Re: [digitalradio] Amp for sale on Ebay

[Robert Chudek - K0RC]

I wonder if it covers the 30-meter band?

73 de Bob - KØRC in MN


  - Original Message - 
  From: "John Becker, WØJAB" 
  To: digitalradio@yahoogroups.com 
  Sent: Friday, April 11, 2008 12:57 PM
  Subject: [digitalradio] Amp for sale on Ebay





  Item #  170209454193





   <<97b7cdc.JPG>>

Re: [digitalradio] Re: RTTY Standard

[Robert Chudek - K0RC]

I know the AEA PK-232 used 200 Hz, as well as the Heathkit HK-232, but the 
Kantronics KAM series all used 170 Hz shift. That was the reason I switched 
from the AEA to the KAM products.

What Kantronics models used 200 Hz shift?

73 de Bob - KØRC in MN


  - Original Message - 
  From: Jose A. Amador 
  To: digitalradio@yahoogroups.com 
  Sent: Tuesday, February 12, 2008 8:35 AM
  Subject: Re: [digitalradio] Re: RTTY Standard



  Kantronics and AEA too.

  I have a Communications Quarterly issue from the mid 90's somewhere here 
  in which the author modifies its filters for 170 Hz and describes a 
  great improvement for AMTOR...but also becomes almost useless for 300 
  baud packet.

  AM7910 modems have 200 Hz shift.

  Jose, CO2JA

  ---

  Brad wrote:
  > --- In digitalradio@yahoogroups.com, "Robert Chudek - K0RC" <[EMAIL 
PROTECTED]>
  > wrote:
  >> For amateur radio stations, 45.45 bauds and 170 Hz shift.
  >>
  > 
  > 
  > Don't be surprised to find some 200Hz shift there too. Kantronics or
  > someone used it as their standard, but generally, 170Hz machines had
  > no problem decoding it.
  > 
  > Brad VK2QQ

  __

  Participe en Universidad 2008.
  11 al 15 de febrero del 2008.
  Palacio de las Convenciones, Ciudad de la Habana, Cuba
  http://www.universidad2008.cu


   

Re: [digitalradio] Re: Operating FSK RTTY in a contest ?

[Robert Chudek - K0RC]

I started my RTTY career using 2125 and 2975 tones... until those young brats 
started pushing the envelope (or should I say, squeezing the envelope) with 
those 170 Hz tones... things were much simpler in those good ole days... your 
betcha... the smell of a well oiled machine, a whiff of ozone from the 
commutator, polar relays! (hey remember them?), and the quiet roar of all that 
machinery pounding out your CQ's... It was great... well, except for two 
things... having your platen pounded to death at the right margin, and coming 
home to find a half roll of paper behind the machine because some smart-a** 
thought it was cute to auto start your machine and feed it 15 minutes of line 
feeds. Yep, the good ole days...  ! ! ! 

73 de Bob - KØRC in MN



  - Original Message - 
  From: "John Becker, WØJAB" 
  To: digitalradio@yahoogroups.com 
  Sent: Monday, February 11, 2008 7:59 PM
  Subject: Re: [digitalradio] Re: Operating FSK RTTY in a contest ?


  It once was very easy to copy RTTY when *everyone* used
  2125 and 2295 Hz tones. Then came the 200 Hz shift TNC's
  and now you have sound cards and people that are up side
  down with their tones. And please don't get me started on 
  no CR/LF after 70 or charters.



   

Re: [digitalradio] Re: Operating FSK RTTY in a contest ?

[Robert Chudek - K0RC]

Andy,

Regarding matching the RTTY tones... matching a tone is difficult for some 
people and easy for others. For example, some people sing off key! Were you 
good at matching the note of the pitch pipe in music class?  :-)

You said some RTTY signals did not sound the same as yours. I heard this as 
well, and one was so blatant I had to look at my scope! The reason for this 
dissimilar sound is because some fellows overdrive their transmitter audio 
input when using AFSK. This generates distortion, harmonics and secondary 
signals. I hear this during every RTTY contest and last weekend was no 
exception. A bad soundcard or driver could be a potential problem as well, but 
not as likely as excessive mic gain.

