Most Popular Tube Transceivers

Discussion in '"Boat Anchor" & Classic Equipment' started by N8FVJ, Nov 30, 2019.

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  1. WA2CWA

    WA2CWA Ham Member QRZ Page

    So (bad; I started with "so") where is this reference to this National kit for miracle caps you mentioned. I checked the targeted web site you gave and did not find any information on it.
  2. K8CCA

    K8CCA Ham Member QRZ Page

    Dave W7UUU, reminded me about my novice adventures with my Eico 753.

    In the early 90’s I was given this radio, complete with a homebrew power supply built from surplus junk from the Michigan Tech engineering lab and had been constructed by a poor college kid that I was friends with. A stern warning was issued with this equipment to NEVER touch anything there when it was plugged it. Now, this power supply was a work of art, multiple transformers with exposed terminal lugs on top, open wiring organized like spaghetti boiling in a hot pot, diodes stapled to the board with wires soldered on, and all mounted to a 1x6 pine board with bailing wire holding the transformers in place. This power supply was a homebrewers dream! Yes, the High voltage B+ was exposed everywhere and as dangerous as it gets.

    I was a new Tech Plus and was working on my CW skill to pass the General test back then. I spent considerable time copying CW tapes, ARRL CW practice, and others QSO’s trying to work my nerve up to answer a CQ over the air. I finally had my chance one Saturday afternoon, when I heard a local ham, and friend N8LDY (SK), who was in the club I was a member of calling CQ. Chuck was sending nice and slow, so I decided that he would be my first CW contact, so I quickly tuned the 753 into the dummy load like I had practiced many times, and then sent my call at about 5WPM, scared to death of making a mistake. After I went back to receive, I heard a different QSO going, and could not figure out what happened. I just didn’t understand what could have happened. So, I just started tuning around and bam, I hear my call being sent by Chuck. He heard me! I go back to him and then back to receive and again, some different CW being heard. I am thoroughly confused, and back to tuning around, and by now I hear Chuck sending to someone else. Very disappointed by my first attempt, I decided to try again, and find another slow CQ, and about the same thing happened, but eventually learned to send with my right hand, and tune the VFO to find the QSO and to copy code all at the same time. It was a challenge for sure, and I am not sure how I did it. Sooner or later, I decided that the heat from transmitting caused a massive change of frequency for the VFO, but recollecting, perhaps it was the voltages changing that was causing the frequency change.

    Later, I was joking at a club meeting about my experiences with the 753 when I heard it referred to as the “seven drifty three” for the first time and it all started to make sense. I had managed to make a few contacts with that radio, but it was tough for sure. Finally, another member of the club took pity on me and loaned me a HW-101 and I never looked back.

    Now I find myself wishing I still had that rig and that homemade power supply. I would like to work on it now as I am much more competent electronics tech to see if I could make it work better. I can’t remember what happened to that rig. I must have given it away somewhere down the road. So, if anyone from the Midwest has an Eico 753 with a power supply built onto a 1x6 pine board, please contact me, I would like to try and get that thing back on the air!
  3. W7UUU

    W7UUU Super Moderator Lifetime Member 133 Administrator Volunteer Moderator Platinum Subscriber Life Member QRZ Page

    Great story. But you really had a couple issues with your "wandering QSO". The Eico 753 shares a VFO trait that other "entry level" SSB/CW rigs of the era had: the VFO is always the transmit frequency! When running CW it's required that you turn on the RIT and tune the receiver to attain a proper transmit / receive offset - 600 to 1000 Hz typically. If you try to receive CW on the VFO dial, you're transmitting either ~700 Hz above or below the received frequency depending on band. You will appear as a "zero beat" to the other station who very likely will tune to receive you - knocking YOU 600-700 Hz up or down the band when you try to reply!

    CW on the 753 is pretty miserable for this reason, as the RIT is just called "Receiver offset" and doesn't give you clue where to set it (the manual probably gives an approximation but nothing on the front panel). At least on the Henry Radio Tempo One, the RIT is clearly labeled CW1 and CW2, with a white line showing you where to put the RIT pointer depending on which band you're on. MUCH easier to use.

    All modern transceivers handle the offset automatically, very often chosen by the user in one of the menus.

