Date: Sat, 31 Jul 93 04:30:07 PDT
From: Advanced Amateur Radio Networking Group <tcp-group@ucsd.edu>
Errors-To: TCP-Group-Errors@UCSD.Edu
Reply-To: TCP-Group@UCSD.Edu
Precedence: Bulk
Subject: TCP-Group Digest V93 #195
To: tcp-group-digest
TCP-Group Digest Sat, 31 Jul 93 Volume 93 : Issue 195
Today's Topics:
9600 Baud Packet Radio Handbook
9600 Experiances (2 msgs)
9600 Modems/Radios
9600 Radios
Firmware PK-88 23.AUG.91 (2 msgs)
KISS parameter 6 (2 msgs)
Micor identification and crystals (was: Micors at 9600 baud)
Micors on 9600 (5 msgs)
NOS on MS-Windows? (2 msgs)
source of wider if filters.
TCP-Group Digest V93 #194
Undelivered mail (4 msgs)
Send Replies or notes for publication to: <TCP-Group@UCSD.Edu>.
Subscription requests to <TCP-Group-REQUEST@UCSD.Edu>.
Problems you can't solve otherwise to brian@ucsd.edu.
Archives of past issues of the TCP-Group Digest are available
(by FTP only) from UCSD.Edu in directory "mailarchives".
We trust that readers are intelligent enough to realize that all text
herein consists of personal comments and does not represent the official
policies or positions of any party. Your mileage may vary. So there.
----------------------------------------------------------------------
Date: Fri, 30 Jul 1993 00:12:27 -0600
From: ve6eei@ve6eei.ampr.ab.ca (Evan E. Idler, Edmonton, AB [192.75.200.5])
Subject: 9600 Baud Packet Radio Handbook
To: tcp-group@ucsd.edu
I'm sorry if this is the wrong list to submit this to, but since I posted
to the list that I a copy of this 9600 baud packet radio handbook, I have
received over 120 requests for it. Trying to send a copy of this message
to everybody from my station has caused a problem, I have knocked over the
the local mail server for the local uhf packet lan twice, not the nos switch
either, his unix box. So I am posting it the the list in the hope that it
has a better chance of getting it out, and reducing the local load. again
sorry. (ps: I only responded to the first 45 message or so).
Also, if somebody wants to post this to rec.radio.amateur.packet go ahead.
--------------------------------cut here-------------------------------------
*************************
9600 BAUD PACKET HANDBOOK
*************************
A handbook of helpful information for those
wanting to implement K9NG/G3RUH format packet
version 1.1a
11/19/91
by Mike Curtis wd6ehr
7921 Wilkinson Avenue
North Hollywood CA 91605-2210
(818) 765-2857
wd6ehr@n6yn.#socal.ca.usa
internet wd6ehr.ampr.org!wd6ehr@puffin.UUCP
c 1991 by Mike Curtis, except as otherwise noted
permission to copy in whole and/or in part for non-commercial purposes is
given provided that proper credit is given and context is maintained.
CONTENTS
1 9600 BAUD PACKET - WHY?
1.1 DEFINING PACKET RADIO'S SHORTCOMINGS
1.2 THE CURE
2 WHAT DOES IT REQUIRE
2.1 MODEM
2.2 TNC
2.3 RADIO
3 HOW 9600 BAUD PACKET IS DONE
3.1 MODEM
3.2 TNC
3.3 RADIO
3.3.1 CRYSTAL CONTROLLED PHASE MODULATED RADIOS
4 MODIFICATIONS
4.1 RADIO MODS
4.1.1 TXA CUTOFF
4.1.2 FT736 MODS
4.1.3 CRYSTAL CONTROLLED RADIO MODS
4.2 TNC MODS
4.3 MODEM MODS
4.3.1 K9NG MODS
4.3.2 G3RUH MODS
4.3.2.1 G3RUH "GARBAGE" MOD
5 9600 BAUD PARAMETERS
6 HELP
1 9600 BAUD PACKET - WHY?
An often heard quote on packet: "My TNC works fine at 1200 baud. Why
bother with 9600? I can only type with 2 fingers."
This is true, but only if we assume the following:
1. you're the only one typing with 2 fingers on "your" channel;
2. typing with 2 fingers is the ultimate goal of packet;
3. what we're presently doing is all we ever want to do, and;
4. packet in fact _is_ working perfectly.
However, this is far from the case. The present packet system is in
desperate need of improvement. Packet is capable of far more than what we
see it doing today.
1.1 DEFINING PACKET RADIO'S SHORTCOMINGS
First, let's analyze the situation:
1. Short hop simplex works well, but only if the hop is a clean, line of sight
path and the channel is not very busy. If you live in L.A., you're already
rolling on the floor with hysterical laughter.
2. NETROM/TheNET/ROSE, and other networking protocols work poorly with multi-
hop 1200 baud trunking.
3. Mail requires days/weeks to reach its destination, IF it ever gets there!
4. Ruling out HF packet (which isn't such a bad idea anyway :-), we're limited
to NETROM over radio paths of a few hundred miles or so.
5. Other areas, like Europe, have far more sophisticated and efficient packet
trunking systems and user access channels that work.
6. Urban packet channels are overcrowded to the extent that many have thrown
in the towel.
1.2 THE CURE
Now let's dream a bit:
NEWS FLASH! WD6EHR's faerie godmother grants Mike several wishes. After
the obvious wishes have been carried out, a slip of the tongue grants us a
super-duper packet system. (HEY!! I wanted a new pair of socks instead! My
old ones are gettin' kinda gamey!!)
When I wake up in the afternoon, I work FR0CK in France, TR0PIC in Gabon,
L0RRY (Moe) and CU2LY (Joe) (and SH3MP breaks into our roundtable, too), doing
all of this via our high-speed packet multi-megabit world-wide trunking system.
I receive packet mail at my station within seconds of its being posted. We
have conferences with 50 to 100 packeteers on a single 2 meter frequency. Wow,
are my eyes buggin' out! A lot of us are involuntarily learning to speed read!
Todays TIMES headline: EVELYN WOOD DECLARES BANKRUPTCY!
