — We will have naught of it. Down with the fellow with the scratchy spark coil, down with the fellow who calls three times three, down with the fellow who calls everybody he hears and down down down with that unspeakable skunk who calls somebody and sends a long relay message repeating each word three times when the station to which he is sending is sending something himself.
There by heck, I have that off my chest. Now you there in Illinois, get this call. Let everybody else stand back from now on. I’m tired and sleepy and cross, and I don’t care who I QRM until I get that pin cleared off.
-The Old Man
This was sent when I lived near Buffalo, NY, in the late 1990s. I had just read a story by Bruce Vaughn N5RQ, now a silent key. Bruce has a wonderful story teller, and friend, and an old time radio repairman. If you ever get a chance to read any of his articles or books, you won’t regret it, closest thing to time travel we have these days. One year Bruce surprised me one year with a wonderful wooden coil holder, after I shared the problem of organizing the coils for my National SW-3 receiver. Enjoyed many emails back and forth about old gear. Regretfully never got to visit him before his passing.
– Bruce W1UJR
I read Bruce’s article with rapt awe, for he very accurately diagnosed the disease that I had been suffering from. When I was first licensed in July 1995 I jumped in feet first. It was like turning a child loose in a candy store. I worked every mode known, from packet, to RTTY to satellite. I pulled all nighters to get my WAS, to find that next contact, I was hooked. Oddly however, during the last 6 months I have started to enjoy the hobby less and less, even though I had more and more equipment.
It seemed great to have a radio with DSP this, and LED that, but something was lacking. And there in lies the problem. I has lost the “magic of radio”, willingly surrendered it, and even paid to sell it off, all for the wonder of technology. My enjoyment of radio became inversely proportional the amount of radio gear I owned. Now my QSOs took place with the relative ease of a cell phone call, and the challenge and allure, along with the magic, was gone. Fortunately the cure for this malady was easy, at least for me. It consisted of “culling the herd”.
I decided to sell off every bit of radio gear that I did not use at least once a week. And with the current market for boatanchor gear, that was not as painful as it sounds! I then committed to return to the real roots of radio, and operate only CW and AM. I have had more enjoyment in the last few months, just sitting in the basement listening to my 75A4 and using my 40-year Johnson transmitter, than I ever had in the past 4 years with all the high tech gear.
It was like I had returned home, to my roots, the to magic. The “Magic of Radio” is not something that can be bought, it must be learned. I recall my wonderment as a teenager hanging a piece of wire out the window, and listening to all of these far away places on my DX-160, and it is now like those heady times again. Today, the new amateur is sadly often “sold” radio as two-way intercom with their buddies. CW, naw that’s old fashioned, use FM instead. We have dumbed the hobby down to the lowest common denominator. Obtaining a license is now almost a right, not a privilege. And we wonder why people drop out of the hobby?
The answer is simple, we sold them defective goods, instead of teaching them the magic, and we sold them a free cell phone. The time-honored concepts of elmering, and home brewing are looked upon as archaic, even backward. But now I know the real truth, and it is magic. From here on in I committed to share the magic with every new amateur, and leave the free calls to Ma Bell.
Bruce J. Howes KG2IC
I was 12 when I first received a Radio Shack DX-160 shortwave receiver for Christmas. My father, who worked on road construction at the time, used to bring home large rolls of wire from blasting caps. I used this wire to construct the largest and most bizarre antenna arrays that you can imagine. I had no real input for antenna design, and since the nearest Radio Shack store was over 50 miles away, I had to experiment. I was fortunate that my parents lived in the country, so I had plenty of natural supports. My favorite was an old, gnarled apple tree about 150 feet from the house. The blasting cap wire was not stranded, but solid and did not have much give, it was noted for breaking and becoming chopped up by the lawnmower.
Despite the antenna problems, I did mange to become an avid SWL, and spent many late nights listening to many of the cold war powerhouse stations. You can imagine my parentís chagrin and concern when I received a letter and QSL card from Radio Moscow.
I really wanted to become a ham, but as we lived in the country, well before the days of the Internet, I did not know who to speak with. Then as time went on I discovered girls and cars and my radio interests went by the wayside for nearly 20 years.
I was in my early 30s when my interest turned back to radio, and began to pursue the dream I had 20 years earlier of becoming a ham radio operator. I first licensed in July 1995, and thanks to the efforts of my Elmer W2UJR, became an advanced license holder in August of the same year, and Amateur Extra class in 1999.
My interest in AM radio is not new however, but dates back to my teenage years. My fascination with radio quite early. My first real radio was old RCA console that had been abandoned in the basement. I managed to get this into my room, and with some tinkering get it working. I would wait until my parents were asleep and listen to the all hours of the morning. I especially recall listening to WBZ in Boston. For some reason this AM station fascinated me, for I was amazed that I could get the news and local information for a someplace as far away as Boston, MA. Yes, many late nights were spent listening to Larry Glick and his call in program on WBZ. That was how I first caught the magic of radio!
For more on my story, please check my “Written Word” section.
73 Bruce W1UJR , the artist formerly known as KG2IC
I’m not quite certain of the author of this work, but here is the reply to The Old Man’s (T.O.M.) “Rotten Radio” letter. Purportedly written to one of those he had taken to task, I suspect that the author may have been T.O.M. himself. The style is most clever, with numerous cultural and technical references, the nuances of which many are lost to us today. So sit back and enjoy the wit of the “The Young Squirt”.
– Bruce W1UJR
The First Epistle From The Young Squirt To The Old Man
By the shades of Mike Faraday and Julius-Caesar, Friend Ham, lend me your shell-like ear and let me gently inquire who in tarnashun and thunderashun is the wild galoot from the west who is always hollering “Rotten”? By heck, this bewhiskered old son-of-a-gun has got my horned animal, or to be brief, explicit, and to the point, my goat. For the last five hectic and sufferin’ years all I’ve heard him yell is “Rotten”. Tell him to go take a walk, take a bath or a shave. Perhaps he can take a drink, (if he can get it). Go and see that pretty little show called “Open Your Eyes”; that might help some.
