Collins 30L1 design questions

Discussion in 'Amateur Radio Amplifiers' started by K9AXN, Feb 16, 2018.

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  1. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    I never had that opportunity, but he's been regarded as one of the "fathers of HF radio equipment" during my lifetime.

    Of course, so have many others. I know Ulrich Rohde DJ2LR and we had offices only 100' apart or so at RCA-Camden. I worked a bit with Floyd Koontz (WA2WVL) at Harris-RF Communications in Rochester back in the late 70s-early 80s and he was another guru.

    The best amp guy I've known locally is the one who designed most of the good Henry amplifiers; he's still around and has his own business making really BIG amplifiers, usually starting at 5kW and going upward from there. He'll still make ham amps, but "starting" with 3CX3000A7s and going upscale from that point. An 8877 is a toy.:p

    In TX, I did work with a few hams who designed broadcast amps at Continental Electronics (your neighborhood, or at least it was back then), but I was doing power supplies and not RF decks. Their 50kW and up systems were tube-based back in those days (1977-1980 or so) and the power supplies were serious...often 10kV/10A (or 5kV/20A) stuff. That was serious fun.
  2. K9AXN

    K9AXN Premium Subscriber QRZ Page

    Johnson used to participate in the frequency measurement group and no-drift contests when the earth was forming. A different era ---- glad to have experienced those years.

    Have you read "Single Sideband Principals and Circuits" Bruene, Senti, and Pappenfus? Explains the 30S1, 30L1, the cable enigma , and a myriad more. Puts the gossip to bed.

    I found your paper regarding the 6146 history very interesting. I believe Collins sold tubes that were special contract as Hallicrafters did. RCA agreed to hand select 8122's in the 2nd quadrant so they could essentially be plug and play not exceeding the max out the SR-2000 was designed to produce. They also provided 6KD6's in the same quadrant (Special contract 274) for the SR-400A. The radio was rock solid and stable when using them.

    Back to the 30L1 design review.

    Regard Jim
  3. K9AXN

    K9AXN Premium Subscriber QRZ Page

    One more comment. I have no problem with directly grounding the grids when using most tubes. The 811A and especially when using 4 parallel tubes I believe to be a serious problem. The direct ground configuration handily violates the design guidelines called out in the tube data sheets as discussed earlier.

    Have a good-n

    Regards Jim
  4. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    I neglected to mention in post #61 above the callsign of the "big" Henry amp's Charlie, KT2J.

    (No clue why he has a 2 callsign, he's a neighbor of mine here in California...I think was originally a JA callsign, but I forgot what it was.)
  5. K9AXN

    K9AXN Premium Subscriber QRZ Page

    Interesting that you worked for RCA. I always liked those folks. Always easy to work with and super accommodating. They were more helpful than most and seemed to be the only tuber that published range of operation for design parameters, others were apparently embarrassed to do so.

    Have a good day
    Regards Jim
  6. K9STH

    K9STH Platinum Subscriber Platinum Subscriber QRZ Page

    WIK / AXN:

    Speaking of RCA: Shortly before graduating from college, I got an offer from RCA to work at the kinnescope factory in Lancaster, PA. I even flew up to Lancaster for a day to look over the plant. There are times that I wonder if my last name had anything to do with the offer. Around Lancaster, there seems to be a Zook on every street corner!

    Actually, Collins Radio did not make the best offer. I think that General Electric offered me like $10.00 a month more to work at their transformer plant in Rome, Georgia. Rome, Georgia, claimed to be the "chicken capital" of the world, processing more chicken for consumption than anywhere else. For some reason, that designation just did not have that much appeal!

    The Collins Radio HR person telephoned me, during the evening hours, about flying down to Dallas and then out to Richardson for a visit (I already had an interview on the Georgia Tech campus). After the arrangements were made, she then said, "You are bringing your wife with you, AREN'T you!" Collins was the first company to even mention my wife, let alone want her along for a visit.

    In Richardson, I got a tour of the plant plus lunch at a local "greasy spoon". My wife, on the other hand, was escorted by the wife of one of the assistant division directors and shown the area. They visited schools, neighborhoods, went to the largest mall in the area that had opened just a few months before, and had lunch at a very exclusive woman's club. Collins was recruiting her! The thinking was that if they convinced her to come to Texas, then she would convince me to take the job. It worked! Well, convincing her to come to Texas because I had already decided to take the job.

    Frankly, the job offered had only 1-level between me and the division director who reported to the vice president who, of course, reported directly to Art Collins. The job was 2-levels above that of newly graduated engineers!

    The Collins 30S-3 amplifier was to be the next product offered to the amateur radio market. That amplifier was based on the 30S-1 but included auto-tune as one of the features. There were 3, maybe 4, depending on with whom you were talking, of those amplifiers produced before Art Collins lost interest in the project and they were not put into production. The late Joe Johnson, W5QBM, who lived just across the golf course from me, had one of those amplifiers. He had to add a switch to disable the auto-tune after tuning up on a particular frequency. This was because the auto-tune tried to follow the changing impedance cause by the audio of the SSB transmissions. After Joe died (we buried him on his 50th birthday - he had been retired from Collins Radio because of a bad heart), the amplifier ended up in Japan with a certain Japanese amateur radio operator paying a fortune for the amplifier plus the shipping charges.

