[AMPS] Any Ideas

[Rich Measures]

>
>I have an old (Late 60's) boat anchor 4-1000, grounded grid amplifier,
>rescued form a storage building, complete with spider webs and mud dauber
>nests. It was originally an 80 meter monobander.  Spent a lot of time last
>year getting it working.
>
>Finally got it going on 160, 80 , and 40 meters last December.  When
>building the input coil, I never put a tap for 20 meters as I never thought
>I would use it on 20 meters.  It put out about 800 to 900 watts on 160, 80,
>and 40 meters.  I used it on 20 meters running it through the 40 meter
>input with a tuner.  About 500 watts out like that.
>
>A month ago, I decided to change the input circuit, it is an L, so I could
>add 20 meters.  It hasn't worked since.
>
>It behaves similiar to when I first tried to get it operating and the relay
>to ground the center tap of the filament transformer was not working ie, no
>output.
>
>I cheked that first as the symtoms were the same.
>
>Ohmeter between filament leg and ground, no high voltage on tube is 3.8
>volts.  With HV on plate it is 14 volts,with transmit relay closed
>(grounding filament center tap) 0 volts,  when I tried loading it with
>voltmeter in this position, it arced inside of the tube so I quit.
>
>........
>Any thoughts, ideas are appreciated.
>
A g-g amplifier needs a separate pi-network input circuit for each band.  
A Q of two (XC1=25 ohms) seems to work well.  



Rich...

R. L. Measures, 805-386-3734, AG6K, www.vcnet.com/measures  


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