I want to remark with all due sang froid (which is no relation to aperiodic oscillations) that everything about us hams ain’t rotten. Just to prove my brave and bold assertion, I’ll hereby request in a gentle, subdued—that is, in not a too stentorian tone of voice with a chortle of discontent—that this bewhiskered gazebo take an optical slant at the antenna depicted on the July QST’s cover and then peep inside at the works and the jeweled bearings of the station. Does that look rotten to you, you howling old Bullbum? Go hide your aged cranium, old Pessimistic Humbug Arratus.
Listen in on your own part of the world, Skeezicks; hear Mrs. 8NH (as we’ll always know her). Is her spark rotten, is her fist rotten, is the intensity of her signal rotten when we get her down here in New England like the seventeen regiments of Scotch Highlanders full of Gordon Rye? Answer up, you old geezer, before we dance on your old oaken coffin.
And tell me this, Methusalum, what’s rotten about stations like 1HAA and 1AK? You oughter take a trip to 1AK, seat yourself in his leather upholstered operating chair, lean back in bliss and comfort and be lulled to rest by the helluvanote of YN, the whistle of POZ, or the falsetto of LCM. Then throw his Paragon and hear the dope from Willie Smith out in Missouri who is vainly trying to date up his girl using as a means of dating his little half-inch spark coil. Who said “Rotten”? Everything in the game ain’t “rotten”, as I remarked to a fellow fan when Babe Ruth knocked his twenty-seventh homer. Of course you and I are rotten; that’s why our fellerhams fall for this bunk. It’s so darned rotten that they laugh out of sympathy for the authors. No matter about that, I’m all right and the world’s askew and you (OM) are a loud shouting airdale, mud-slinging hashound. Release the man, he is badly lacerated!
I suspect that you have a dark, dismal and damp cellar at your domicile where you are want to congregate down by your waterpipe and where your ground begins. On a broad and massive shelf overhead, I can now, in my mind’s eye, see you reaching up and detaching a large brown bottle with a bulging belly from said shelf. This bottle, as I see it, is inscribed, “Wood Alcohol, for Adults Only”. You put this horrid exhibit to your lips and take a long drag therefrom. Then you gasp for breath. Back with your shoulders, out with your chest. You feel 75 years younger. You feel fine; you’re drunk y’ darnphule. This is the time, I suspect, that you write those rotten, tainted and corrupted stories. I believe, you old scarecrow, you’re too darned mean to speak a good, cheerful word to us young ham; afraid that we’ll ask you to lend us your darned old squeaking Betsy or your poor abused cat. Personally I don’t believe that you’ve got a Betsy; I think it’s a tin Lizzie.
Did you read that stuff in our July issue written by Miss Grammerhausen—femule ham? What was rotten about that? Guess she is a regular guy. Admit it, you crab-walking, slant eyed son of Macaroni.
I sure had to laugh when I read of an old has-been like you trying out impulse excitation. Guess you know more about output indigestion!
Let’s not drop the subject—while we’re at it let’s flay this knocking old mugwump alive. Now, I myself can sit in on my superdreadnaught set and get stuff that ain’t corrupt. By suitably adjusting the deterioration of my filament due to electrionic emission, (hoping that the Ham (F) gets that phrase OK and considers my think-tank is not out of phase) and as the tiny atomic and infinitesimal electrons seek the path of Prohibition, that is to say the straight and narrow, I proceed to adjust my circuits to resonance, not neglecting the tertiary. Here am I up in New England and twitter—twitter comes NSD. I use NSD as I was wont to use a test buzzer in the Palmy Days. I hear NAM say to him, “O, NSD, O NSD why don’t you set old Ireland free?” Then I know that my antenna is still up and that there’s considerable push to my main spring. So I bend my well moulded head to my work and my youthful countenance (whatever that is) light up with a beatific and a 100KW smile. Hope that all hands will excuse my poetic language. I gotta compete with old Jingle-Jazz. Now my gear is adjusted, so stand from under. I cut her down to 200 meters. In through the window comes 1AW—also that bird Runyon—a guy out in Oak Park, Illinois, whispers in my ear, and Mrs. 8NH flirts with me—a married man. I glow with pride because this ain’t so bad for home made stuff. I try to spit on my female pussy in my zeal, for you see I’m not about to be outdone by old Tom Longwhiskers. I miss pussy and spit in the baby’s ear. Do you call that rotten, Old Drybones? I’ll say it’s gud work—it denotes perfect resonance and unerring aim.
Get some Omega Oil and douse your withered shinbones, Old Timer; then maybe you can get down on your creaking knees and thank the Lord that you’re alive and that you can still hear the lusty roar of the Ham around the corner.
On the level, I’ll bet that you were one of those gazaboes who, in the year 1910 or thereabouts, made the ether squirm to the tune of your decrement. I can see you now, smoking your old black pipe, a green shade pulled over your watery eyes—gazing into vacancy and pounding the devil out of one of Turnsback’s keys. On the tail end of the key you have a tick tacking spark coil operated through an App’s hammer. You still have the hammer, I’m sure. Down goes the key and up goes some poor old commercial station—another good electrolytic gone wrong. You pound on in blissful ignorance and the London Constabulary arrests a man for stealing a loaf of bread.
I sure hope, through, that I can see you down in New York some time. We’ll go Hellpoppin’ together. We must take in a good show, guzzle a little moonshine together, accompanied by the Edison Military Band and the office force of QST.
Come out of your hop, Old Beezlebub, or I’ll put Sheer-luck Holmes on your tail, and he’ll have Watson with him.
Born May 27, 1924, John enjoyed a very full life, as member of the US Army during the occupation of Japan, as a petroleum geologist, traveling throughout the work, as a private pilot who had owned several plans over his lifetime – holding an instrument rating, a most skilled gunsmith and nationally ranked pistol champion, and finally as a ham, with a life long interest and love of radio. It is in the radio context that many of us many have encountered John, and his creations. He was both well known and very well regarded with the vintage radio community, perhaps best remembered for his wonderful home-brew rigs, often built on cherry wood.
He was also an amazingly generous man, happy to answer any technical question, and frequently giving out gear to others, with the only request that they use it on the air. I was recipient of John’s kindness, with the gift of the W2ER rig, a transmitter that John built some years back for Marshall W2ER SK.
