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Old January 12th 05, 02:00 PM
Charles Brabham
 
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Howdy, Bob!

"Bob Bob" wrote in message
...
Hi Charles..

Some comments on your article.

- Using a voice repeater is in a sense like using a bit regenerative
device albeit with no intelligence. The great thing about it is that it
avoid the hidden transmitter problem as repeaters are often built in high
places. Straight digi's or popular nodes on top of hills get messed up
really quickly when one station cant hear another and transmits on top of
them. We use to have a system in NSW that was continually getting into
packet crash problems because it was badly designed. With one user at each
end of the circuit it was great but anymore than that and it was an abject
failure.


That sounds like a job for DAMA, which gets you past the dubious idea of
having all Packet ops at high power in the forlorn hope that they will all
be able to hear each other.

There is danger of a collision while connecting to the DAMA capable node,
but none after that as your station will not transmit therafter until the
node polls it, giving it an OK to do so. Everybody waits their turn, be they
near or far, powerful or QRP.

Since user stations no longer have to hear each other in order to access the
network, then low powered stations using yagis can be set up for network
access with little or no hidden transmitter - related problems. - You can
then attract more users because it's easier and less expensive to
participate, not to mention the fact that it will all work much better.

Most TNC's have DAMA capability built-in, and some soundcard Packet stuff
has it. The free PC-FlexNet node system offers DAMA access as an option.
Switching over to FlexNet with DAMA access would magically cure your Packet
network's ills, and improve its performance in other areas at the same time.

As with any change, a few will be inconvenienced and its up to their fellow
hams to soften the blow by giving them a hand... Kind of like installing a
tone board for a guy with an old VHF rig who can't get on the repeater. The
price for improved performance would include some promotion and legwork,
visiting hams who need help using DAMA access.

DAMA access is used extensively in Europe, where Packet never really lost
its popularity. It's hardly ever been used here in the US...

- I would suggest that the repeater stays on during both sides of the data
exchange.


That sounds very interesting! I'll try to find out if I can get it to fly,
as that would open up the possibility of speeding things up significantly,
as you say. It's sure worth a try.

Charles, N5PVL