Large files are being transferred between local stations, and are coming in
via the high speed trunk. I decide to get a copy of the newest PD version of
"Super Italian Brothers", which was just finished 30 minutes ago in Japan, so
I connect to our _L_O_C_A_L_ fileserver (he got it automagically off the
master trunk) and download a copy of this 400K file. This takes me all of
10 minutes on our 9600 baud end user channel, while I chat with a few of the
locals (W1MPY in Baastin, Mass; and K0OKY in Dayton, OH) on the conference
bridge. While in QSO, I open another session and look up these guys in the
central nameserver data base, and find that W1MPY used to be a shipmate of
Popeye Doyle, went to school with Dan Quayle, and was originally licensed
in the '60's as H1PPY.
I want to use my little T-1000 laptop XT to do some super-autoCAD (which
requires a full blown 486), so I remote execute on another machine via high
speed packet, and receive the results on my printer.
-=-
Packet has capabilities far beyond simple text applications, such as file
transfer, remote execution (allowing you to use my computer to run software,
and then send the results back to yours), nameservers (callbook on a CD is an
example of this), remote printing, and even linking several smaller computers
to undertake a much larger task than any of these would be capable of alone.
-=-
What would make all of this possible? Higher speed packet. A 10 megabit
world-wide trunking system would tie all the metropolitan areas together, and
these would be served by metropolitan area networks, with efficient 2 meter
9600 baud local access channels. (and higher speed, i.e. 56 kB, on higher
frequencies.)
Am I dreaming? Too many brewski's? Not at all - this is all done using
EXISTING, INEXPENSIVE technology! We don't need any magic - just a small fire
under certain easy chairs - YOURS! And do you know who I'm talking about? All
of you who think I'm talking about someone else! Yes - with POPULAR support,
this isn't just possible - it's easily accomplished!
2 meters is a logical place for end users. The band is amateur-only and is
one of our most consistent and predictable bands. 9600 baud packet is a
"natural". It is "top speed" on 2 meters. It's a lot more efficient than
1200 baud, and therefore a much better use of our precious radio spectrum.
Being FSK, it requires slightly LESS bandwidth than 1200 baud AFSK packet, or
voice, in spite of its greater baud rate.
We're going to have 9600 baud elsewhere, of course; but many feel that
two meters should be the primary thrust for end user 9600 baud packet.
2 WHAT DOES IT REQUIRE
Alright, Mike - I'm sold! What do I need?
2.1 MODEM
9600 baud packet requires a modem. The 2 most common varieties are the
k9ng and g3ruh, but DSP modems will also do k9ng-protocol 9600 baud. Due to
the high cost of DSP modems, we will limit our discussion here to g3ruh and
k9ng modems.
There are 2 flavors of 9600 baud modem: k9ng and g3ruh. Both are compatible
and will work with the same TNC's.
The g3ruh is a very nice 9600 modem. It works with all radios we've tried
so far. It's full-duplex capable, and has a lot of test points.
The k9ng is a low cost means of getting into 9600 baud. It works with a lot
of radios, but is a little less forgiving of group delay, a form of phase
distortion inherent in filters when approaching passband edges. Voice
tolerates phase delays; data doesn't. If necessary, this can be minimized
by widening the receive filter, by reducing C-13 (4000 pf) and C-16 (2000 pf)
to half value (2000 and 1000 respectively).
The Kantronics D-410 radio has a data slicer, and has been tested
successfully with raw data (without a modem). However, this configuration is
not compatible with other formats, such as k9ng/g3ruh, but could certainly be
used in a point to point service, such as trunking.
2.2 TNC
Most TNC's are capable of 9600 baud. Notable exceptions are the Kantronics
KAM/KPC line. (The Data Engine will do 9600 baud and much higher) If your TNC
has a "9600 baud _radio_" option or setting (as opposed to 9600 baud RS-232),
it will likely work with k9ng/g3ruh modems.
2.3 RADIO
You can _N_O_T_ use the radios microphone and speaker jacks for k9ng or
g3ruh format 9600 baud packet. PERIOD! So don't ask!
Why, you ask? (wise guy...) Well, the normal receiver signal path is
designed for voice. Data doesn't make it through. The transmitter microphone
and receiver "speaker" audio is pre-emphasized and de-emphasized. This boosts
and cuts higher audio frequencies, and helps with voice and music. HOWEVER,
like all filters, it also SHIFTS the PHASE, which is verboten with data. Why?
(Hoo boy! You shore ask a lotta ferschlugginner questions!) Your former
digital 1 in the 112th position in the wave train is now delayed to where the
113th position _should_ be, etc., and your data is corrupt! (Hey, I didn't
know data could be bribed :-) (How much does it cost to bribe binary data?
2 bits, of course.)
Besides, both of these 9600 baud modems use "FSK" (shifts between 2 RF
frequencies, id est 145.009850 and 145.010150 MHz for a nominal operating
frequency of 145.01), whereas Bell 202 1200 baud AFSK modems, like your TNC
has, uses 1200 and 2200 Hz AUDIO tones FM'd onto a carrier.
Translated into simple English, this means you need direct connection to
the FM modulator varactor and FM detector.
3 HOW 9600 BAUD PACKET IS DONE
With mirrors, of course :-)
3.1 MODEM
The PacComm NB96 g3ruh modem board plugs inside many TNC,s, such as TNC2
clones (MFJ 1270B, etc). There is a special modem available for the MFJ
1278T (and maybe it'll work with other MFJ's, too???), from MFJ. It takes
the place of the 2400 baud modem.
The k9ng modem kit is cheaper than the g3ruh modem, but is a little fussier
about receivers. If the radio you want to use has a pretty broad receiver
passband, it'll work almost as well as the g3ruh. If the receiver is tight,
the k9ng will be _very_ noticeably poorer. However, this can be somewhat
ameliorated by widening the k9ng's receive filter, as detailed below.
If you need to externally mount your modem and use a ribbon cable, mount
the modem header on the opposite side of the PCB, or use a second short
ribbon cable. Ribbon cables "flop" the pins, i.e.:
1 3 5 7 9 ___________________________ 2 4 6 8 10
2 4 6 8 10 1 3 5 7 9
By placing the connector on top rather than underneath, the flop is reversed.
Normally, you'll want to use the TNC's keying circuit. With the g3ruh,
you have no choice.
3.2 TNC
PacComm, Kantronics, Gracillis, MFJ and probably others have TNC's with
9600 baud G3RUH modems built in. Check the ham mags, call the manufacturers,
or contact your local dealer for information.
Many of us will take the route of installing our own modems. These may
often be installed internally. Sometimes it may be necessary or desireable
to install these externally.
