on 3/14/02 6:39 AM, Mike at W4EF@dellroy.com wrote:
> The problem with the monitor circuit is that even when its done at
> RF, its usually done in one of the low level IF stage. This lets you
> hear what the speech processing sounds like, but doesn't help if
> your problem is downstream (like in the PA). In the case of the
> TS-950SDX I was using a few weekends ago, the monitor gave
> a false alarm as the distortion was due to external RF getting into
> the monitor circuit. The actual RF output was clean as evidenced
> by the received signal on an external receiver (TS-940S).
Very good point. On my 1000D, the monitor samples the RF envelope.
However, on 10M sometimes I get RF into the audio circuit in my headphones
(not sure why - I have a bad headpone jack - could be it). Anyhow, it's
difficult to tell if it's the RF our audio giving me the fits. I recently
interfaced my computer with the rig to do sound card keying, etc. I had
horrible RFI originally due to the computer and so I am very careful with
what my signal sounds like.
If I am not sure, I generally ask folks on the other end how my audio is.
They usually reply back that it's very good. In fact, I always get very
good, broadcast quality type reports. I have also listened to my signal
with another radio and that is helpful too.
So here's a question: how much compression do people use? I many times
will use about 15 dB of compression. I don't really notice my signal
getting worse in terms of how it sounds (at least in the monitor port).
Could it be as well because I am not running my 1000D anywhere near it's max
output (I need less than 100 W to drive my amp to legal limit and the D will
run up to 200 W)?
73,
Jon
NA9D
|