If a RTTY signal is generated by AFSK and the audio is not pure, it will sound 
different from good 2125 and 2295 tones. It's the same principle that a middle 
C note on a violin sounds different than the same note on a clarinet. Both 
instruments produce the same fundamental frequency, but each has its unique 
signature of harmonics and overtones that allow you to easily distinguish 
between them.

So now you know why a lot of RTTY operators say this mode is "music to their 
ears"! But why are they called "green keys"? A piano is black and white.

73 de Bob - KØRC in MN



  - Original Message - 
  From: Andrew O'Brien 
  To: digitalradio@yahoogroups.com 
  Sent: Monday, February 11, 2008 7:26 PM
  Subject: [digitalradio] Re: Operating FSK RTTY in a contest ?


  -Bob, thanks for your helpful advice. I am interested in your
  comments about matching the RTTY tones, his and mine. A few times
  over the weekend I did note that my tones did not sound as musical as
  the tones I was decoding. Looks like I need more practice with RTTY FSK.

  Andy.

  -- In digitalradio@yahoogroups.com, "Robert Chudek - K0RC" <[EMAIL PROTECTED]>
  wrote:
  >
  > Andy,
  > 
  > When using FSK and the MMTTY/N1MM software, the NET button has no
  effect. That button is used only when your setup is configured for
  AFSK mode.
  > 
  > Regarding the AFC button, you may or may not want to have that
  turned on. It depends on how you are operating. When you are searching
  for stations to work, you would have the AFC turned OFF. You can think
  of this as locking the MMTTY decoder tones to 2125 and 2295 Hz. You
  have the right idea in your message.
  > 
  > If you are sitting on a frequency, calling CQ, and having stations
  come back to you, then you may want the AFC turned ON. What this does
  is to release the MMTTY decoder so it can Automatically Frequency
  Correct (AFC) its internal filters to capture a station that may be
  calling you that is off frequency.
  > 
  > You can see how this works by starting with AFC turned off. Tune to
  a DX station that is calling CQ. Get your waterfall, bandscope, and XY
  display lined up. Note the "Mark" window will say 2125. Now turn the
  AFC on. Watch this window as stations come on frequency and call the
  DX. Some stations may be exactly on frequency, while others will be
  off. For the stations that are off frequency, you will see MMTTY
  automatically adjust that "Mark" window number, up or down, depending
  whether the caller is low or high from zero beat with the DX. This
  number "jumps around" a bit, but you can get a close approximation how
  far off of zero beat a caller is by subtracting 2125 from the number
  that appears in this window. If it reads 2025 you know they are 100 Hz
  from zero beat.
  > 
  > To ensure you are "on frequency" for a caller, the first thing is to
  make sure you are using the monitor to listen to your own TX signal.
  If you're musically inclined, you can simply match the pitch of the
  station you are calling to the pitch of your monitor. Beyond that, the
  MMTTY audio bandscope is probably the most accurate tool. You can also
  enable the FIR demodulator. Click the "Type" button and look above the
  Mark window. There are 3 demodulators that you cycle through by
  clicking the button. The FIR demodulator gives you a very sharp +
  symbol on the XY scope. And of course double check your TS-2000 menu
  settings to make sure your FSK is set for 170 Hz and the standard tone
  pairs of 2125 and 2295 Hz. I don't have a TS-2000 manual, but Kenwood
  is pretty good about documenting the RTTY stuff so this information
  should be in there somewhere.
  > 
  > In two weeks there will be the NCJ RTTY NA QSO Party, a 10-hour
  event that is a lot of fun. Check it out here: 
  http://www.ncjweb.com/naqprules.php
  > 
  > 73 de Bob - KØRC in MN
  > 
  > 
  > 
  > - Original Message - 
  > From: Andrew O'Brien 
  > To: DIGITALRADIO 
  > Sent: Sunday, February 10, 2008 6:39 PM
  > Subject: [digitalradio] Operating FSK RTTY in a contest ?
  > 
  > 
  &

Re: [digitalradio] RTTY Standard

[Robert Chudek - K0RC]

For amateur radio stations, 45.45 bauds and 170 Hz shift.

