[AMPS] SB220 Grid current

[km1h@juno.com]

On Sun, 11 May 1997 19:05:17 EDT ko4a3@juno.com (H. J. Kohl) writes:
>Help,
>	The grid current meter on my SB220 is all the way to the right 
>with key down, even on SSB mode of the exciter.  On dekey the meter 
>pegs the left side.  Is this a tube problem or meter circuit problem.  
>  Suggestions please.
>
>	Thanks,
>	John 
>	KO4A@juno.com

The SSB position will worsen whatever the situation John, run the tests
in the CW position with no drive when keying the relay.
A few things to check:

1. the Zener diode
2. the .82 Ohm grid metering resistor
3. One tube at a time

Before doing anything put a back to pack pair of diodes across the meter
terminals. Any 1N4nnn series will be fine. At least the meter will be
saved if something nasty happens. 

If those 3 basic steps check out OK, get back to me and I'll work along
with you. 

73....Carl  KM1H

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