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Trivia on Amateur Amps that had sweep tubes!?!?

Discussion in 'Home Brew' started by ElectronTubesRule, Sep 15, 2011.

  1. ElectronTubesRule

    ElectronTubesRule Active Member

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    Ok so I have looked at prob. 200 different old black market amp designs, home brew Ham designs and all of Heathkits, Dentron, and Alpha's popular models. I have been trying to cherry pick those feature I like in the various designs. Because I can read Russian and German I have been looking at their designs too. Although I will say my technical Russian is not even close to my German. Do not waste you time trying Googles Translation matrix it butcher's the Russian to the point that it is often gibberish.

    So Swan and Kenwood both had models marketed to Amateurs that used 6lq6 tubes or tubes in that family ie magnoval 9 pin with cathode cap. Everyone thinks no legit amp designed for Amateurs used cheap sweep tubes but at least these two companies made models with them.


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  2. WA2SI

    WA2SI Member

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    You will find that peoples' bias' often affect their memories.

    Sent from my ADR6400L using Tapatalk
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  3. Captain Kilowatt

    Captain Kilowatt Professional Amateur Staff Member

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    I don't know about "everybody" thinking that way. there were more than you think. Ameritron had the AL-84 that had four 6JM6 tubes in it. Sweep tubes were even used in a Yaesu amp, I forget the model FL-2500 maybe, used 6KD6's and the FL-1000 used 6JS6A's. Yaesu used sweep tubes in the finals of the FT-101 series, 6JE6 I believe. There were a lot of legit stuff using sweep tubes.
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  4. wavrider

    wavrider W9WDX Amateur Radio Club Member

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    Break it down to simplicity.

    A final (tube), either sweep tube, transmitting tube etc etc, it depends on what circuit the tube is used in.

    It may be in a television set and be a horizontal output, same tube installed in an amplifier is now and RF transmitting tube.

    Sweep tubes were cheap back in the day, in the right circuit they even worked as an HF amplifier and well into the VHF freqs also.

    Heck look at the ARRL website under amplifiers archive, they still have sweep tube amplifier plans and schematics on the official amateur site.

    So sweep tube is just a tube, do not stereo type it as a CB amplifier tube because it is not.
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  5. W5LZ

    W5LZ Crotchety Old Bastard

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    One of the 'keys' to which tube to use is availability and cost. If you happen to have a boxcar load of sweep tubes, sure, why not? Other wise, while they may work, they just aren't very practical.
    - 'Doc
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  6. Kamikaze

    Kamikaze Active Member

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    Galaxy WRL made a 10 sweep tube legal limit amp.

    Nothing wrong with sweep tubes at all except many amps run them so hard.

    Some of the very worst linear amplifier tubes are the 6146 and 4CX250B.

    The feedback needed to clean them up can be applied to sweep tube amps with excellent results.
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  7. wavrider

    wavrider W9WDX Amateur Radio Club Member

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    Good point Mack, SWAN sold many tube rigs using sweep tubes as finals, they were bottom line for amateur rigs ( ok start the flaming on the bottom line comment) but they worked, as long as you did not mind driving the vfo to keep it on freq.
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  8. Kamikaze

    Kamikaze Active Member

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    And Drake sold a lot more with sweep tubes. Drake was considered top quality.
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  9. ElectronTubesRule

    ElectronTubesRule Active Member

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    Well someone challenged me on that issue on another site. Because I was referring to an Amp that was clearly marketed towards illegal CB user's but was tagged with a plate and sticker as a 10m/6m Amateur Amp. So I have been keeping an eye out for any legit Amateur marketed gear that had them in it. I am young 37 years old and am still taking class's at the Red Cross with my son to become Licensed Amateurs! So I had no idea where to look and was not going to dig for it on purpose but just kept and I out. So when I came across it I figured I would post it. The Technician that challenged me on that is at least 20-30 years older then me so odd that he had such selective memory about this!

    Yes, i am a big believer that parts have no idea where their going to end up and who they will be marketed to! So really it comes down to a design by design basis. I say that because I have two such amps and one is an absolutely beautifully executed single band 40 year old HF amp with sweep tubes. The other unit is a nightmare of poor design, poor execution and all kinds of band aid's inside to try and cover for poor design!
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  10. mackmobile43

    mackmobile43 Jock Supporter

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    True the Drake was top of the line in the day as were Yaesu's and I believe these guys started getting away from the sweep tube to satisfy the hard core hammy as the cb craze got into full swing and with the availability of cheap sweeps to make illegal cb amps the big hf rigs switched from those to keep customer relations up this the hammy's.
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  11. office888

    office888 Active Member

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    Close!

    6JS6C in the FT101.

    Later zed series got swapped for the stout 6146B, a proper RF amp tube.
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  12. BJ radionut

    BJ radionut Supporting Member

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    The switch from Sweep Tubes had nothing to do with PR and the Ham's standards...it had everything to do with the changes in advancing technology of transistors and solid state.
    The Amateur community still relishes and embraces the sweep tubes IMO Have you seen the prices on the Drake TR-4C (W)(rit) versions lately...through the roof
    I love those rigs T4XB/R4B none better!
    My SWAN 700S certainly drifts a helluva lot less than most of the Galaxy's /Ranger CB's... I've seen on the bench!
    What would we "Hammy's" be using if it was....
    If the CB world uses it! Then we don't want it!
    OH I'm sorry you use PILLS....We use transistors!:pop:
    All the Best:D
    BJ
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  13. mackmobile43

    mackmobile43 Jock Supporter

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    Is the ft101-z a hybrid? I wasn't aware it was.
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  14. office888

    office888 Active Member

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    Yep!

    ZD was a 12BY7A driver with a 6146A final.

    My Heathkit DX40 has a 6146A as the final...great little tube.

    The FT301-series was their first all solid state rigs.
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  15. Captain Kilowatt

    Captain Kilowatt Professional Amateur Staff Member

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    Another radio with sweep tubes was the Yaesu FTdx-400/401 that had 6KD6's in the finals.
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