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Help with palomer tx-100, relay issue.

Discussion in 'Amplifiers' started by T23, Jul 5, 2011.

  1. T23

    T23 Active Member

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    I just got a palomer tx-100 in off craigslist and was told it worked fine, it wont key up unless I use AM on SSB mode WITH the pre amp on. I put a dk if 3.5 watts in. What could be the problem? I think it might be the diode across the relay because it does nothing at all on AM.




    T23
     
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  2. fodendaf

    fodendaf Active Member

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    I d0‹2nt know much about linears but i do know the diode across the relay prevents back emf from the relay from damaging the keying circuit. Since the linear is keying i would say that is not at fault
     
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  3. TonyV225

    TonyV225 Supporting Member

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    Its not the diode Im sure Im thinking dirty sticky relay?? So its not showing anything in the AM setting just on SSB?
     
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  4. T23

    T23 Active Member

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    That's correct Tony , but I have to modulate too, it won't work on SSB with just the deadkey. It also won't work on SSB unless the pre amp switch is on, won't work AT ALL on AM.


    T23
     
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  5. AudioShockwav

    AudioShockwav Extraterrestrial Admin Staff Member

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    Where the radio hooks to the amp, on the inside there should be a small value Cap, this cap Sniffs the RF coming into the amp, and if the power switch is on, should trigger the relay (s) It might be bad or going bad.
    If you can post a picture of the inside of the Amp we should be able to figure it out.

    73
    Jeff
     
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  6. eagle1911

    eagle1911 Active Member

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    Most RF-keyed amps won't work with a "dead key" on SSB since there is no such thing as a dead carrier when talking about sideband modulation. When you dead-key a mic on SSB, there is no output at all from the radio. Only when you begin speaking is there output, and it's in proportion to the volume of the audio input. It's perfectly normal for nothing to happen in an amp on SSB until you speak or add some other form of audio.

    Not sure why you're getting nothing on AM though..
     
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  7. AudioShockwav

    AudioShockwav Extraterrestrial Admin Staff Member

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  8. T23

    T23 Active Member

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    Eagle, I have my radio on AM, I have to put the amp on SSB for it to key up.

    This does not explain though about the pre amp having to be on for it to key at all.

    T23
     
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  9. T23

    T23 Active Member

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    Is it the 10uf capacitor inline with the rf input on the schemaic? I have a couple of 10uf 16 volt caps here if that's the case.

    T23
     
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  10. AudioShockwav

    AudioShockwav Extraterrestrial Admin Staff Member

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    Yes, that is were I would start, and it is 10 pf ( pico farad`s ) or as us old timers sometimes call them 10 Puffs (LOL)

    .00001 micro farads = 10 pico farads

    It will be a little ceramic disc capacitor, not an electrolytic.
    I do not know if Rad Shack carries them any more or not.

    The 22 mfd is used for the timing of the SSB delay.

    73
    Jeff
     
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