With help from many - and especially Carl (N4PY) I have resolved my
Hercules problem. Funny thing, it wasn't the Herc at all. The problem was
Q13 on the control board of the Omni V. I replaced the 2N2222 and
resoldered everything in the vicinity of the TX Out circuitry and all is
well. With Q13 not behaving correctly it wasn't pulling the Hercules relay
adequately - hence the groan/buzzing noise.
Thanks to all who responded.
From: Rick Williams [mailto:email@example.com]
Sent: Friday, February 22, 2002 17:44
To: TenTec List
Subject: Hercules low output / groan
Well it's my turn for an amplifier problem. It looks like the Hercules II
and/or 9420 power supply have decided to act up. The power supply is stable
on TX and the current is indicative of the power out. It's showing about 30
or 40 amps and the output is about 250 to 300 watts. The tell tale
indicator is a "groan" (sort of a high pitched buzz) from the amplifier in
transmit as soon as the Herc relays engage. This happens on all bands into
an antenna or dummy load with or without any drive.
If the groan occurred under load I'd think it might be the power supply but
with essentially no load I'm baffled and unsure where to begin. (I'm
dreading the thought of a failed final - argh!)
If anyone has a suggestion on the troubleshooting please get in touch. Why
do problems always occur after the factory is closed?
Thanks for listening!