First I have a question. How does a voice keyer send CW?? Or
does it have a CW key output?
To correct some misinformation about the MFJ432, it has been
ground isolated since I was given the job of reworking it a few years
ago. The small chokes were NEVER for ground isolation, they were
for RF isolation.
The original MFJ VK switching scheme was FET's (duh) and it
originally had no audio isolation transformer (double duh). Nether
were good ideas.
It was also hand wired, it is now surface mount.
As far as I am aware, the only recent problems come from a batch
that may still be out at dealers where an assembly line inspector
let units out that were not stuffed with all the parts, or were not
soldered at the correct temperature in the wave solder machine.
Since MFJ does not serial number units there is no way to trace
these other than popping the cover and looking next to the jumper
terminals for missing or partially soldered ferrite beads.
Other than that batch, any VK within the last two years or so
should all work with any radio and not have any significant audio
quality issues. If they don't, I would like to know about it because
that means I missed something!!
73, Tom W8JI
W8JI@contesting.com
--
CQ-Contest on WWW: http://lists.contesting.com/_cq-contest/
Administrative requests: cq-contest-REQUEST@contesting.com
|