Hello,

I had the chance to step in packet radio with Baycom 1.6 under Win95 with a
Baycom modem. So I had to learn fast to fix the problems and to set the
parameters correctly...

TXD (x10 ms): delay between PTT action and packet frame launching. Depending
on your TRX's PLL quality and the TNC/modem abilities. My FT51r and FT7100
handle TXD of 18 (180ms), the TM-255/455 go down to 12, the T7F (9k6/19k2
packet TRX) breaks the 50ms mark, but that with a TNC2; using a Baycom
modem induces audio lag, so I had to set the TXD between 20 and 22 with the
FT51r. In Europe, when your TXD is too long you get rejected... That's why
you can only expect to work 1k2 packet with an IC-706 (a 300ms minimum is
worse than a CB transceiver, so no Pactor too)

DWAIT/DW (x10 ms): mean time delay between end of reception of a packet
frame and PTT action. If a frame is recieved in this time, there's no keing
up. To give a connection chance to every other station, DW is a random
parameter. For 1k2, a DW of 12 is pretty fair (10 or 12 for 9k6) but less
than 10 is the crocodile way and you get problems with your mates and your
digi sysop.

The packet frame is the audio signal coming after the end of TXD. So if your
TXD is too long and your TRX can handle it shorter, you can connect and get
rejected, or you cannot connect because your frame does not come out in the
DW interval. If your TRX can not handle the right TXD, your packet frame is
cut (and ignored).

9k6 packet is done in FM mode but it is not an F3E signal at all, as the
G3RUH modulation is injected in the TRX after the audio mixer... So long
for the miniDIN-6 (PS2) plug, and there's no need of a mike/TNC switch,
when the 6-pin miniDIN is present.

By the way, there are two different pins on this plug for 1k2 and 9k6, so be
careful, the signal peeks are not the same!

Other important things: Mouse cables are of no use, because even though they
have 5 wires the 6th wire lacks on the wrong pin, so if you only need one
connector, you must take a PS2/PS2 cable which you can cut in two pieces
but no mouse or keyboard cable.
There are two miniDIN plugs on some TRXs, one 6-pin (PS2 type) and one
8-pin; for the TNC you must use the 6-pin miniDIN.

Well, it was a little bit long, but these infos and packet application test
reports are on most packet BBS, so if you find an i-net packet BBS you
should find what you need... Could also be in the europestuff on the
american boxes.


73 de F8BOE Olivier ...-.-