If you want to discuss the 922, phone me.
>Hi Guys,
>I purchased a TL-922A recently and found it has a problem.. Can anyone
>help me
>figure out what's going on?
>The first time I fired it up (using a TS-830S to drive it) I made the
>mistake of having
>it in the SSB position once to measure the carrier output....
The 922 does not have a hv-ps that is designed for carrier/locked key
operation.
A keyer sending 50wpm dits is a better way to go.
>Started to smell funny !
>Bad idea ! Put it back in CW position and measured output with 200ma
>drive at
>about 600 watts.. Started to smell funny again. Reduced drive to
>100ma and
>it seems to behave with only about 500 watts output. (peak reading
>meter)
>My first thought was (and still is) that one of the tubes was shot...
>Having no way to test the 3-500z's and before I invest in new tubes, I
>need some
>expert advise. Does this sound like a bad tube to you guys?
>
>I'm running it with on it's own 240VAC circuit and driving it with a
>TS-830S. I can
>tune to perfect swr with my Matchbox and balanced fed antenna.
>
>I took the bottom off and observed that both tubes have filaments lit..
>( I have heard that
>there is a problem with high filament voltage with these amps and intend
>on making the modifications that Rich Measures recommends.) Nothing
>appears
>to have been burned. All looks clean and normal... Where could the
>smoke been coming from?
When a tube shorts, the unfused filament transformer will melt down
during standby unless the resistor-cutoff bias mod has been made.
SB-220s suffer from the same malady..
> I'm getting a little soured on this rig ...
With a few semi-simple mods, the TL-922 is a winner.
- Rich..., 805.386.3734, www.vcnet.com/measures.
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