I had the privilege of finishing up the Linc Cundell Contest report for John during his illness. While reviewing the logs, it became quite clear how well regarded he was, almost every log entry included a personal letter or card wishing John the best, and thanking him for
73 Bruce W1UJR
This was written by Tim, W1GIG. (Thanks Tim!):
John passed away on March 18, 2008. It was 11 years ago that Bruce Kelly asked John to take over the Amateur Radio column in the OTB as Bruce himself was winding down. John was a man of many talents and had a most interesting life. Because he was always so busy helping others, he rarely took time to talk about himself, so I am going to take this opportunity to tell you a bit more about him.
John was born in Guatemala of American parents where his father worked for United Fruit Company (think bananas). At an early age, his father died of malaria and his mother moved the family back to New England. He also lived with an Aunt and later with his much older brother, an airline pilot, who lived on Long Island. As a teenager John discovered radio and his brother bought him a $5.00 two tube regenerative radio kit to build. John built the kit, but it was another 6 months before he got another kit for the power supply. With the help of a ham who lived nearby, he got the radio working which opened up a whole new world for him. John was in High School when his brother went with him into NYC to test for a ham license at the FCC Field Office. For the next couple of years he was active on 40 M. CW using the regen receiver and a Hartley oscillator.
At this point, WW II got in the way. John enlisted in the Army and was trained in radio repair, shipped off to New Guinea, and assigned to be a telephone lineman. The Army moved John steadily North to the Philippines and then to Japan where he was finally sent back to the States for discharge. John enrolled at the University of New Hampshire where he discovered his love of geology. He liked it so much he went on to get a Masters at the University of Nebraska and several years later, a Doctorate also from the University of Nebraska. He continued to work for Chevron exploring for oil in Africa, Madagascar, Spain, Denmark and many other countries including the US.
While he was in college, John remembered his love of radio, but unfortunately his ham license had expired, so he went back in 1954 to test again receiving the call W1FPZ which he held ever since. Later, he tested for his ham license in Madagascar (in French) and in Uruguay (in Spanish). Not many of us have tested for our licenses in three languages! While he was in Madagascar he built many of the transmitters that are still in use at his home. He even wound his own power and filament transformers to get the voltages he wanted.
John also discovered that he was an excellent pistol marksman, but that his results could be substantially improved by reworking the guns themselves, so he taught himself to be a gunsmith. His skills at woodworking, carving, machining, precision casting of bullets and loading target shells were such that this became a major hobby business for him which he pursued right up to recent months.
John was a survivor. While in the Army he survived a major brush with a 3,300 volt power line and later a plane crash while in Africa. Since small planes were the only way for John to get to his job sites, he decided that he’d rather trust his own skills as a pilot than relyon the brush pilots that the oil company had hired. Back in the States, recuperating from his injuries, he got a private pilot’s license, then went on to a multi-engine commercial license with full instrument ratings. Just before he retired, he was working out of Denver and flying his own twin engine Queen Air to Maine to work on his retirement home. He even flew from Maine to the AWA conference one year picking up MarshallEtter, W2ER from Long Island on the way.
Preparing for retirement, John and his wife Liz doubled the size of their new home in Maine. As part of the project, John wanted reliable ham communications with his friends around the world. Limited by normal power regulations, he decided to build a BIG antenna. His final choice was a horizontal V beam aimed at the Southeast. The beam legs were 1,100 feet long and supported on three 100 foot towers. Looking for wire strong enough to span the distance he ran across an ad for #6 phosphor bronze wire run by Marshall, W2ER who had salvaged the wire when he was closing the RCA site at Rocky Point. The two men became fast friends and co-conspirators. Marshall provided quality parts left over from RCA and John, using his metal and woodworking skills, customized the parts to suit his projects. The result was a long series of radio projects that he gave to friends with the caveat that they were required to use them on the air in AWA events.
John always had a fascination with the products of Jerry Gross of NYC. He built a Gross replica transmitter for Marshall who used it for many years. Parker Heinemann, W1YG found an original Gross and had John restore it along with the receiver, station monitor and antenna tuner. They set up an entry in the 1991 AWA contest that exactly duplicated a Gross add from the 30’s and took first place. After the conference, John got a call from Bill Orr who offered John his Gross if John would restore it. That transmitter is part of John’s home station.
Not satisfied with the Hartley oscillator, John discovered that if he used the Colpitts circuit with a split stator condenser and grounded rotor, he could eliminate the hand capacity effect. One of his last projects was to set up the tuned circuit for me and share several of his other construction secrets. The circuit is rock stable on 40 meters.
Thanks for the opportunity to fill you in on some of the less well known aspects of John’s life. It was an honor to know him and he will be missed by all.
I removed the sliding coil assembly, often called a “catacomb coil” for cleaning and service. Needed it too, 80 some years of dirt, and old grease build up make it a mess.
Removed the coil sets, used a sharpie to id the location with small dots, and threw the aluminum housings, top and buttom, in the dishwasher. Worked like a charm, the reassembled, and carefully cleaned each coil set, and wiped down the pins with Deoxit. Lubricated the shaft that it slides on, and cleaned on the old nasty hardened grease out of the gear drive on the front. Tomorrow I have to paint the white band indicating tab, and reassembly. Or, I may go after the recap work first, the old wax paper caps aren’t too bad with the catacomb coil set out. Only a total of 21, should be an afternoon’s worth of work.
A Work of Art – “A Collins Time Capsule Found”
By Bruce J. Howes W1UJR
October 2, 2006, just after 9:30PM EST, on a small peninsula on the Maine coast, a Collins 30K-1 amateur transmitter, serial number 32, returned to life after a 48-year hiatus.
|RF Deck and 4-125 tube||Modulator Deck and 75th tubes|
This was no simple resurrection, but the culmination of a long journey that started over half a century ago. The journey began in 1947 when serial number 32 left the Collins factory at Cedar Rapids, Iowa, and traveled to the station of Walter Jahries, W7MGA, in Salt Lake City, Utah. It saw service at W7MGA until sometime in the late 1950s. After the passing of W7MGA the unit was put into storage. In 1991 it traveled westward to Los Gatos, California and the home of Peter K6DGH.
