Hi Scott, Rohre and group,
> You must be using hi fi phones rather than communications, limited band, 300
> to 3000 Hz phones. If you use high impedance phones, or Comm phones, you will
> not hear this noise which is the microprocessor noise. It is only detectable
> on mine if I use very HI FI phones. An audio filter helps, but the better way
> is to listen to HF with communications phones so your brain and ears will not
> tire from extraneous noise. You might try better power supply bypassing on
> the audio stage if it is established that it leaks into the audio via that
> bus. I did not go to the trouble, when I found mine worked so well with
> Military phones.
hi fi phones and most modern comm phones are low impedance and will not work
with a Scout unless you pad them. Ten-Tec told me the phone jack on the Scout is
not a phone jack, it is a speaker jack. High impedance phones should work ok,
where do you find them? I haven't been able to. An audio filter is not
you need to get the audio amplifier up into it's useful range. A 10 ohm resister
in parallel and a 470 ohm in series should do it. They should fit inside the
stereo phone plug.
Incidentally, Ten-Tec told me they designed the Omni 6 along the same lines as
the Japanese rigs, to work well with cheap stereo headphones.
73, de Art WU2K
72,73, de Art Searle, WU2K, Long Is., NY, ARRL Life Member
QRP-L #524, QRP ARCI #9123, NorCal pending, DXCC MX & CW HR
NRA Benefactor Life Member, NMLRA Life Member, AMA Life Member
NRA Certified Firearms Instructor, Dale Earnhardt Fan Club