As with all RF environment installations, shielding is important. If an
external box is desired, it really should be a metal one. Shielded cable
to the radio is mandatory - it will not work without it. Some kind of RFI-
proofing of the modem disconnect cable is needed as well. This should be
kept as short and unexposed as possible.
The G3RUH modem requires you to use the TNC's keying circuitry, and this is
recommended for the k9ng as well. If you do this, don't cut the PTT line on
the modem disconnect.
3.3 RADIO
Many modern rigs are true FM, and it's very simple to add a 9600 baud port.
You need only a couple of internal connections and decoupling components to
bring out the "raw" transceiver: the direct detector output and direct FM
modulator input.
Most modern rigs use receiver chips, such as TA7761F/P, LA5006M, LC7532M,
TK10420, TK10424, MC3357P, and others. Note: ALL of the chips mentioned here
use pin 9 for the detector output. Others may or may not, so check first!
Transmit "audio" is injected through a 5 to 10 uF non-polarized capacitor
through a 5K resistor into the modulator. This is typically a varactor diode
in a transmit oscillator stage, and is pretty simple to find, by simply
tracing forward from the microphone. If this is "over your head", see the
free offer at the end of this manual.
3.3.1 CRYSTAL CONTROLLED PHASE MODULATED RADIOS
We have found that synthesized, true FM multimode rigs using varactor
modulation in a crystal oscillator stage tend to work best. They tend to have
a tad wider IF filter (i.e. CFW455E) and pass data with less distortion. Most
synthesized rigs can be made to work, most with extremely simple mods.
However, if your rig is crystal controlled, it can be made to work. If
it's a true FM rig, it's simply a matter of connecting directly to the FM
modulator. This will always be in a crystal oscillator stage.
4 MODIFICATIONS
There are some 9600 baud ready radios, like the TEKK KS-900, Kantronics
DVR 2-2 (not recommended), and D410, but most of us will be using our existing
radios for 9600 baud packet. Here are some specific "mods" and tips.
Radios known to be used at 9600:
Alinco: DR-1200 DataRadio, ALR-72, ALR 709; Kantronics DVR 2-2 Data Radio;
Icom IC series: 25,38,228,271,290,471; Kenwood TR series: 7500, 7700;
TM series: 211,212,221,231,431, TS series: 700 and 770
Standard C58, C140; Yaesu FT series: 212,221,230
4.1 RADIO
4.1.1 TEKK KS-900
For the TEKK KS-900, a TXAudio attenuator is necessary to swamp the modem's
4 volts peak to peak down to the 50 mV range.
This is simply a 470 ohm resistor in series, and a 39 ohm resistor across
the TEKK's transmit input and ground.
4.1.2 OTHER RIGS
It's almost embarassing to call these "mods". We're only bringing out
terminations of existing signals.
These mods are non-destructive unless you QSLF (solder with your left
foot :-) - your rig still does whatever it did before.
Icom IC290H/V: RXA may be obtained at IC12, pin 9, on the main board;
TXA may be injected at D-3 cathode on the main board (This one is my
personal 2 meter 9600 rig, and is a top performer!)
Icom IC28A/E/H : RXA may be obtained at IC1, pin 9, on the RF unit;
TXA may be injected at R-45, at the end NOT connected to trimpot R-100
Icom IC3200A/E: RXA may be obtained at IC1 pin 9 (main board) - this is a
common receiver chip for both bands; TXA may be injected at D3 cathode (VHF)
and D1 cathode (UHF).
Kenwood TM221, TM321A, TM421: RXA may be obtained at IC1, pin 9 (IF board);
TXA may be injected at connection #7 on the VCO assembly on the TX/RX unit.
TR751: RXA may be obtained at IC2,pin 9 on the RX unit;
TXA may be injected at D21 cathode on RX unit.
Use the following circuit to couple the modem to the radio.
MODEM RADIO
5 - 10 MF non-polarized
RXA ----||----------------------------- RXA
5 - 10 MF non-polarized
TXA ----||------o-------o---/\/\/\----- TXA
| | 10K (approx - adjust for 3 KHz dev
| \ with modem's TXA pot about 75%)
.001 === / 500 ohms
| \
| /
| |
_|_ _|_
//// ////
4.1.1 TXA CUTOFF
If you want to leave your 9600 connected and use the rig for other stuff,
use the following relay circuit:
+ 12 VDC----------------o o--->|<------------- Radio PTT
| | N.O.
_|_ |
| | _|_
|RY1| ////
| |
|___| o--->|<------------ Radio TXA
| | N.O.
TNC PTT ----------------o |
|
Modem TXA --------------------o
RY1 is a double pole 12 volt relay. Use the normally open contacts
This removes the modems TXAudio line from the radio's modulator when you're
not keying from the 9600 baud TNC. If you're using the same TNC for 1200 and
9600, make sure you remove the PTT signal from the relay! Otherwise you'll
pick up a nice 4800 Hz "tone" from the 9600 band modem.
4.1.2 FT736 MODS
FT736 & 9600 Baud Operation
---------------------------
by James Miller G3RUH
These notes tell you where to get FM RX audio direct from the
discriminator, and where to modulate the FM TX varactor directly. These
mods are non-destructive and take no more than a few minutes. The signals
bypass the "DATA SOCKET" for high grade FM operations.
The RX mod is suitable for:
* UOSAT-D 9600 baud downlink and terrestrial links
* 1200 baud AFSK/FM Standard Packet - BUT IT'S UNSQUELCHED.
The TX mod is suitable for:
* FO-20/PACSAT uplink (1200 bps Manchester FM)
* UOSAT-D 9600 baud uplink direct FSK and terrestrial links
* 1200 baud AFSK/FM Standard Packet.
---****---
FT736 - FM Direct from Discriminator
-------------------------------------
Detected FM direct from the receiver discriminator is available from the
RX UNIT at the junction of R91 and C83. These components are shown in the
top right-hand corner of the schematic.
Proceed thus:
1. Disconnect FT736 from the mains electricity. (Safety).
2. Remove top cover only.
3. RX Unit is the vertical module on the left.
4. Locate R91 which is about 25mm from the top, 50mm from the radio rear.
the resistor is "on-end", and near a couple of glass diodes.
