Hi Steve,
Did you check the plate dropping resistor to the driver? They go high,
and still can supply enuf drive for the low bands, but not enuf for 15 & 20.
73,
Al, W8UT
www.boatanchors.org
www.hammarlund.info
"There is nothing -- absolutely nothing -- half so much
worth doing as simply messing about in boats"
Ratty, to Mole
On 4/24/2012 8:11 PM, Steve Wedge wrote:
I played around some more with WA1HZK's T-4X this afternoon and found a
few interesting things:
No output on 15m: swapped a crystal and got about 60W out.
Very low (10W) on 10m. Receives fine on TX and RX. Tried peaking the RF
TUNE and got a little more but not much.
No output on 40: receive works fine on TX or RX, tried peaking the RF
TUNE circuits and found the rear (driver plate) doesn't peak. Probably a
bad capacitor but haven't confirmed.
No output on 80m: exercised the bandswitch some more and got well over
100W out. Chalking this up to a dirty switch contact.
No sidetone: I can hear a faint drone all the time, so I'm suspecting a
dried-up electrolytic can. BTW, I can key it on CW just fine and the
meter responds to mic inputs on SSB mode.
The meter seems to be erratic.
The finals definitely need to be neutralized: peak output even on 20m
doesn't correspond to the dip.
I've not had a rig to fix with this many problems in quite a while.
There are no apparent hacks - just the effects of humidity and no use
for years, I guess.
I can get well over 100W on 80 and over 100W on 20, but the output drops
to 60W on 15 and about 10W on 10. This looks like a soft final amp to me
- any opinions? Is it worth my trying to neutralize it first, or will I
be wasting my time? I've never really had one of these with worn-out
finals before but this sounds like what I've heard.
73,
Steve Wedge, W1ES/4
"Just so the wealth of the country, its capital, its credit, must be
saved from the predatory poor as well as the predatory rich, but above
all from the predatory politician."
- James Jerome Hill
All my computers have my signature with various pearls of wisdom
appended thereto.
_______________________________________________
Drakelist mailing list
[email protected]
http://mailman.zerobeat.net/mailman/listinfo/drakelist
_______________________________________________
Drakelist mailing list
[email protected]
http://mailman.zerobeat.net/mailman/listinfo/drakelist