Peter, busy with other projects and his Hallicraters HT-4 station, never got around to unpacking the transmitter and getting it on the air. So there it sat, in heated storage, for 15 years, until September 2006, when it headed for the east coast and to my home at Woolwich, Maine, some 59 years after it first rolled off the factory floor.
But it was not just the transmitter that survived the half-century of storage and travel, amazingly the complete station, sans antenna, survived intact! For included in the package was the matching Collins 75A-1 receiver, Collins 270G-1 speaker, Collins 310A exciter to the drive the big 30K-1, W7MGA’s manuals, extensive spare parts, a homebrew coil holder and Shure microphone. In other words, the complete 1940’s era station of W7MGA had been transported through time and space to arrive here, the coastal station of W1UJR.
A Little History
A few words about the 30K series. I have been a Collins fan since I was first licensed in the 1990s, but really fell in love with the 30K when I visited the home, perhaps more appropriately, the radio museum, of Todd KA1KAQ. Todd had the commercial version of the 30K-1, known as a 30K-5, and I was privileged to work on it for him last December. Very similar in design, the 30K-4 and 5 are commercial models offering two discreet tank circuits for rapid frequency changes but lack the bandswitching arrangement of the 30K-1.
The 30K series was designed by Collins engineer Warren Bruene in 1945 and was first offered for sale the following year. It was, in some way, a “Hail Mary Pass” for Collins as the war contacts were drying up, and yet amateur radio operation was still banned during wartime. Collins forecast a pent up demand from the return of GIs from the war, and with the elimination of the wartime ban on amateur operation, hoped the 30K would fill the gap. Sales were somewhat limited as the 1946 cost of the 30K-1 transmitter and 310A exciter was $1450, the equivalent to approximately $15,000 in today’s dollars. According to Jay Miller’s, KK5IM, excellent publication, “The Pocket Guide to Collins Amateur Radio Equipment 1946-1980”, less than 100 of the 30K-1 are known to have been built, and few survive today, making serial number 32 a rare bird indeed.
|June 1946 QST Ad||May 1947 QST Ad|
Visually, the 30K transmitter series are most impressive to behold, housed in a cabinet 5 ½ feet tall, finished in black wrinkle paint, and weighing over 350lbs, this is a big transmitter! The design of the unit is pure art deco; vertical and horizontal chrome accent strips, a large window for viewing the 4-125 final tube, and a most impressive meter panel at the top of the cabinet, also housed behind glass. Looking every inch a serious transmitter, the 30K-1 is of robust construction along the lines of commercial broadcast gear. Emission modes are CW and Fone (AM), with the plate input power given as 500 watts on CW, and 375 watts on AM. The 30K-1 offered coverage from 80 to 10 meters using two plug-in output coils. With a tube compliment of 11 tubes in the transmitter, and 10 tubes in the 310A exciter, the 30K station as much a delight to operate, as it is to look at.
Always Practice Safe Shipping
As safe movement of even a small receiver coast to coast is often a daunting task, I wanted to take extra care to make certain that this station, entrusted to me, made the trip intact. I won’t enter the debate of who is better/worse, UPS or FedEx; suffice to say that I have developed two simple rules for safe shipping. First, pack the unit as a box within a box; peanuts are near useless, use bubble wrap and foam. Second rule, the less time in transit, the less change for damage, Overnight or at the very least, 2nd Day Air Ship everything fragile.
Fortunately Peter had considerable experience packing and shipping vintage electronic gear, so the process was quite straightforward. Careful packing, with a minimum time in transit, it’s the key to the shipping of fragile electronics. Brian, at JDM Packing in Sunnyvale, CA, did an outstanding job of packing up the 75A-1 receiver and the 310A exciter. The method was surprisingly simple, a large box, then a layer of dense foam, then another box, and again dense foam, followed by the object to be shipped, which was bubble wrapped. I utilized my commercial UPS account to have all the critical items sent overnight to minimize exposure time. All items thankfully arrived without damage, and I saved the packing for future use.
|Dense foam to protect the knobs and face||The box within a box concept|
With the easy items out of the way, now came the real challenge, how to ship the 5 ½ foot tall transmitter across the country without any damage. Wisely, Peter had already removed the heavy plate transformer and shipped that separately. So with the nearly 75 lbs transformer out of the way, Peter once again called on Brian for assistance. Brian built a large enclosure, again with the dense foam packing, placed the transmitter on its side and then banded the entire unit, all 5 feet of it, to a wooden pallet. Cost estimates were obtained for surface (truck) transport and 2nd day airfreight. Surprisingly the cost differential was minimal, and BAX handled the airfreight duties, delivering the package safely to the door of my office just two days after it left California. My employees, used to seeing various small radio items trickle in, were astonished at the size of this large coffin sized package. I informed them that it contained the remains of a deceased family member, and required special handling! Once it was safely unloaded at my workshop, I let fly that it was in fact “yet another radio”, which brought forth a profound sigh of relief.
|The 30K-1 “Coffin”||With the packing removed|
Whenever I purchase vintage amateur gear, I like to know whom the identity of the previous owner, or builder, and document the construction, use and ownership of the item. The museum people call this “provenance” and use it to establish the authenticity of an item. For my purposes I find this information gives me a greater appreciation of, and respect for, the handiwork of the previous owner. It can also be helpful for restoration purposes, knowing what period of components to use in a rebuild, or even in designing the station configuration.
Fortunately Peter remembered the name and callsign of the previous owner, so with the Internet close at hand, it was a simple matter to quickly track down his next of kin. I sent a tentative email off to W7MGA’s son, Conrad, who was most helpful in filling in the details and history of the station. Conrad, shares the history of the station.
“That is interesting about your having the old 30K station. Yes, it belonged to my Father, W7MGA (born in Chicago in 1895). I think he probably bought it from Henry Radio in Kansas City, probably in 1947 as he returned from Hawaii in 1946. He was the district manager for S.H. Kress Company in Hawaii and the store manager for the Honolulu store. He retired over there I think in 1946 and moved back to Salt Lake, where he lived before being transferred to Honolulu in 1936.
The way he got into ham radio is when we lived in Honolulu, my brother was going to university here in Salt Lake, and he ran into a fellow by the name of Malc Majors. Malc was a ham there (W0OJI) and set up schedules between Hawaii and Salt Lake to talk with my brother. When we returned to Salt Lake he got his ticket probably about 1947, and purchased the Collins equipment.