5. Scrape any paint off R91's free end and wet with solder.
6. Your RXaudio lead should be a fine screened cable; connect the inner
to R91, and the outer braid to a ground point (e.g. can of TO09)
7. Route the cable out though any convenient aperture in the case.
8. The discriminator sensitivity (FM Normal) as about 6 kHz/volt.
Important note on 9600 Baud Use
-------------------------------
Most FT736 receivers are fitted with an LFH12-S IF filter for FM. (CF01 at
the top front of the RX Unit). This is a 12 kHz bandwidth filter which is
a little narrow for 9600 bps FSK operation. It is recommended you change
this to 15 kHz or better still for UOSAT-D use, 20 kHz bandwidth which
will allow more tolerance for doppler shift, and give a far better "eye".
Suitable filters are: LFH-15S or CFW455E, and LFH-20S or CFW455D. The
first of these is a Yaesu spare part, and is often already fitted. Try
the standard first and see what happens; these filters have moderate part
to part variations.
FT736 DIRECT VARACTOR FM MODULATION
------------------------------------
Refer to the circuit diagram; inject your TXaudio at the junction of
R32/C29 on the TX Unit. The signal level at this point should be 800 mV
peak-peak, and will give +/- 3 kHz deviation. DO NOT EXCEED THIS LEVEL.
Set Mic Gain to min.
Modulating the FM transmitter this way you get an LF response down to 18
Hz (at which point the associated synthesiser PLL begins to track the
modulation), and an HF response which is flat to some 10 kHz.
Proceed thus:
1. Disconnect FT736 from the mains electricity. (Safety).
2. Remove top cover only.
3. TX Unit is the module flat on the left (not the one tucked down the
side vertically).
4. R32 is just to the left of the rectangular shielded enclosure. The
resistor is "on end". Scrape any paint off the free leg.
5. Your TXaudio lead should be a fine screened cable; connect the inner
to R32, and the outer braid to the adjacent enclosure.
6. Route the cable out though any convenient aperture in the case.
7a. 1200 BAUD G3RUH PSK MODEM: TXAudio of 800 mV pk-pk can be obtained by
adjusting the components C9= 1uf, R3=47k, R5=infinity (i.e. remove).
C10 stays at 10nf (0.01uf).
7b. 9600 BAUD FSK MODEM: Adjust TXAudio level with VR1
Notes compiled by G3RUH @ GB7SPV 1990 Mar 16
4.1.3 CRYSTAL CONTROLLED RADIO MODS
If your crystal-controlled rig is true FM (varactor modulator in an
OSCILLATOR stage), inject TXA through a 5 mF cap into the varactor cathode.
However, a lot of crystal controlled rigs are phase modulated and need a
varactor modulator added to the transmit crystal oscillator.
Use an abrupt junction type, such as the MV2105 (available from Kantronics),
and adjust the capacitance in the crystal circuit to compensate for the
additional C of the varactor. If there are fixed caps, remove or pad them.
If not, change the trimmer to one of a lower minimum value.
You'll need to bias the varactor. I've used the transmit oscillator Vcc
and a 20K trimpot to ground, feeding bias through 2 10 to 47k fixed resistors,
feeding the modem TXA thru a 5 to 10 uF cap to the center junction of these,
and feeding the free end to the cathode of the varactor. The bias needs to
be adjusted for best received eye pattern on a service monitor or receiver.
TRANSMIT MODS
Transmit oscillator
+Vcc Modem TXA
o o
| |
1 |
0 |
0 |
K === 5 uF non-polarized (required for k9ng)
| |
\ 20K | MV2105 4-20 pF
/ <----- 47K ---o---- 47K ------o-------o----- to TXCO crystal
\ | | | ^
/ | | |/
\ === .001 === ===
/ | /_\ /|
| | | |
o---------------o---------------o-------o----- to TXCO ground
_|_
////
Modifying the IC22A for 9600 baud operation
by Mike Curtis, wd6ehr and Dave Shalita, w6mik
This is one of the more difficult rigs to modify - most are even simpler!
This mod will make your IC22A into a dedicated 9600 baud packet radio.
Components with * are added to the crystal board.
Remove the trimmer capacitor for the transmit crystal socket you'll be
using for 9600 baud. Replace with the above circuit. The 4-20 pF trimcap
should be a good quality ceramic or other low-drift trimmer. (Sorry - Radio
Shack doesn't have anything suitable.)
Connect 2 10K resistors to C-53 (both sides) and tie the other ends
together. This junction is where you'll pick off your RXA.
Turn R-67 (dev control next to P-1 and P-2) completely counterclockwise.
This kills signals that may get into the phase modulator.
Using a service monitor, or oscilloscope connected to the detector of a
receiver, adjust the varactor bias for the best eye pattern.
Alternate bias adjustment:
Use the k9ng's 4800 Hz "idle" tone to adjust your modulator for best linearity.
Using a service monitor, or a receiver with a fairly wide passband, adjust
varactor bias for the "best" sine wave. Thanks to Brian Kantor wb6cyt for
this tip.
4.2 TNC MODS
Your TNC will work better at 9600 baud if you speed it up. For TNC2
clones, change the Z-80 and Z-80 SIO to 10 MHz types, and change the clock
speed by changing the jumper on JP1. Older ones use the 2 OUTER pins, and
newer ones use the center and (other) outer pin.
4.3 MODEM MODS
Most rigs require a lot less TXA than the modem outputs, and a resistive
swamping network may be needed. For example, the TEKK KS900 wants 50 mV.
On the TEKK KS900/PacComm NB96 combo, I use 470 ohms series, and 39 ohms
across the TEKK's input terminal to ground.
4.3.1 K9NG MODS
The k9ng modem's keying circuit can be omitted if you use the TNC's
existing PTT circuit. If you do this, remember to leave the PTT connections
uncut on the TNC modem disconnect.
The k9ng modem's DCD circuit is terrible, and can be vastly improved by
shorting R-31 and changing C-18 to 0.1 mF.
You may find it helpful to widen the k9ng's receive filter. Change C-13
to 2000 pF and C-16 to 1000 pF (half their present value for 9600 baud).
This will widen the passband, and in the process will minimize group delay.
Use the PTT from the TNC instead of the k9ng modem. This lets you use
the TNC's watchdog timer, and makes things a lot simpler. Make sure to cut
only the following traces between pads on your TNC-2's modem disconnect J4:
1/2 DCD
11/12 transmit clock
13/14 receive clock
17/18 receive data
The TNC-2 manual tells you to cut other traces, but by doing it this way,
you'll be able to use the TNC's PTT circuit. The k9ng's keying circuit, which
doesn't work all that well without modification (it's designed for the
Hamtronics FM-5), may now be omitted from the pcb, if you like. This is most
of the stuff on the lower edge of the pcb.
