[TowerTalk] Using Stubs to Reject Harmonics

Jim Brown jim at audiosystemsgroup.com
Tue Feb 2 13:53:34 PST 2010


On Tue, 2 Feb 2010 15:55:10 -0500, Gary Schafer wrote:

>You should be able to get an idea of the output impedance of the amp at the
>second harmonic frequency by checking with an impedance meter at the output,
>like with an MFJ. You may need to place a resistor from the plate to ground
>of the tube to simulate the tube load. Do all this of course after the amp
>has been tuned up on the operate frequency and then shut down.

Yes, I thought about doing that, but didn't get as far as simulating the tube. You 
can't just shut down the amp though -- you've got to leave it up with the antenna 
relay pulled in. All in all, a lot more work than I have time for right now. But I 
think you're right on target about measuring it. Any suggesting as to the 
resistance to use to simulate the tube?

73,

Jim K9YC




More information about the TowerTalk mailing list