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Old February 26th 14, 02:40 AM posted to rec.radio.amateur.boatanchors
Scott Dorsey Scott Dorsey is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 774
Default Heathkit HW-16 T/R Switching Noise

Channel Jumper wrote:

From the Eham web site -

The HW-16 is not a transciever except in name only.
It is a separate transmitter and receiver housed in a single cabinet
which happens to use the same power supply.


[stuff deleted here]

All this stuff is true, but I am not sure it has any bearing on the orignal
poster's question.

I believe that the T/R switch here is doing two things: muting the received
audio and moving the antenna connection. If the timing between these two
things is not good, there will be a thump. If the muting shifts the DC
offset of some stage (say, because a blocking cap is leaking), there will be
a thump.

I believe that this transceiver thumped somewhat when it was new, so I am
not sure to what extent the issue is misbehaviour vs. perception. But I
would bet a youtube search would find some videos of some other people using
the rig so you can compare the behaviour.

This would be a very fine rig for use on 60M where the crystal control is
not an issue.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."