The g3ruh modem from PacComm already does this.
4.3.2 G3RUH MODS
PacComm NB96 MODS
by Mike Curtis wd6ehr
The PacComm NB96 g3ruh modem has a jumper-selectable "defeat", JPS. When
a jumper is in position here, the modem disconnect is normalled through.
I've installed a DPDT slide switch on the front of my MFJ 1274 to make radio
baud rate changes simple. The first pole is used to make the connection to
JPS.The second pole is used to change the radio baud rate selection normally
made by the rear apron DIP switch.
A quick and dirty DCD LED can be easily added to PacComm's NB96 9600 baud
modem board. Pin 13 on U-10 supplies a DCD signal. Connect a 680 ohm
resistor and LED between this and +5 volts, obtainable on pin 24 of S-1
or S-1a, both 26 pin connector positions on the PCB. Only one is used.
Solder your +5 volt wire into the unused hole of the other. Tack the
other lead to U-10 pin 13, or if you do the "garbage" mod below, to pins
8 and 9 of the 74HC00.
You may also use the DCD LED in your TNC by lifting the cathode of the LED,
inserting a diode in series, tacking a second diode to the LED cathode, and
running the cathode of this to modem U-13 pin 10.
4.3.2.1 G3RUH "GARBAGE" MOD
by Steve King kd7ro
Gets rid of random garbage "calls" in MHeard
(edited)
Here is the modification I made to my PAC-COMM NB-9600 modem. This mod got
rid of all the garbage calls in my mheard list both when using the TNC in
standard mode as well as while using net/nos software packages. This
modification makes sure that the modem will send all zeros to the TNC until
the modems PLL is locked on a signal. This means that the TNC will not be
reading garbage coming in to the UART all the time.
1. Remove socket for U11 (74HC14).
2. Insert the 74HC14 directly into the PC board.
3. Lift all the pins of a 74HC00 except 7, 12 and 14.
4. Bend pins so they are pointing straight out.
5. Cut back the bent pins so the 74HC00 can be piggybacked on the 74HC14.
Without removing the socket on U11, I would not have ben able to slide
the modem and Tiny-2 back into the box (you may not have this problem).
6. Cut the trace from U11 pin 12 to U20 (74HC157) pin 13.
7. Solder the 74HC00 on top of U11 (soldering pins 7, 12 and 14).
8. Wire U10 pin 13 (LM339) to the 74HC00 pins 9 and 10.
9. Wire 74HC00 pin 8 to pin 13.
10. Connect pin 11 of the 74HC00 to pin 1 and 2 of the 74HC00.
11. Connect pin 3 of the 74HC00 to pin 13 of U20 (74HC157).
12. Put a piece of tape over the top of the 74CH00 to insulate from the case.
The DCD signal coming from U10 (LM389) is low true so I invert it using
one of the nand gates (pins 8, 9 and 10). This is used to qualify the
RXD signal from the 74HC14 (pin 12). Pin 11 of the 74HC00 is the RXD signal
(low true) qualified by the DCD signal which is LOCK DETECT. One more
inversion of this signal (74HC00 pins 1, 2 and 3) and I have the qualified
RX DATA signal which is connected to U20 (74HC157) pin 13.
RX DATA is always zero until the PLL is locked to the data. Then RX DATA
will be the true data comming from the unscrambler or zeros if we are not
locked.
Steve King (KD7RO) king@hpdml57.boi.hp.com
Hewlett Packard
Boise, Idaho
5 9600 BAUD PARAMETERS
As you'd expect, the parameters we all know and love at 1200 baud don't
work very well at 9600 baud. These are what we've found work well at 9600.
5.1 AX.25 PARAMETERS
TXDelay between 8 and 15 - set for best throughput
RESPtime 100 mS seems to have better results than 0
FRack 8 seconds on a busy channel; but never less than 5 seconds
PERSIST 128/users; if it's a pretty clean channel, 64 is nice; if it's
busy, guesstimate the average number of users and divide 128
by this number, i.e. 4 users = 128/4 = 32
SLOTTIME 20
MAXFrame If the channel is great, 7; average, 3; rough, 1
RETry 15
CHeck 300 seconds
5.2 TCP/IP PARAMETERS
My 9600 baud interface is called "96"; here are params from my files.
par 96 1 8
par 96 2 64
par 96 3 20
par 96 4 2
ax25 maxframe 3
ax25 paclen 256
ax25 pthresh 64
ax25 retry 15
ax25 t1 8000
ax25 t2 1000
ax25 t3 300000
ax25 t4 900000
mode 96 datagram
ax25 persist 96 256 5 128 15 60
Some of these parameters are specific to pe1chl NET, so don't get an
ulcer if your version barfs on them.
6 HELP
If you have a radio you'd like to use for 9600 baud, but don't know where
to find the "magic points", send me 2 copies of the schematics - one for me,
and one for you (block diagrams are nice but not absolutely required), and
a stamped, addressed return mailer. I'll get out my red "test grading" marker
and mark the points where you'll find raw RXA and TXA.
Some of these mods are tested, and some aren't, but should work fine.
These are non-destructive (yup - you can still use it for whatever it was used
for before), and are generally a simple matter of tacking 2 caps to easily
accessible spots on the PCB, adding the 2 resistors, attaching 2 pieces of
mini shielded cable, and bringing the 2 connections out.
Yours,
_ _ _ __
' ) ) ) / / ) _/_
/ / / o /_ _ / . . __ / o _
/ ' (_<_/ <_(/_ (__/ (_/_/ (_<__<_/_)_
Packet: wd6ehr@n6yn.#soca.ca.usa wd6ehr@wd6ehr.ampr.org [44.16.0.21]
Internet: wd6ehr.ampr.org!wd6ehr@puffin.UUCP Compu$erve 73240,3523
wd6ehr-3 netrom switch wd6ehr-6 conference bridge wd6ehr-8 mbox/info
145.36- 1200/9600 baud duplex repeater <----> 439.025 - both @9600 baud
7921 Wilkinson Avenue; North Hollywood CA USA 91605-2210 (818) 765-2857
--------------------------------cut here--------------------------------------
=======================================================================
Evan E. Idler | Of All The Things I've Lost
ve6eei@ve6eei.ampr.ab.ca | In Life, I Miss My MIND The
Edmonton, Alberta, Canada | Most!!!
