UPS got the MFJ Packet-Pactor Controller to me last evening and
it's a good looking unit. In a box just like the beat-up one on the
mountain but with some added holes. Transmit audio and Monitor audio can
be adjusted through holes in the side. On the other side a hole lets you
reset data in the 2 ram chips.
It operates as a 1200 baud packet OR Pactor TNC, but not both. The
unit has an improved mailbox that can act to forward and ask for reverse
forward from a normal BBS or another 1276. The mailbox has 32 k bytes of
ram and you can replace that chip with one with 512 k bytes if desired.
The books are well written and large. The Fast Start book is
necessary because the book is too large to find things in (280 pages). The
discussion on adjusting the HF radio so that the passband is centered on
the frequency of the tnc is very good.
The hardware is the Z80 cpu and and packet decoder, a phase locked
loop is the audio decoder. There is no filtering of the incoming audio at
all. All the code for packet and the mailbox and Pactor is on a 256k
e-prom. In packet you can make it look like a kiss TNC.
Pactor seems to be fully installed. There is a large number of
pactor control functions. It can be operated either locked at 100 or 200
baud, or switched between the bauds by a settable number of good 100
packets. It has long path correction and Hoffman encoding.
They talk about filtering and say it is very important to have a
500 Hz filter in the IF of the reciever. And you must have IF frequency
shift to center the receiver passband on the TNC's frequency AND tell you
how to do this. If you don't have IF frequency shift you must change the
TNC's center frequency.
Pactor can be run from a simple terminal like minicom and I plan
to do that today. May write scripts to setup the tnc and such. My TS-50
has the 500 Hz cw filter so it might receive well. Will see...
Best wishes
- Karl F. Larsen, [EMAIL PROTECTED] (505) 524-3303 -