    Art Collins had a bad habit of wanting certain products designed and then, after a while, losing interest in the project and shutting down future development. The KWM-3 amateur radio transceiver was one of these projects. This transceiver was to be based on the 718-T avionics SSB transceiver with the lower frequency end being moved down to 1800 kHz to cover the 160-meter band.

    The Industrial Design Department had been charged with designing the cabinet for the KWM-3. This department, headed by Eric Tedley, was assigned to the Process Division in which I worked. One day, just 2 or 3-weeks after I went to work for Collins Radio, Art was scheduled to come over, from Building 407 (a.k.a. Camelot - King Arthur's palace) to Building 401 to look at the proposed designs. One of the assistant division directors (in fact it was his wife who had escorted my wife on our initial visit to Collins Radio) knew I was an amateur radio operator and invited me to the unveiling. This was the first time I ever met Art Collins.

    There were 3-designs, including a wood grained version, presented. Art looked at the designs and then said that he would let Tedley know which one he had decided for production. That was the last thing that was ever done on the KWM-3. Art lost interest in the KWM-3, he had decided that Collins Radio Company was going to build a better computer than IBM, and the project was cancelled. HF-380 / KWM-380 was several years in the future and was a completely different design.

    Glen, K9STH
  7. WB2WIK

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    I visited the transmitting tube operations in Lancaster and the receiving tube operations in Harrison several times but actually had nothing to do with either one.:p

    RCA in Camden is one of its oldest original locations, sited where The Victor Company originally was ("His Master's Voice" and Victrola, along with Nipper the dog) and then of course expanded by RCA. The original "Victor" (little Nipper) building became RCA Building #17 and is now condominiums I think (haven't been there in about 30 years).

    But, under RCA it was also headquarters for Broadcast Systems Division and Government Systems Division which designed and manufactured everything from television cameras to broadcast transmitters and military communications equipment (transmitters, receivers, amplifiers). That's what I was dong.

    If you're familiar with the sort-of famous AR-88 receiver (WW2 vintage), that came from RCA Camden.
  8. WB2WIK

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    Amish country!:) Some of the restaurants around there are fabulous.

    I've been to the Lancaster plant probably a dozen times or so but never worked there or really had anything to do with it. It was actually a Navy plant (designation). But that's where a lot of the transmitting tubes came from, up to and including the 8122s and stuff and my visits were more related to ham radio than employment. That plant is now Burle Industries.
  9. K9STH

    K9STH Platinum Subscriber Platinum Subscriber QRZ Page

    Lancaster, PA, is the only place that I have seen hitching posts, for horses, in an airport parking lot! Since there were balloons in use even before the Civil War, it would be logical that airplanes are an extension of those and, as such, would be OK for the Amish to use for transportation. They do use the railroads for transportation.

    Of course, the Amish are a sept of Mennonites and the Amish are much more conservative than the average Mennonite. My Swiss ancestor, Hans Zaugg, was a Mennonite minister and was imprisoned for being such by the Swiss. The area that is now Switzerland was Catholic and anyone who was not Catholic was often imprisoned, even executed, for not being Catholic. It was just the opposite in the old Dutch empire. That is, Catholics were often persecuted, imprisoned, and, in rare instances, executed. Then, someone in the Dutch empire got the idea to exchange their Catholics for non Catholics in the Swiss Cantons. After 7-years in prison in Berne, my ancestor moved to the Darmstadt area of Germany and his sons went on to Brussels which was then part of the old Dutch empire. Finally, 3 of Hans grandchildren (and their families) came to the British American Colonies in 1719 and 1721. Zaugg became Zugg, then Zug, and finally Anglicized to Zook. Americans have been "stuck" with us since 1719!

    However, my wife had ancestors who came over with the 1st, and 2nd, group at Jamestowne and I had an ancestor who came over with the 3rd group about 18-months after the 1st group. As such, we have been here since 1609! That is 409-years! Although I did not meet my wife until 1964, our ancestors knew each other back in the early 1600s!

    Of course, all that has absolutely nothing to do with the design of the Collins 30L-1 amplifier! I keep referring to the 30L-1 amplifier because there was a 30L-1 transmitter.

    30L-1 3a.JPG

    Before many of these were manufactured, Art Collins decided to change the nomenclature to KWS-1. However, if you look close at the examples in the early advertisements for the KWS-1, you will see that the unit actually has 30L-1 on the escutcheon.

    The 30L-1, 32W-1 SSB exciter (which was dropped after only a handful were made), and the 75A-4 receiver were advertised in the 1956 ARRL Amateur Radio Operator's Handbook, in a full color, 4-page "spread". I do have a number of reproductions of this 4-page spread left over from a major meeting held a while back in Dallas that were made for sale. A goodly number of the reproductions were sold, but not all of them. Gradually, most of the advertisement have made it out the door but there are still a few remaining.

    Glen, K9STH
    K9AXN and KD2ACO like this.
  10. KD2ACO

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    That setup looks perfect for 'field day', Glen!

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