Amateur Packet Radio Station VE6EEI [192.75.200.5]
=======================================================================
------------------------------
Date: Sat, 17 Jul 1993 00:41:05 -0500 (CDT)
From: ssampson%sabea-oc.af.mil%UCSD.EDU@Sdsc.BITnet (Mr. Sampson)
Subject: 9600 Experiances
To: TCP-Group%UCSD.EDU@Sdsc.BITnet
------------------------------
Date: Sat, 17 Jul 1993 00:41:05 -0500 (CDT)
From: ssampson%sabea-oc.af.mil%UCSD.EDU@Sdsc.BITnet (Mr. Sampson)
Subject: 9600 Experiances
To: TCP-Group%UCSD.EDU@Sdsc.BITnet
------------------------------
Date: Fri, 30 Jul 1993 15:27:11 PDT
From: PMcAfee.El_Segundo@xerox.com
Subject: 9600 Modems/Radios
To: tcp-group@ucsd.edu
Steve Sampson, N5OWK askes about muRata filters and where to find them.
In my short form catalog no. 63-05 I see listed Newark Electronics, Sterling Electronics
and Time Electronics all in the So West as distributors . The CFW455B that his
D4-10 uses is listed as+/- 15 Khz at the 6 db BW points. This is the widest
they list for this series.
I agree that we should keep this modem discussion going on the tcp-group, I see
no reason to move. We need some good technical stuff here.
Pete kd6hr
kd6hr.el_segundo@xerox.com
------------------------------
Date: Fri, 30 Jul 1993 13:52:08 -0500 (CDT)
From: Mr. Sampson <ssampson@sabea-oc.af.mil>
Subject: 9600 Radios
To: TCP-Group@UCSD.Edu
Evan E. Idler says:
> I have a file I received about a year ago, written by Mike Curtis
I've seen it, and I don't like it. He recommends 5 - 10 uF for a coupling
capacitor to the radio! I don't think he's tried any of his recommendations
because most TNC's already have a coupling capacitor in them, and this value
appears way too high. He also says his Icom 229 (same as my 228) is a top
performer. Too many statements not in line with my findings...
Glenn Elmore says:
> Is there a forum anywhere for discussing this?
I vote we keep it here. Brian said this forum lost it's focus (probably
never had one) then said he was going to shut it down (someone else started
a listserver and I think it hurt his feelings) so we can probably spend the
next year talking about modems and occassionally refer to their use with
TCP/IP and not even break the 4k Digest length barrier we've had the last
6 months. Personally I like the Digest format rather than a bunch of mail,
and that will get me to subscribe. If this isn't Advanced (greater than
1200 bps connected-mode) Networking, I don't know what is...
> I think we need both a source of wider 455 KHz filters and xtal
> filters.
I called various suppliers and came up empty handed. Who sells these
filters. Everyone I called had me explain it several times and they have
all sorts of radio parts, so there must be little demand for Murata (sp?)
filters.
> It seems like there ought to be a market for a "digital IF
> adapter" which uses a couple of conversions,
Say, this might be the only way to fix this major problem. I think most people
just give up and stick with 1200 or jump to 56k with the better (more
expensive) modem design. I just checked my D4-10 and it uses a CFW455B model
filter. While this radio has an overall good design, they really messed up on
the oscillator design. There's no temperature compensation and it drifts all
over the place. So we can't expect the data industry to design a good radio
for us. Maybe Ramsey can implement the design into their kit line.
---
Steve, N5OWK
------------------------------
Date: Fri, 30 Jul 1993 09:33:25 PDT
From: Mike_Beezley.houstoncssc@xerox.com
Subject: Firmware PK-88 23.AUG.91
To: ik5veq@radio-gw.cnuce.cnr.it
Alex
>> Do you know if exist an e-mail of AEA ??? <<
No, I don't know if AEA is on the Interent or is E-Mail capable.
I looked the the PK88 manual last night and saw that it is capable of HBAUD
upto 19.2K. Guess I never persued it beyond 1200 baud before. I tried on some
of my local nodes and the ones that are 9.6 are FSK not AFSK. Is there anyone
out there on the packet nets doing 9600/19.2K with an AFSK TNC?
I'm not even sure if my Yaesu FT5100 can handle the bandwidth requirement.
73 de N5PWP
__mike
------------------------------
Date: Fri, 30 Jul 93 13:51:15 -0700
From: John_Hays@NeXT.COM (John D. Hays)
Subject: Firmware PK-88 23.AUG.91
To: Mike_Beezley.houstoncssc@xerox.com
Mike,
Here are the CompuServe addresses of several support people, to send them email
from the Internet (remembering acceptable use guidelines) convert the
CompuServe address as follows for WF7A change '76702,1013' to
76702.1013@CompuServe.com --- That's all there is to it...
Richard Stuart WF7A (AEA) 76702,1013
Gary KF7XV (ICOM) 75540,525
Jeff WA4EGT/6 (InterFlex) 72540,75
Stan AA5XO (MFJ) 76206,1763
Gregg N6ZSW (Alinco) 72130,2343
Steve Whitefield (Drake) 70761,322
Norm W2JUP (PacComm) 76576,2003
Jim Van Peursem (Savant) 71574,421
Rick KD2XB (Quantum) 71764,140
73 de KD7UW
John Hays
john_hays@next.com
------------------------------
Date: Fri, 30 Jul 93 11:25:23 +0100
From: agodwin@acorn.co.uk (Adrian Godwin)
Subject: KISS parameter 6
To: tcp-group@ucsd.edu
NOS source code deals with a parameter 6 than can be sent to TNCs,
and traces the value sent as 'hardware'. However, the TNC KISS
code I have (k3mc version 4.0) doesn't implement a parameter 6
- can anyone tell me what it's defined to do ?
-adrian
------------------------------
Date: Fri, 30 Jul 93 12:32:19 PDT
From: cwi@netcom.com (Mike Cheponis)
Subject: KISS parameter 6
To: tcp-group@ucsd.edu
> NOS source code deals with a parameter 6 than can be sent to TNCs,
> and traces the value sent as 'hardware'. However, the TNC KISS
> code I have (k3mc version 4.0) doesn't implement a parameter 6
> - can anyone tell me what it's defined to do ?
