[Amps] GI7B Question - Input Matching

[DF3KV]

The transconductance of that tube is given in the original data sheet at
23mA/V, so the input impedance of a single tube will be 43 ohms.
A 2:1 transformer will match to 25 ohms.

73
Peter

-----Original Message-----
From: amps-bounces at contesting.com [mailto:amps-bounces at contesting.com] On
Behalf Of Lee Buller
Sent: Sonntag, 14. März 2010 21:30
To: amps at contesting.com
Subject: [Amps] GI7B Question - Input Matching


I have been reading about the GI-7B Russian made tube.  It seems that the
input impedance of two tubes is around 100 ohms.  Could you not just use a
2:1 transformer to make a match from 50 ohms to 100 ohms?  What am I missing
here.

Lee - K0WA

 Ham Radio Operators:  Kansas QSO Party is August 28-29, 2010.  See
www.ksqsoparty.org for details

In our day and age it seems that Common Sense is in short supply.  If you
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