Amps
[Top] [All Lists]

[AMPS] SB220 Grid current

To: <amps@contesting.com>
Subject: [AMPS] SB220 Grid current
From: km1h@juno.com (km1h@juno.com)
Date: Sun, 11 May 1997 23:34:08 EDT
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

--
FAQ on WWW:               http://www.contesting.com/ampfaq.html
Submissions:              amps@contesting.com
Administrative requests:  amps-REQUEST@contesting.com
Problems:                 owner-amps@contesting.com

<Prev in Thread] Current Thread [Next in Thread>