>
> -adrian
Adrian, this was intended as an "escape" so that manufacturers could implement
extended h/w control functionality. For example, I think it is used in some
versions to set the port's baud rate to something different from a default
baud rate.
There are no special hardware considerations in the TNC-2, so the command's not
implemented in that version.
-Mike k3mc
------------------------------
Date: Fri, 30 Jul 93 11:43:54 -0700
From: "Dana H. Myers" <dana@fafnir.la.locus.com>
Subject: Micor identification and crystals (was: Micors at 9600 baud)
To: mike.murphree@stpete.honeywell.com, tcp-group@ucsd.edu
> >On Micors, there is a DVP reciever boards. These boards have wider IFs in
> >them, and should be able to work to 24Kb.
>
> I've heard of this from our local Moto surplus guru. Does anyone know
> what the distinquishing marks are for a radio that has the DVP option?
> The only mods that I have seen for the Micors involved completely
> removing the second set of filters and replacing with caps...
A DVP radio will have a model number something like:
T43RXA3200..
||| | |
||| | -- This means PL squelch. DPL is 6, carrier is 1
||| ---- This means DVP. 'RTA' means normal radio.
|| ------ This refers to frequency range. 3 is VHF-Hi, 4 is UHF
| ------- This refers to power level. Bigger # == more power
-------- This means trunk mount. All Micors are trunk mount.
> >The UHF Micors are especially nice for transmit; they use an offset oscillator
> >mixed with the receive rock to generate the transmit frequency. This
> >presents a problem in that you usually need to (a) replace the standard
> >exciter with a "wide-space" exciter or (b) replace the standard exciter
> >rock with a simplex rock to get simplex operation. However, the advantage
> >is that the offset oscillator is the one that is frequency modulated. Once
> >you set the radio up (deviation, etc.) you can change channels without
> >potentionally having to re-tweak the deviation.
>
> Hmmmm.... Mine have separate TX and RX channel elements... Anyone have
> the crystal specs to order new crystals for them??
The VHF Low band and High band radios use RX and TX rocks. The UHF radios
use an offset oscillator.
Order your rocks from JAN Crystals. $11 each, commercial spec, they know
the specs for the particular radio. They may ask you for information
on the channel element when you order; you *do* have channel elements,
right? :-)
Dana
------------------------------
Date: 30 Jul 1993 11:11:32 -0500 (EST)
From: Mike Murphree <mike.murphree@stpete.honeywell.com>
Subject: Micors on 9600
To: tcp-group@ucsd.edu
>> Other radios I've examined, including a crystal controlled HT ( a
>> Clairmont,which looks a lot like a Wilson) and a Motorola Micor, both had
^^^^^^^^^^^^^^
>This is where my interest currently lies.
Mine too, I bought two of these big heavy things with the hopes
of converting them from 9600 use.
>On Micors, there is a DVP reciever boards. These boards have wider IFs in
>them, and should be able to work to 24Kb.
I've heard of this from our local Moto surplus guru. Does anyone know
what the distinquishing marks are for a radio that has the DVP option?
The only mods that I have seen for the Micors involved completely
removing the second set of filters and replacing with caps...
>The UHF Micors are especially nice for transmit; they use an offset oscillator
>mixed with the receive rock to generate the transmit frequency. This
>presents a problem in that you usually need to (a) replace the standard
>exciter with a "wide-space" exciter or (b) replace the standard exciter
>rock with a simplex rock to get simplex operation. However, the advantage
>is that the offset oscillator is the one that is frequency modulated. Once
>you set the radio up (deviation, etc.) you can change channels without
>potentionally having to re-tweak the deviation.
Hmmmm.... Mine have separate TX and RX channel elements... Anyone have
the crystal specs to order new crystals for them??
******************************************************
* 73 de Mike, N4CNW@W4DPH.#TPA.FL.USA.NA *
* Amprnet: n4cnw@n4cnw.ampr.org [44.98.0.151] *
* Internet: mike.murphree@stpete.honeywell.com *
* -------------------------------------------------- *
* "I'd rather have a bottle in front of me, *
* than a frontal labotomy!" *
******************************************************
------------------------------
Date: Fri, 30 Jul 93 12:37:28 -0500
From: sbrown@charon.dseg.ti.com (Steve Brown)
Subject: Micors on 9600
To: mike.murphree@stpete.honeywell.com
> >On Micors, there is a DVP reciever boards. These boards have wider IFs in
> >them, and should be able to work to 24Kb.
>
> I've heard of this from our local Moto surplus guru. Does anyone know
> what the distinquishing marks are for a radio that has the DVP option?
> The only mods that I have seen for the Micors involved completely
> removing the second set of filters and replacing with caps...
I have the MICOR service manual. I'll look when I get home. It'll
help if I know what I'm looking for. Is DVP an acronym? I don't
remember anything like that.
> Hmmmm.... Mine have separate TX and RX channel elements... Anyone have
> the crystal specs to order new crystals for them??
JAN Crystals in Ft. Lauderdale (I think) knows how to cut crystals for
MICORs. I have had two sets made there. They charge $11 for each
crystal. I'll send you their number if you need it. You can usually
find the number in any on the ham magazines. (I have no connection
with JAN Crystals other than as a customer.)
*********************************************
| Steve Brown, WD5HCY | |
| sbrown@charon.dseg.ti.com | Simplicate |
| wd5hcy@wd5hcy.ampr.org | and add |
| [44.28.0.61] | lightness. |
| wd5hcy@kf5mg.#dfw.tx.usa.na | |
*********************************************
------------------------------
Date: Fri, 30 Jul 1993 15:50:39 -0500 (CDT)
From: gerry@cs.tamu.edu (Gerald J Creager)
Subject: Micors on 9600
To: mike.murphree@stpete.honeywell.com (Mike Murphree)
The VHF micors have 1 xtal for transmit and 1 for receive. The UHF micors are
one xtal per channel.
73, gerry
------------------------------
Date: Fri, 30 Jul 93 13:50:23 -0700
From: "Dana H. Myers" <dana@fafnir.la.locus.com>
Subject: Micors on 9600
To: mike.murphree@stpete.honeywell.com, sbrown@charon.dseg.ti.com
Steve Brown, WD5HCY wrote:
>
> I have the MICOR service manual. I'll look when I get home. It'll
> help if I know what I'm looking for. Is DVP an acronym? I don't
> remember anything like that.
