MFJ MFJ-1270C, Системное руководство

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MFJ-1270C/1274C MANUAL ADVANCED OPERATION
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TNC. Typically you know more than the MFJ TNC does about whether the
other station is still trying or is likely to recover from the latest fade.)
MAXFRAME 1 (multiple frames off) RESPTIME 0(some stations may have
trouble copying your ACKnowledgments (ACKs) when you respond this fast.
This is due to the fact that some radios pump up the AGC voltage during
transmit and if the AGC time constant is long, they are essentially deaf for a
while after transmitting. You will want to experiment with this value. In
general, you will want to use the minimum usable amount.)
5. Set
FRACK to at least 8. A value of 10 or 12 may be better on a very busy
channel.
6. Restrict your use of beacon transmissions as much as possible. If you
MUST use a beacon, keep it short and keep the repetition rate as low as possible.
More than once a minute is definitely too frequent. once or twice in 10 minutes
is more polite. Do not allow your beacons to continue if you are not in
attendance. Nobody wants to connect to you just to be ignored.
7. If your radio allows you to select the AGC time constant (fast or slow
AGC), set it to the fastest setting available to you.
If you cannot select fast AGC, it may be advantageous under some
circumstances to partially defeat the AGC function by reducing RF gain and
increasing AF gain. The demodulator in the MFJ TNC is extremely insensitive
to absolute audio level. It will function properly with input levels from the low
hundreds of millivolts up to many tens of volts. Thus, the variation in audio
level produced by partially defeating the AGC system will not degrade the
modem's ability to copy. The limiting factor on the high end is usually the
ability of the receiver output stage to produce the voltage without clipping. The
limiting factor on the low end is the hundred millivolts or so required to exceed
the MFJ TNC's digital system noise seen at the demodulator input.
MFJ TNC KISS MODE AND HOST MODE
One unique feature offered by the MFJ TNC is that it can be switched into KISS
mode to run programs such as TCP/IP.
Host Mode installed in the MFJ TNC requires a special terminal program to
operate. Documentation for Host Mode is available on disk from MFJ upon
request.