Topband: Loud clicks

[Paul Christensen]

> this discussion "does not apply to me".  For those of us with a scope,
> great, use it.  But, if you don't have a scope, simply ask a fellow ham
> to monitor your signal periodically.

Excellent advice, although anyone who can afford one of the popular 
late-generation SWR meters can certainly afford a used dual-trace 
oscilloscope.  Quality scopes are plentiful on the used equipment market and 
they don't need to have lab-grade accuracy in order to detect the presence 
of hot-switching.  I have identified several timing issues over the years 
with a scope that would not have been identified by ear alone.  By the time 
the problem is identified by others, needless QRM has already resulted.  At 
the very least, a scope should be borrowed with any major equipment change 
(e.g,  the changing of a transceiver or amplifier) to ensure that system 
timing is accurate after the system change.

For the past fifteen years, I've been using a monitoring system like that 
used for the QST Product Reviews:  The station RF sample is routed to scope 
Channel A.  Channel B is DC-coupled to a spare output from a microHam CW 
keyer which applies a buffered + 5VDC on an auxiliary RCA connector.  The 
scope is then triggered by Channel B and the displayed waveform looks 
identical to those that appear in the product reviews.  Triggering the scope 
from the keyer keeps the waveform stationary for measurement purposes 
without having to chase the waveform as is common when external scope 
triggering is ignored.

Paul, W9AC