I was in school then and remember his having people up to the house all times of the day and night to have schedules with servicemen in the South Pacific. He was using 4-element beam for 10 meters and 3-element beam for 20 meters. It was home made and sat on top of a 44 ft. Vesto tower. The skip was open then and I think he made most of his contacts on 10 meters. I think 10 meters was open then and the skip was good in the early evenings and people were over to the house almost every day. He did a lot of hamming on 10 and 20, spending most of his time in the shack He sort of lost interest in hamming in the late ‘50s and the Collins sat in his shack for quite a while. When he passed away, I got it and it sat in my basement for several years not being used. I was interested in RTTY when I had Collins here, and used Kenwood Twins when I was on the air, so I never used the Collins or Henry at all.
You should get Dad’s QSL card. That is a shot of a 45’ Vesto (windmill) tower that Malc was selling back in Kansas City. It was taken from the center inside of the base looking straight up. He built the beam himself.”
|W7MGA’s QSL Card|
The Process Begins
As noted, this time capsule has been unused since the late 1950s, so the task of careful removal of half a century’s worth of accumulated dust and dirt is no simple matter. It calls for both a through and methodical approach, while preserving the integrity of the unit to be restored. This 1940s vintage Collins 30K-1 has not traveled through time and space only to be damaged at my hands. So I proceeded with the utmost care. Each part, nut, bolt, screw that I removed was placed in labeled sandwich bags for later cleaning and evaluation. I carefully photographed and noted the location of each wire disconnected so it could be put back into its proper place (digital cameras are excellent for this purpose).
There are two basic schools of thought on restorations. The first school takes the approach to make every nut and bolt shine, to polish IF cans and other sheet metal to a mirror finish. To in short, make the unit more of a piece of art, eye candy if you will, than the purpose it was designed for. An apt analogy for this school of thought might be a heavily chromed and tricked out 1957 Chevy at an auto-show vs. the daily driver. Over the years my approach to restoration has moderated, as you will note below. My current theory behind most of my restorations, and this unit is no exception, is to return the item to be restored to the condition in which it left the factory. This means the use of the same style hardware, like kind and type of wiring, and same finish, if refinishing is needed.
I’ve moderated on the depth of restoration efforts over the years, accepting the “in-service” look as opposed to the overly done, polished chassis approach. This is no way means that I compromise on my efforts, it simply means that I restore the transmitter to the level which a ham of that era would see the unit. It should look, for all intents and purposes, like it was NOT restored but is simply an in-service unit. In most cases this means keeping intact the original finish, labels, sheet metal finish, etc. Dependent upon the restoration, I do endeavor to remove modifications added over the years, the goal being to return the unit to the standard operating condition.
Nor do I ever really “finish” a restoration. Often I will pull a unit out of service after perhaps six months or years worth of use, and go through it yet again. With older gear, parts will invariably be damaged or missing and often not readily available during the first restoration. So I will employ “field expedient measures”, temporary fixes if you will, to allow the unit to operate, while scouring hamfests and the Internet for the needed part. It is during this second trip to the bench, I find myself carrying out additional cleaning, realignments, and checking component values again. Despite a through “burn-in” effort during its initial visit to my test bench, oftentimes certain components don’t fail until they have some additional time and use. So, in general, my time is spent correcting any overlooked, unsatisfactory items from the first work. I find it often takes 2-3 trips to the bench before I m satisfied that I have the unit ready for another 50 years of service.
So, let’s start with the first part of any amateur radio station, the receiver. The receiver, exciter and plate transformer had arrived first while Peter made preparations to ship the large and more cumbersome transmitter. Restoration work on the W7MGA’s 75A-1 receiver began on Sunday, September 10, 2006.
Restoring the 75A-1
For a receiver which appears to been unused for nearly half a century, this A-1 was in surprisingly good condition. Before I even attempted to fire it up, I did the standard W1UJR clean and restoration. When cleaning an old radio, the first order is to remove the dust, then concentrate on cleaning the chassis and other components. I’ve found it far easier to vacuum or blow said dust off than it is to get it wet and try to wipe it down. So out came the trusty Shop-Vac with the small brush attachment. Always use a brush if possible, it really helps to loosen up the caked dust, much more efficient than using just a nozzle itself.
|Before cleaning||49 years of dust!|
When restoring gear that has been out of service for some time, one must be very careful of the presence of rodent droppings. It’s not much the droppings that are the problem as it is the potential for transmission of the Hantavirus. If you see any droppings at all, always take the safe course and do not create aerosols by blowing with compressed air, or aspirating with a vacuum. The safest method is to don a pair of rubber gloves and a respirator, wet down the droppings with bleach. The remains should then be placed into a trash bag and carefully sealed. Take additional time to thoroughly clean and wet down the chassis to remove any residual remains before going further.
When I start a restoration, I make a quick inventory of items to be replaced, serviced or checked. Once the cleaning is complete I then attend to the electrical items. I realize that some folks feel the electrical should come before the cosmetic work. I find it much simpler, and enjoyable, to service a clean radio as opposed to a dirty one.
Over the years I have tried many cleaning products, with varying success. What I have now settled on, and seems to do a good job, while preserving silk-screened chassis markings, is the commercial version of Windex. Windex, and a number of cloth rags. Cloth is much more durable than my earlier choice, paper towers. Cloth allows you to scrub firmly, and can be even used for a polishing effect on tarnished parts. For really stubborn, or nicotine coated units I resort to the Simple Green product.
A word on black winkle, sometimes called “black crackle” paint. On most black wrinkle paint items I prefer to keep the original finish intact, as today’s paint compounds can not properly duplicate the subtle wrinkling effect of the early lead paints. Originally chosen for its durability, as well as its ability to hid minor sheet metal imperfections, this finish is amazingly forgiving, and most grime can be removed by gentle scrubbing with a nylon tipped bush and Go-Jo hand cleaner (without pumice).
|Everything gets removed||Its the little things that make the difference|
As a rule, I always remove all of the front knobs, inner sheet-metal covers, and trim bezels when doing a restoration. Be very careful with the Bakelite knobs, Windex seems to have a dulling effect on the Bakelite. I clean and then treat Bakelite items with Wurth Cockpit Cleaner. The Wurth product allows the dull shine to return to the knobs while not looking overly glossy.
