KAM.7

I have seen and heard many complains about the KAM and KPC2,
waiting to long before retying a packet. I had the same problem
and phoned the factory about it. They kind of suggest that there
is no problem, but also tell you to set the following commands.

DW 0
PERSIST 192/63 for the KAM and 63 for the KPC2,
SLOTTIME 5/10 fr the KAM and 10 for the KPC2,
TXDALAY 30.

Well, that didn't realy help a lot.

Looking on page 47 and 48 of the KAM manual or page 36 and 37 of
the KPC2 manual, you will find that for re-transmisions of the
**same** packet, the wait time equals to:
Wait time = (DWait+r*TXDelay)*10 milliseconds
where r is a random number from 0 to 15.

That would mean that the maximum wait time would be 4 1/2
seconds. And it will wait this long **after** the channel is clear
before trying to retransmit the packet. The problem seems to be
that if the channel gets busy before this time is passed, the
whole thing starts all over again. It is called a collision-
avoidence strategy in the manual. Does it ever work. The station
on the receiving end will time out, clearing the frequency for the
rest of us.

Now here is the solution for the KPC2 and the VHF port on the KAM.

From the above equation we see that the dalay is mainly due to
TXDelay, because DWAIT would be set at 0 if we use SLottime and
PERSsist. What you do is set TXDelay to 10 and make the
difference up with  AXDelay 20. That will give you a total of 300
milliseconds of time for the transmitter to key up and the
receiver at the other end to open its squelch. If you need more
time, just increase AXDelay. Also set SLottime to 5 and PERSist
to 10 (yes, ten) in this case. This only works for the VHF
section of the KAM and for the KPC2. There is no AXDelay on the
HF section of the KAM.
CONTINUED IN KAM.8