    Much of the blame, IMO, of the 753 having severe drift really traces to folks not using RIT properly - and every go'round the other station has to chase you 600-700 Hz because you "keep moving" - that's how they would perceive it - because you are ZERO BEAT to them if using just the VFO for both receive and transmit. Since they seem to be wandering up the dial call after call, they call it "bad drift" when in fact it's simply operator error.

    My 753 drifts - despite being the newer version with solid state VFO - but it's still totally useable for QSOs - I'm in fact almost at all 50 states worked with it.

    Great story!!

    N2EY likes this.
  4. N8FVJ

    N8FVJ Ham Member QRZ Page

    Here is 24 hour stability comment from link listed above: '24 hour longer term testing shows VFO output is held within 20Hz'. I get a few Hz after 15-20 minute warm up.

    As for frequency stability kit (obviously not available now), I read it somewhere, will try to find it.
  5. WA2CWA

    WA2CWA Ham Member QRZ Page

    Taken out of context; you should quote the entire section since he's talking about the improvement using X-LOCK in the VFO.

    Here's the entire paragraph:
    "24 hour longer term testing shows VFO output is held within 20Hz.. This exceeds the designer's specification and makes me smile. Without X-LOCK my VFO drifts 300+ Hz from cold to hot. This was very good for 1967 mind you."
    Obviously means something when you read the entire paragraph.
  6. N8FVJ

    N8FVJ Ham Member QRZ Page

    Pete- go read it yourself, I included the link. The stability has nothing to do with the X-Lock.
  7. WA2CWA

    WA2CWA Ham Member QRZ Page

    I actually found two paragraphs that addressed the VFO stability issue in the link you provided:
    But it is what it is and what one believes - and as I said in a previous post
    "Over the years, I've had here two NCX-3's, three NCX-5's, two NCX-200's, three(maybe four) NCX-500's, and even one NCX-1000, I've never had one that exhibited a 1 HZ per hour drift after warmup. Some were better then others from a drift perspective but none ever achieved a drift of 1Hz per hour. Even my Kenwood TS-830S was never that good."
    - so time to move on with this thread
    N2EY likes this.
  8. W7UUU

    W7UUU Super Moderator Lifetime Member 133 Administrator Volunteer Moderator Platinum Subscriber Life Member QRZ Page

    So now maybe to direct this thread back to "most popular tube transceivers" instead of continued confirmation of the complete lack of drift in your NCX-5 - got that.

    I'll start: Heathkit SB-301/401 in "Transceive" mode is amazing - as well as the Drake "B Line" and "C line" - I was never a big fan of the Collins S-line - the 200 KHz dial limitation was a pain when moving from CW to SSB on the "bigger bands"

    What OTHER tube transceivers do folks like? Regardless of drift claims and all that? Maybe just drop that part for now....

    Just "Most popular tube transceivers" as the title suggests?

    Probably more proper, "most beloved" - because "most popular" would be based on unit sales and Heathkit would win that category hands down over the many years they made tube transceivers.

    N2EY likes this.
  9. HS0ZED

    HS0ZED Ham Member QRZ Page

    I can't help it I'm a confirmed Collins fan boy, even down to the quirky 200kHz vfo, solid technical reasons at the time, operator convenience be damned. But I really like the Drake C line and from Heathkit I think I prefer the SB101/102 transceiver.

    I don't like the Collins S line for split dxing, especially on CW that really these days require you to know whats going on around your own tx frquency. The S line makes no provision for this so it is a bit awkward.

    Anyone interested in a zone 26 contact I will have my S line on tomorrow, (4 Dec) around 11 or 12 UTC, we have a regular sked, usually HS0ZDX, HS0ZDY, K3ZO and myself. Once we are wrapped up with our weekly natter and if the prop is any good I'll take a listen. Might be short path or long, you never know. Will use the 75S-3B, 32S-3 and 30S-1. Antenna is a C3 at about 80 feet over a nice swampy back lot.
  10. N8YX

    N8YX Ham Member QRZ Page

    If I were playing around with Heathkit I'd look into a way to slave an SB-102 to an SB-301. Toss in an SB-610 (hooked to the transceiver), an SB-620 (to the receiver) an SB-200 and my vintage toob station would be complete.

    As it stands, I'm outta space the way it it. :rolleyes:

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