[AMPS] Triode Amp Out/In isolation

[Shawn Tayler]

On Thu, 28 May 1998 09:17:03 +0000, Tom Rauch wrote:

>Oscillations sometimes do, but much more often don't, cause a snap, 
>crackle or pop.
>
>How did you measure the S12 or S21?
>


The measurement was made with an IFR-1200S service monitor in Tracking Generator Mode.  Had a 10dB 
pad on the cable going to the input of the assembly, but no attn on the cable connected to the output connector 
of the amp, I am going to redo the test with an attn there just for SP.  The connector of the amp was connected 
to the Generator output of the TG, level about -20dBm.  The input of the amp had a 10dB pad on it then a cable 
to the input of the SA/TG.  The tune point of the amp was clearly visible on the scope and running all the 
controls moved and affected the isolation but the peak in feedback, so to speak,   was always the 
combination tune point of the input and output, and never exceeded the -14dB.  The feedback then fell off in 
both directions from this peak til it exceeded the range of the SA, about 85dB.  There was one other peak of 
about -50dB around the second harmonic, near but not precisely, of the tuned freq.



de Shawn
 N7LQ (formerly WB7TDI)

The N7LQ station will be on from DN01fa for June VHF QSO '98
50-2304Mhz, 432 EME capable.....Hope to hear you on!!!!





--
FAQ on WWW:               http://www.contesting.com/ampfaq.html
Submissions:              amps@contesting.com
Administrative requests:  amps-REQUEST@contesting.com
Problems:                 owner-amps@contesting.com
Search:                   http://www.contesting.com/km9p/search.htm