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[aprssig] Xastir Internet->RF configuration

Curt, WE7U archer at eskimo.com
Tue Apr 7 19:44:11 UTC 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
faster.

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
http://www.eskimo.com/~archer
   Lotto:  A tax on people who are bad at math. - unknown
Windows:  Microsoft's tax on computer illiterates. - WE7U.
The world DOES revolve around me:  I picked the coordinate system!"



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