Did you give the new tube a reasonable amount of time to "cook in ?"
Do recall that rf parts suggests at least 24 hours, did note when I installed
my new rf parts 3-500, after 24 hours of warming and then putting it to usage
my output was lower than what I expected. Then, not expecting, and three week
later output power had risen to rated amp rf output levels.
73,
Gary... wa6fgi
----- Original Message -----
From: Bob Jones
To: Amps@contesting.com
Sent: Thursday, February 24, 2005 6:54 AM
Subject: [Amps] TL-922 Help
A few quick questions:
1.In transmit mode with no drive,I have 50ma idle plate current on CW and
100 ma on SSB.Is this OK and if not how to adjust?Book says should have
twice this level.Zener checks OK,100 volt supply is OK,both relays check OK.
2.Using the RF Parts ZG tubes and 80 watts drive I cannot drive the amp to
full output.I notice SWR on TS-850 is higher than with the Eimac tubes and
even placed a tuner and different lengths of 50 ohm coax between the 850 and
amp,this helps but still only 400 ma plate current under full load.Plate
volts drop from 2000 to 1900 from no load to full load.Ig rarely gets above
100ma.Have tried tuning input coils using Kenwood method but tuning is very
broad and has little effect on power out.Any ideas and a safer way to tune
the input coils?I do have a MFJ Antenna Analyser and thought I could use it
to look at the coils??
Note:Amp is running on 220 vac primary power.
3.Am presently installing Rich measures supressor kit and hope this helps
the parasitic problem Just lost grid resisters and chokes when one tube went
cathode to grid short,saved the filament transformer though.
Any help on item 1 and 2 would be appreciated and I'll have the amp ready to
put back on the air.
Thanks and 73,
Bob
W0OXJ
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