DVP means "Digital Voice Protection". DVP converts the voice input to
a delta-modulation digital sequence, which is encoded in a handful of
CMOS chips using a programmable seed. You need a special DVP Micor
service manual.
Later DVP technologies include DES encyption.
DVP Micors are somewhat special on VHF, since the normal VHF Micors
are phase modulated. However, much like the requirement for direct-FM
on 9600 baud, DVP radios also were direct-FM. On the VHF Micors, this
is usually accomplished with a "four pin channel element", these are
also used in Micors equipped with DPL (digital private line). The
modulation is applied to the channel element to shift the crystal
frequency, rather than using the serrasoid (phase) modulator.
> > Hmmmm.... Mine have separate TX and RX channel elements... Anyone have
> > the crystal specs to order new crystals for them??
>
> JAN Crystals in Ft. Lauderdale (I think) knows how to cut crystals for
> MICORs. I have had two sets made there. They charge $11 for each
> crystal. I'll send you their number if you need it. You can usually
> find the number in any on the ham magazines. (I have no connection
> with JAN Crystals other than as a customer.)
I have nothing but praise for JAN. 1-800-JAN-XTAL, 8a-5p Eastern, M-Thu.
------------------------------
Date: Fri, 30 Jul 93 14:05:02 -0700
From: karn@qualcomm.com (Phil Karn)
Subject: Micors on 9600
To: sbrown@charon.dseg.ti.com
>I have the MICOR service manual. I'll look when I get home. It'll
>help if I know what I'm looking for. Is DVP an acronym? I don't
>remember anything like that.
DVP = "Digital Voice Privacy". This is what the name implies - a radio
that digitizes voice, encrypts and transmits it. The radio itself
becomes a data modem, so it makes sense that DVP-compatible radios should
be (more) suitable for packet radio than conventional voice radios.
Anybody out there with more detailed knowledge about Motorola DVP - data
rates, modulation methods, etc?
Phil
------------------------------
Date: Sun, 18 Jul 93 1:24:24 CDT
From: ortmann%plains.NoDak.edu%UCSD.EDU@Sdsc.BITnet (Daniel Ortmann)
Subject: NOS on MS-Windows?
To: tcp-group%UCSD.EDU@Sdsc.BITnet (tcp group)
------------------------------
Date: Sun, 18 Jul 93 1:24:24 CDT
From: ortmann%plains.NoDak.edu%UCSD.EDU@Sdsc.BITnet (Daniel Ortmann)
Subject: NOS on MS-Windows?
To: tcp-group%UCSD.EDU@Sdsc.BITnet (tcp group)
------------------------------
Date: Fri, 30 Jul 1993 22:17:28 -0600
From: ve6eei@ve6eei.ampr.ab.ca (Evan E. Idler, Edmonton, AB [192.75.200.5])
Subject: source of wider if filters.
To: tcp-group@UCSD.EDU
I got the filters for two ft-736's that I modified from Yaesu's parts
department. They have both the 15 and 20 kc filters that are mentioned
in the article. They seemed to help quit a bit.
73
Evan
=======================================================================
Evan E. Idler | Of All The Things I've Lost
ve6eei@ve6eei.ampr.ab.ca | In Life, I Miss My MIND The
Edmonton, Alberta, Canada | Most!!!
Amateur Packet Radio Station VE6EEI [192.75.200.5]
=======================================================================
------------------------------
Date: Fri, 30 Jul 93 14:48:59 +0100
From: agodwin@acorn.co.uk (Adrian Godwin)
Subject: TCP-Group Digest V93 #194
To: tcp-group@ucsd.edu
Jeffrey Austen <JRA1854@tntech.edu> wrote :
>
> I am interested in discussing the establishment of a standard
> "modem"/digital-hardware interface so that we could get the "modem" into
> the radio case, where it belongs, and eliminate all this fussing with
> getting the right levels and waveforms etc. between different boxes.
>
> Jeff, k9ja
> jra1854@tntech.edu
>
Dave Hough, G4WRW (dave@llondel.demon.co.uk) was trying to set some
standards for this in the UK. I don't think he's published anything
yet, but is collecting suggestions.
I agree that the modem should be in the radio case for systems that
use something other than narrowband FM voice channels, but there's
also some advantage in defining an audio interface for connecting
external modems to ordinary radios. Unfortunately, although this
is by far the biggest problem at the moment, I don't think that
such a standard would achieve much market penetration before it
became completely redundant. Or I hope it wouldn't :-).
For the digital interface, I'd like to see differential RS-422 with
clocks supplied by the modem, and RTS/CTS/DCD.
Power control / SSI is desirable, but might have to be analogue to
avoid unnecessary complexity in the modem.
Anybody got any better ideas ?
-adrian
------------------------------
Date: Tue, 27 Jul 93 04:15:21 PST
From: Postmaster@versant.com
Subject: Undelivered mail
To: POSTMAST%CSPGUK11.BITNET@Sdsc.Edu
----------------------------Original message----------------------------
Returned Mail: User dgilmour@ccmail.versant.com Unknown
*** Returned Mail Message Follows: ***
------------------------------
Date: Thu, 29 Jul 93 07:29:08 PST
From: Postmaster@versant.com
Subject: Undelivered mail
To: POSTMAST%CSPGUK11.BITNET@Sdsc.Edu
----------------------------Original message----------------------------
Returned Mail: User dgilmour@ccmail.versant.com Unknown
*** Returned Mail Message Follows: ***
------------------------------
Date: Thu, 29 Jul 93 08:38:51 PST
From: Postmaster@versant.com
Subject: Undelivered mail
To: POSTMAST%CSPGUK11.BITNET@Sdsc.Edu
----------------------------Original message----------------------------
Returned Mail: User dgilmour@ccmail.versant.com Unknown
*** Returned Mail Message Follows: ***
------------------------------
Date: Tue, 27 Jul 93 04:36:01 PST
From: Postmaster@versant.com
Subject: Undelivered mail
To: POSTMAST%CSPGUK11.BITNET@Sdsc.Edu
----------------------------Original message----------------------------
Returned Mail: User dgilmour@ccmail.versant.com Unknown
*** Returned Mail Message Follows: ***
------------------------------
End of TCP-Group Digest V93 #195
******************************
******************************