How I do tune a tube radio into an antenna tuner

Discussion in 'General Technical Questions and Answers' started by VE3PCD, Sep 5, 2010.

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  1. VE3PCD

    VE3PCD XML Subscriber QRZ Page

    Hello all !!

    Can someone please tell me the correct procedure to tune the FT-101E into the Pulstar AT1KP tuner?

    I cant seem to be able to get the swr down, I tune the radio but then unable to get tuner correct the swr....What am I doing wrong?

    thx.

    Peter
     
  2. AF6LJ

    AF6LJ Ham Member QRZ Page

    By first tuning the tube radio into a dummy load then tuning the tuner with the radio connected to the tuner.

    One of the nice things about some of the MFJ tuners is they have a built in dummy load....
    It's just a switch throw away.
     
  3. KD0CAC

    KD0CAC Ham Member QRZ Page

    I am posting more to see than answer , but have some idea's .
    I found with working a club station how to tune on frequency and not QRM others on that frequency .
    Have a antenna analyzer in the circuit with a switch that would be to switch from radio to analyzer , then watch the analyzer while tuning , the tuner on the exact frequency you want to work , now that you have the tuner tuned , turn switch back to radio & tune the radio .
     
  4. KE3WD

    KE3WD Ham Member QRZ Page

    Here is one method, tried and true, with the idea of not getting into territory that can damage output tubes and components in mind:

    Use of a 50 ohm Dummy Load and an antenna switch arrangement that allows you to switch between Dummy Load and Antenna Tuner at the Tuner's input can really help.

    Tune up the '101 into the Dummy Load first.

    Now you have the '101 all set to yield full power into 50 ohms.

    Reduce the power of the '101 and switch over to the antenna tuner, and, as rapidly as you can, tune the tuner. It is better to do short transmissions and tune the tuner, stop transmitting for a sec or two and repeat the short tuning transmission picking up where you left off IMO.

    Can't stand those !#$&%$ "half hour" tuneups on the bands, and neither can your finals or the components in your tuner.

    Writing down the settings for a certain band area so that you can place the tuner controls to those settings when returning is a very good idea. Then you can spend less time in the tuning to get to the optimum point since the controls will already be somewhere near the right places. Some hams place paper stickers at those points on the dials of their tuners (and linear amps) as reference points for the various bands they use, a fine idea for spending less time on the tuneups and more time on the air as well as a good way to have some reference points that would indicate to you any problems that can happen to an antenna system before such can damage components in the tuner - or even the rig itself.

    If you don't have a good 50 ohm Dummy Load that can handle the output power of your '101, now is a good time to start thinking about picking one up, along with that antenna switch. Every ham should have a good Dummy Load handy.
     
  5. KD0CAC

    KD0CAC Ham Member QRZ Page

    Sue beat me to it .
    I have a further question .
    If there may be some discrepancies between the dummy load , tuner , feedline and antenna , would the radio tuned into the dummy be a little off ?
    Probably close enough though , many ways to skin a cat .
     
  6. AF6LJ

    AF6LJ Ham Member QRZ Page

    It wouldn't be off when tuning the tuner for lowest VSWR.
     
  7. KD0CAC

    KD0CAC Ham Member QRZ Page

    I was referring to tuning the radio into the dummy load .
    But I have not owned or operated a tube radio yet .
    Just got two amps , non operational and repairing , a Heathkit SB-201 and a Collins 30L1 .
    After getting my ticket , I thought that having to learn ham radio on older rigs would be a better learning experience , because of the solid state rigs turn on and go , instead of what had to be known and set manually with the older rigs ?
     
  8. AF6LJ

    AF6LJ Ham Member QRZ Page

    I believe when you have an older tube radio, especially one well metered you do learn more.
     
  9. AG3Y

    AG3Y Ham Member QRZ Page

    A major un-answered question. What mode are you using to tune your setup? Of course, you need to use a continuous carrier to tune the rig, and the auto-tuner needs to see a continuous low level carrier in order to tune for lowest SWR. (probably around 5-10 watts) Are you attempting to tune the antenna tuner with a low-level continuous signal, or are you assuming that you can tune it with a voice signal in SSB ?

    That will not work. You MUST use a low level continuous signal!
     
  10. K0RGR

    K0RGR Premium Subscriber QRZ Page

    Yes, back when radios glowed, a dummy load was a fairly essential shack accessory, and this is part of why. A dummy load is the right way. The wrong way is to get the transceiver tuned up well enough to put out a signal that you can use to tune the tuner, then go back and refine the tuning on the transmitter. However, after you've tuned things up a few time, you'll have some idea of what the setting should look like on both the tuner and the transmitter, and you'll be able to get fairly close without much tuning.

    It's always a good idea to keep track of your settings for each band, just for this reason. It will also tell you when something changes, which may be an indication of a problem somewhere.

    Another option would be to use an SWR analyzer or a noise bridge to tune up the tuner before tuning the transmitter. Noise bridges were also fairly popular in the latter tube days.
     
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