[MRCA] T-195 and Autotune

[doran platt]

Bill,  If the finals are bad, the servo system can't sense power and, 
thus. tune.  I have an "A" model that tries to tune and has high cathode 
current.  This is the classic servo symptom/problem.  The primary items 
to check/replace in this case are the discriminator diodes (the book 
says change them regularly (sic).  The next item is the plug-in 
chopper.  Of course, I'd check the tubes in the servo amp, et al.   In 
your case, with low cathode current, whatever, I'd suspect either the 
final tube or immediately surrounding circuitry.   ER had a series of 
articles on the T-195 and some insights into the tuning system.  The 
book also provides details of the tuning sequence.  Having said all the 
above, physicial heal thyself... I've got to look at mine, too!!!

Good fortune with your repair...   Jeep/K3HVG

Bill Ramsey wrote:

>Hi,
>  I have acquired a T-195 transmitter. Looks real nice on the mount with the R-392. There appears to be a problem with the autotune.
>  Presets work fine, dynos are putting out correct voltage, there is plenty of grid current and the tuning cap in the power amp does seem to adjust. Voltage never sags below 27.5 except when dynos first kick in. The antenna cap unit and the variable coil attempt to tune, at least part way, some of the time. Most of the time they don't move. Cathode current low, output not there. Don't know if the final is good or not.
>  Is there a known "bad guy" part or a common failure in these units. Is there a good web page or series of articles out there that cover problems with the system? 
>
>Thanks,
>Bill 
>KA8WTK
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