Ed Cregger wrote:
"robo tech" wrote in message
news:mGtmk.286981$yE1.241550@attbi_s21...
If you mean "digital voice", I have heard some on and around 14.235 -
14.236 There are a few programs around that will decode it. It requires a
very clean signal, but when it gets it, it sounds crystal clear! There
are some other bands that people play on, but that should get you started.
kk5h

-------------

Thanks. I've give 14.235 a gander.

I was hoping that it wouldn't take a really terrific signal to decode. I'm
still hopeful, but the added overhead of a digital encryption scheme just
about guarantees either the need for more bandwidth for the same quality as
the analog signal, or a degradation of the analog signal while at the same
bandwidth.

In addition, I believe you have to be listening at the start of a
transmission for the signal to be heard. HF digital won't be the sort of
thing that we randomly tune across a band listening for a CQ. I suspect
for it to catch on, HF will almost need to be channelized. That won't
get rid of the strong signal issue. I'm not really sure of the
advantages of Digital HF over analog, unless it is a simple "Digital is
always better" thing.

A similar situation exists in digital SSTV. The mode can send pictures
of just about any size, but if the receiving transceiver doesn't get the
signal right, it prompts the transmitter to retry. Sometimes the message
just doesn't get through because of noise, QRM, etc.

It's enough of a problem that many suggest not even trying it unless you
are running serious power.


- 73 de Mike N3LI -