[Amps] Vacuum Relay

Paul Christensen w9ac at arrl.net
Thu Dec 13 14:15:57 EST 2012


> A scope isn't going to tell all but it
> tells a lot about a signal.  They're not difficult to use
> and don't have to cost a lot.

It doesn't take long to find some incredibly good buys on used Tektronix 
scopes -- and at a price about half of the popular high-end wattmeters. 
Folks have no problem paying $600 for a wattmeter with unnecessary high 
accuracy, but seem to find no need for a scope.  Is it the number of 
controls that's so intimidating?

The dual trace function isn't required to determine if hot-switching occurs, 
but is required to measure system timing.  For station monitoring here, the 
scope's Channel A is set to trigger on the keyer's output while Channel B 
samples RF.  This setup makes it easy to replicate the same CW waveform 
measurement as shown in the QST Product Reviews.  By triggering the scope 
from the keyer, the waveform stays in place for timing measurements without 
having to chase it with the scope's variable time-base control.

Paul, W9AC 



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