[TenTec] Heil ProSet adapter with Orion -- hum

[Duane A Calvin]

Thanks, guys - there have been some very useful ideas to try in the
various notes.  The most lucrative to me look like the ones talking about
separating the shields/grounds.  Should be interesting since the Heil mic
is only a two-wire affair, not two with a shield.  But I will look into
it.  HOWEVER - I can't stress enough that I don't think this is an RFI
problem!  This "hum" is present regardless of power output (1 - 100 W),
and regardless of whether I send power to an antenna or a dummy load. 
Changing the power supply didn't help.  Strangely, it appears to be an
"intermittent" at the front mic connection with only the Heil.  I cannot
replicate any of the problems (intermittent or hum) using either my TT
hand mic, or the TT 706 mic.  The solder connections on the Heil adapter
are good, so I"m starting to wonder if it could be a "loose" pin (i.e.,
expanded so that it doesn't contact well).  This is a very strange bug,
and my next approach will be to completely rebuild a Heil adapter of my
own.  Like George, I've also had footswitch induced RF problems in the
past, but this is not one of them.  I can unplug the footswitch with no
improvement.  

Thanks again - and when I finally isolate the cause, I'll post again.

        73, Duane


Duane Calvin, AC5AA
Austin, Texas