[aprssig] Xastir Internet->RF configuration
archer at eskimo.com
Tue Apr 7 14:44:11 CDT 2009
On Tue, 7 Apr 2009, Keith VE7GDH wrote:
> I realize you are using the TNC-X where the TXDelay is set with a pot, but
> for anyone using another TNC where it is set in software, 250 to 400 ms is
> usually much longer than needed. I have reliably used less than 100 ms,
> regularly use 100 ms and suggest about 125-150 ms for someone that doesn't
> want to take the time to see if shorter TXDelay can be used. Yes, if it's too
> short, no-one will be able to decode your tones, but set too long, and it
> uses up valuable bandwidth.
Agreed, except for the range of TXD that works. I usually do tests
with the local digi's, cranking it down until it doesn't work, then
cranking it up a bit from there until it's somewhat solid again.
It's also complicated by the fact that I don't know when my packets
are being collided with by others, so it takes a while to dial it
in. I don't think I've ever had a radio that works with less than
200ms, but I run a lot of old stuff too. Perhaps newer radios are
Also: If you need to sometimes run high power (50 - 65W) note that
it takes a while for the radio to ramp up to max power, so you need
a longer TXD to make that viable. I sometimes head into the
mountains and need full power to make it out of holes/canyons.
Usually I leave it on medium power though, whatever that is (never
can remember, but don't really need to!).
Curt, WE7U. archer at eskimo dot com
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