I also remove all the tubes, clean and test them before reinstalling. As part of the cleaning process I coat the pins with Ciag Deoxit compound. Metal tube shields receive a quick buff with Windex and the cleaning cloth.
|Remove all knobs and sheet metal||It saves time and allows a better job|
Any and all wax paper caps, no matter how new they look, should be replaced. I use the Sprague Orange Drop line of capacitors. While the Orange Drops are perhaps overkill, I know that they will not fail, and the unit, once fully serviced, is good for another 50 years.
Special attention should be paid to the electrolytic capacitors in the power supply. Once the unit is fired up, one can check the audio output for hum, indicating a defective filter cap. Also check the outside can of the electroytics after the unit has been on for 10-15 minutes (be careful with this, some units, like the Heathkit DX-100, have the metal housing of the capacitor above ground potential). It should be at room temp, not overly warm. If the can feels warm then the cap is not doing its job and its time to replace it before it damages the power transformer. Yes, I know the process of “reforming” such caps, but my feeling is that if the cap is bad, it is not to be trusted, and I will replace. Power transformers are certainly more costly, and more difficult to locate than an electrolytic cap. Suppliers like Antique Electronics Supply are an excellent source of replacement caps, even the electrolytic series.
|Looking like a proper radio now||The finished product!|
Surprisingly W7MGA’s 75A-1 powered right up and played like a charm. Just a simple touch up of the alignment was all that was needed to make the unit both look and play like it was fresh from the factory shipping crate!
The Big Box Arrives
Just in time for the weekend, the transmitter arrived on Friday, September 29, 2006. Now the real challenge began, bringing the big 30K-1 back to life. One never knows what to expect with working with old electronics. Was the unit still working when put into storage, was it put aside due to some major component failure, or has some odd and unavailable component given up the ghost in the preceding decades of storage? I always assume the worse, and check for shorted power transformers, or other zorched components prior to any restoration work. Of course, half the battle is understanding WHY the component failed. For example, did the power transformer burn up because of a defective filter capacitor, or did it die on its own accord? Understanding this helps expedite the restoration process, and allows you to do a targeted, rather than shotgun type of repair.
So let’s talk about the Collins 30K-1. I had plenty of time to read up on the transmitter prior to its arrival. Collins always did an outstanding job in their manuals explaining not just the operation, but also the theory behind the unit. Reading a Collins manual, with its excellent photos, schematics and theory of operation, is an education in itself.
A few words about the 30K-1 design. One word that comes right to mind, especially if you are used to other amateur gear of the era, is “robust”! The 30K, although built as an amateur unit, shares many of the design characteristics with its big brother commercial broadcast gear, and is unusually roomy to work on. As mentioned before, the unit is housed in a 5-½ foot cabinet and consists of four separate decks; the high voltage power supply deck, the low voltage power supply deck, the modulator deck, and the RF deck. Power requirements are moderate, 115 VAC at 1350 watts of current. The RF output network, which is mounted by four ceramic standoffs to the front of the cabinet, completes the layout. Like most commercial broadcast transmitters, the heavy iron, in this case the plate transformer, is located on the bottom of the cabinet. Each deck is connected via a terminal strip on the rear panel allowing easy removal for servicing.
Tube replacement and most other standard maintenance items can be carried out with the decks in place. Should deck removal become necessary, say for replacement of a under chassis component, you must remove the four retaining bolts which hold the deck to the support rails. Once these are moved, and the wiring disconnected, the deck slides right out. Be careful during deck removal or installation, its easy to damage the cabinet finish with the deck edges. To prevent this, I use blue painters tape, it leaves no residue, on the cabinet edge and rails. Two or three layers of tape offer plenty of protection against nicks and scratches.
A Tour of the 30K-1
The high voltage deck uses a pair of 866 mercury vacuum rectifier tubes to handle the HV supply duties. The design is both simple and robust, really overbuilt for amateur service. The things to check here are pretty standard with any HV supply; look for arcing to ground, loose connections or damaged insulation. Heavy oil filled caps are used exclusively on this deck, so capacitor failure should not be an issue. I did find a problem with leakage in the 866 filament transformer on my 30K-4 transmitter. Check the obvious, and then bring everything up under low power for testing. In fact, it’s a good practice to leave the filaments on for several hours, just to bake any moisture out of the transformers, before you hit the plate switch.
|HV deck prior to cleaning||HV deck installed after cleaning|
In general the HV and LV wiring insulation used by Collins appears to be very resistant to breakdown, and thankfully both of 30K-1 and 30K-4 units have excellent wiring. Failures of the plate transformer have been reported on the Collins reflector, so be cautious here. The plate transformer is a heavy Thordarson unit, secured to the cabinet base with four 12-24 retaining bolts. Mindful of the mild plate transformer hum on the 30K-4, I did something to try and quiet down this rig. I installed four 1.5 inch diameter rubber washers under the transformer mounting boss. This provides a solid attachment, yet serves to dampen some of the hum of the transformer under full load.
The low voltage supply deck uses a standard line up of 5R4GYs for bias and low voltage rectification. The bias potentiometer for the 75th modulator tubes is located on this deck, you may want to clean and set it to midsection for now. Later, the bias for the modulators should be set to 45 ma. You may want to pay special attention to the filter caps on this deck, given the age of the transmitter, electroytics are used and they may be suspect. Thankfully mine required no attention, just a cosmetic cleaning of the deck itself.
|LV deck prior to cleaning||LV deck after cleaning and testing|
It’s on the modulator deck where things really get interesting. Collins chose the pretty but now rare 75th tubes as modulators. The 75th has a large circular globe, with a nice bright filament, and is really a very attractive tube in operation. Unfortunately Collins did not provide a viewing window for the modulator tubes, so one has to be content with the glow of the 4-125 final. The 75th has now become a somewhat rare tube, thankfully I found multiple sets included with my unit. Some folks have reported success using the more common 100th tubes as replacements, I understand a bias modification is necessary.
|Modulator deck before cleaning||Modulator deck installed after testing|
Electrolytic caps are used on this deck as well, so be certain to check thoroughly both before and after the initial fire up. I did encounter a problem on this deck with the audio gain pot in the speech amplifier circuit. A trip to my junk box produced the requite 500K potentiometer and we were back in business. Be sure to lubricate and clean up any switch shafts and contacts.
