[AMPS] RE:30L1/30S1 tuning (was: linearizing linears)

Pete Smith n4zr@contesting.com
Tue, 26 Sep 2000 10:22:35 -0400


Peter Chadwick wrote:
...
>> I believe the '220pf to ground caps' business got used first in the 30L1.
>> The simplified schematic I have suggests that the ratio of grid to
>> filament RF volts were used for establishing correct tuning and loading,
>> which seems a little strange. It may be that approach works with 811As,
>> but I agree with Tom that is isn't a general approach.
>
>Let's look at that.
>

Yes, indeed.  Can any of the Collins aficionados out there affirm just how
the 30S1/30L1 "tune" system works?  I can remember tuning a 30L1 by the
book, and being told to dip with the Tune cap and then add Loading until
the meter returned to the zero center point, redip, reload, etc.  But I
never knew what was being measured or what the significance of the "zero"
point was.

73, Pete Smith N4ZR

Contesting is ... Extreme Radio

The World Contest Station Database 
is back up and running at
http://www.qsl.net/n4zr 



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