The RF deck is perhaps the simplest of all the decks in the unit to clean and service. Removal from the unit is rather straightforward. Remove the front two adjusting knobs, the large air variable capacitor support insulator, plate cap on the 4-125 final tube, and finally unbolt to the two choke leads from the bandswitch. Remove the five wires from the terminal block and you are home free.
While you’re under the deck you might as well remove the two screws that retain the two RF chokes, along with the one screw that grounds the RF chokes to the chassis. With the chokes and the large fixed capacitor removed, cleaning the deck is quite straightforward.
|The RF deck, after removal of parts for cleaning||Underside of RF deck|
Once you have the RF deck on the bench, I advise that you blow off as much loose dust as possible with compressed air. Then use a strong shop vacuum to pull off any reaming dust and dirt. The large fixed capacitor removes quite easier from the deck, just two retaining screws. This capacitor is very difficult to clean when assembled and as any dirt here provides an easy arc over path, its well worth the time to disassemble and thoroughly clean the capacitor plates and hardware. What I like to do with a small chassis, especially if heavily soiled, is to use Simple Green and shop rag to wipe down the deck. Next turn the deck on its side and spray a heavy coating of cleaner on the top and underside. Allow this work its magic for perhaps 5-10 minutes then rise clean with tap water. A quick trip into 200-degree oven for 5-10 minutes does wonders for the final dry cycle. Now you can Q-tip any residual staining or dirt, especially around the terminal block. Allow the chassis to air-dry overnight and its ready for reinstallation.
Collins built a very robust and flexible link coupled output network in the 30K-1, allowing both parallel and series tuning. The lower bands, 80 and 40 are handled with one large plug in coil, while the upper bands use a somewhat smaller coil unit. RF is output through one set of feedthrough insulators mounted on the upper rear of the cabinet. Thinking ahead, Collins design made provision for the use of multiple antennas with the installation of additional feedthroughs and the ability to directly tap off each section of the bandswitch. My unit had apparently sustained some impact during its trip from California, as each of the four porcelain standoffs that mount the network to the inside of the front panel was broken. These standoffs are of the standard tapered design, often found at hamfests; thankfully my junk box yielded four identical spares. My output network was very dirty, and given the complexity of the coils and windings, it was not an easy clean up job. A trip through the dishwasher, at low heat, was in order. The unit emerged looking like new, and I took a few moments to clean and tighten all hardware, and then lubricate shafts and linkages before reinstallation.
|Output network before cleaning||Output network after cleaning|
Before installing the output network, I removed the large meter panel from the upper top of the cabinet. The 30K uses a meter display similar to many broadcast transmitters of its era, behind glass. The meters were fine, requiring only a cosmetic cleaning, but the glass was a filthy. I have yet to find anything that cleans glass better than Windex and newsprint, and soon the meter display was reinstalled and looking like the day it left the factory.
A Few Fixes
W7MGA had fabricated a very clever antenna switching arrangement in my 30K-1. If you look closely at the rear of the bandswitch you will note a black DPDT knife switch mounted on a Lucite disc. By this unit he was able to select multiple antennas for different bands. Desiring to return my unit to stock, it was a simple matter to remove the three screws that secured the switch. I then found the original bandswitch jumpers which Collins had installed at the factory, the previous owner had thoughtfully hung those inside the cabinet on a piece of wire when he installed his antenna switch! So, with the addition of just a few jumper wires from the bandswitch to the porcelain feedthroughs, RF was once again ready to flow.
One thing that I should comment on was the respect that the W7MGA had given the rig. It was obvious to me that he cared for it greatly, carefully building the Lucite antenna switching device, collecting multiples of spare tubes, retention of the Collins manuals and marketing material, even fabricating a black wrinkle finished dolly to move it around. He went so far as to build a wooden base to hold spare tubes, and to construct a classy glass and wood enclosure for the antenna coil used on the higher bands. Unlike much amateur gear we see today, no additional holes, switches, or modifications were found. It was clear to me that Walter had a great respect for this transmitter, and that further inspired me to continue on in his tradition.
With the decks all cleaned, serviced and tested, the final step remained, powering up the unit. I checked and double-checked each connection, making certain that all was well and proper. Preparing for the event, I had both camera and video recording gear on hand and rolling when I throw the filament switch. It was, in a word, a nonevent. No spark, arcs, or blow fuses, it just worked. And so, just after 9:30PM on October 2, 2006, Collins 30K1, serial number 32 returned to life. I joyfully recorded this moment with both still and video cameras, as one would a new child.
4-125 at full glow
|75th modulator tubes|
Then, after just 5 minutes of operation the filaments in the 75th modulator tubes promptly went out. I had intended to just let the filaments run for several hours to dry out the transformers and vaporize the mercury in the 866 rectifier tubes. The apparent filament failure puzzled me, but feeling emotionally and physically exhausted from nearly 12 hours of work, I called it a night and powered down the unit. In my head it knew it could be anything, but in my heart I feared the worse, a failed filament transformer. It was with this in mind that I grabbed the schematic on my exit from the workshop.
After staying up until 1AM that night studying the schematics, I tried again the next day. I plugged in the 30K, gingerly turned on the filament power, and checked the modulator tubes, no joy, no light. It then occurred to me that as the 4-125 and 75th tubes share the same filament transformer, and the 4-125 filament was lit, it must be something in the wiring of the mod deck filaments.
I thought and I pondered, doubled checked my wiring, looked for smoked components under the chassis. I checked the schematic again, and then broke out the toolkit and DVM to check voltages.
Then, suddenly, I heard the voice of Art, yes Art Collins himself, calling to me across time and space (not really, but that sure sounds good!). It occurred to me to turn the FONE/CW switch, and like magic the filaments lit! That switch must have been right on the very edge of the detent and snapped over when I was moved things around while checking out the transmitter last night.
I had noted a problem with the switch while cleaning the mod deck; it was very stiff to turn. I had gently heated it up and applied oil to the shaft, which, after some work, made an improvement. It appears that I must have left the switch not quite on the detent and it snapped over to the CW position, removing filament voltage from the 75th tubes! It was just sheer coincidence that this occurred while testing out the filament supply.
|30K-1 tag, serial number 32||Found inside the RF cover of the 75A-1||75A-1 serial number 61 lives again|
With the filament problem now handled, I turned to the Collins 310A exciter. The unit was in very good condition and it was simply a matter of attaching the 5-wire harness from the 30K to the 310 so the unit could be powered up for testing. The RF cable from the exciter uses one of those old single pin connectors like you would frequently see on transmitters like the Heathkit DX-100.
So, with the exciter properly cabled to the transmitter, it was just a matter of putting the exciter switch into the “SEND” position and check the grid drive. Some tweaking of the input network controls on the 30K produced grid drive, but with a low reading of 7ma in the tune position. Ideal grid drive for the 30K-1 is 12-15 ma, so some work was indicated here. Just to check for output and make certain that the exciter was near frequency, I turned on the 75A-1 receiver. A quick check confirmed that we are operating on or about 3885 kc, not bad for a 50-year-old unit. Still more work was indicated on the exciter before we could properly test the 30K-1 under load.
The Collins 310A, another Warren Bruene design, is like a small transmitter in itself. Using the venerable Collins Permeability Tuned Oscillator, and a pair of 807 tubes, the unit is as robust as the transmitter it is matched with. Servicing the 310A could not be easier. It does not need to be connected to the 30K-1 for service; just a simple line cord to a wall outlet provides all that is needed.
I had a moment of consternation during servicing the 310A which I will relate in the hopes of saving someone else grief. The exciter, which worked fine with the 30K-1 (abet with low output), had no output on the test bench. It was time for a rest break, and after a cup of green tea, and reading the schematic several times I figured out the simple cause. The front panel keying jack is of the shorting type and provides a ground return for the cathode resistor of the 6AG7 tube. When I removed the exciter from the cabinet I had disconnected the keying jack, therefore disabling the operation of the tube. A jumper was quickly fabricated and we were back in business.
During my initial testing I had noted low grid drive on the 30K-1, which translated into low output from the exciter. I removed the exciter bottom cover and quickly found the cause. The 310A uses a series of three ganged air variable caps, driven off the front tuning gear train. The first air variable, which tunes the low oscillator stages, was fine, but the other two air variables were not tracking with the first, owing to a loose coupling. The rear air variable, used to control tracking of the 310A’s output network was not moving, not was the small cap used to turn the input to the first 807 tube. Thankfully it was Collin’s excellent manuals to the rescue again, and after a quick review I understood the problem, and how to correct it. It is a bit of a procedure to get the three air variables tracking properly, but once done it should last for a lone time.
Thoughtfully Collins provides two test points for measuring both the grid input to the 807 and the plate current. By the removal of two jumpers, a milliamp meter can be interested to quickly align the circuits. An excellent design, and one that allowed me to quickly get the 310A back on-line.
Live To Air
Over the next few days I checked various voltages in the transmitter, ran on low power into a dummy load, and was finally ready, a week after its arrival from California, to test it on the air. The maiden voyage of serial number 32 was carried out on October 8, 2006 with KA1KAQ. Both the audio and signal reports were strong, with the D-104 on one end and the balanced feed 160 meter dipole on the other. At the rated Fone plate current, 150 ma, the 4-125 final tube has dull red or cherry glow, and the complete transmitter, which uses no fans – only convection cooling, is remarkably quiet.
Air tests continued on and off during the week until I was satisfied that the unit could be moved back against the wall, and the 75A-1 and 310A be installed permanently into the station. Bill KC2IFR was kind enough to send me a recording of me on the 30K-1, and it was a real pleasure to finally hear myself on the rig.
Operation of the 30K-1 on the air could not be simpler, once you get used to the lack of Push-To-Talk operation. Rather than keying off the microphone handle of the D-104, the 30K-1 is designed to be keyed off the front panel switch of the 310A exciter. One simply places the 310A switch in the CAL position to zero beat the 75A-1 receiver, then in the REC position to listen in, and finally in the SEND to key the 30K-1 and transmit. It does take some getting used to, remembering to turn the switch to go from send to receive, but after some use it becomes quite natural. Provision is even made in the 310A to mute the 75A-1 during transmit.
The 30K-1, with its 250 watts of AM Fone power, is great for those late night QSOs. You know that you have plenty of reserve power to overcome atmospherics, and still provide the static quieting full-bodied AM sound. The stock 30K-1 audio is as Collins intended it, punchy and crisp, not at all objectionable. A limiter, using a 6H6 tube, was engineered into the unit to allow full modulation without distortion; I’ve left this intact. The limiter can be defeated by adjusting the pot, or just removing the 6H6 tube. In the interests of authenticity, I have chosen to keep my unit entirely stock, feeling that any minor improvement in sound would be a disservice to the true nature of the unit.
With the exception of changing the output coil for the higher bands, everything on the 30K-1 can be controlled from the front panel of the transmitter or exciter. Bandswitching, grid tuning, and output matching are easily accessible.
Collins thought of almost everything with the 30K-1, 310A and 75A-1 station, it really was the dream station of the 1940s radio amateur, and for me remains so today, some 60 years after its introduction.
|The Collins 30K-1 Station at W1UJR|
SK – End Of Work
I delight on bringing back this gear, and while I enjoy using it now, I take additional joy in knowing that I am in, some small way, preserving it for future generations of radio amateurs.
For in many ways I feel that I am not so much the owner, as I am the caretaker of these radios. They are all that is left of the once proud American radio industry, and deserve the best of treatment so they may bet passed on to future generations.
In closing I want to thank Todd Bigelow KA1KAQ for his countless hours of encouragement, Peter Brickey K6DGH for his tireless efforts to get the station to me without damage, Conrad Jahries WB7DHJ for sharing about his father, the good folks on the Collins Collector’s Association email reflector for their information, and finally Walter, W7MGA himself, for building and maintaining such a wonderful station. Your help has been invaluable to help this transmitter live again, and continue to be part of W7MGA and amateur radio’s rich legacy.