73 de Bob - KØRC in MN


  - Original Message - 
  From: Walt DuBose 
  To: digitalradio 
  Sent: Monday, February 11, 2008 3:56 PM
  Subject: [digitalradio] RTTY Standard


  What are the current RTTY standards for baud and shift?

  Tnx & 73,

  Walk/K5YFW


   

Re: [digitalradio] Operating FSK RTTY in a contest ?

[Robert Chudek - K0RC]

Andy,

When using FSK and the MMTTY/N1MM software, the NET button has no effect. That 
button is used only when your setup is configured for AFSK mode.

Regarding the AFC button, you may or may not want to have that turned on. It 
depends on how you are operating. When you are searching for stations to work, 
you would have the AFC turned OFF. You can think of this as locking the MMTTY 
decoder tones to 2125 and 2295 Hz. You have the right idea in your message.

If you are sitting on a frequency, calling CQ, and having stations come back to 
you, then you may want the AFC turned ON. What this does is to release the 
MMTTY decoder so it can Automatically Frequency Correct (AFC) its internal 
filters to capture a station that may be calling you that is off frequency.

You can see how this works by starting with AFC turned off. Tune to a DX 
station that is calling CQ. Get your waterfall, bandscope, and XY display lined 
up. Note the "Mark" window will say 2125. Now turn the AFC on. Watch this 
window as stations come on frequency and call the DX. Some stations may be 
exactly on frequency, while others will be off. For the stations that are off 
frequency, you will see MMTTY automatically adjust that "Mark" window number, 
up or down, depending whether the caller is low or high from zero beat with the 
DX. This number "jumps around" a bit, but you can get a close approximation how 
far off of zero beat a caller is by subtracting 2125 from the number that 
appears in this window. If it reads 2025 you know they are 100 Hz from zero 
beat.

To ensure you are "on frequency" for a caller, the first thing is to make sure 
you are using the monitor to listen to your own TX signal. If you're musically 
inclined, you can simply match the pitch of the station you are calling to the 
pitch of your monitor. Beyond that, the MMTTY audio bandscope is probably the 
most accurate tool. You can also enable the FIR demodulator. Click the "Type" 
button and look above the Mark window. There are 3 demodulators that you cycle 
through by clicking the button. The FIR demodulator gives you a very sharp + 
symbol on the XY scope. And of course double check your TS-2000 menu settings 
to make sure your FSK is set for 170 Hz and the standard tone pairs of 2125 and 
2295 Hz. I don't have a TS-2000 manual, but Kenwood is pretty good about 
documenting the RTTY stuff so this information should be in there somewhere.

In two weeks there will be the NCJ RTTY NA QSO Party, a 10-hour event that is a 
lot of fun. Check it out here:  http://www.ncjweb.com/naqprules.php

73 de Bob - KØRC in MN



  - Original Message - 
  From: Andrew O'Brien 
  To: DIGITALRADIO 
  Sent: Sunday, February 10, 2008 6:39 PM
  Subject: [digitalradio] Operating FSK RTTY in a contest ?


  By the way, my TS2000 is one year old today, one year at my shack.

  With the TS-2000 being my first rig that could do FSK RTTY, I have not
  got around to much RTTY contesting in the past year. I dabbled a
  little today in the CQ RTTY contest, my old RTTY contesting used to be
  exclusively AFSK sound card RTTY. I have mainly used Winwarbler for
  FSK with the TS-2000, but in the RTTY contest this weekend I used
  N1MM Logger and the MMTTY Engine. I had a few odd things happen, 4-5
  times I could have sworn that the station I was working moved up the
  dial a few Hz. I was in hunt and pounce mode. I tuned the station,
  decoded him, transmitted, and they answered. A few times in the QSOs
  I noticed them 100-200 Hz from where they started . One station that
  this happened to came back to me and said I was "off frequency".
  When operating FSK RTTY, is it standard to work with NET and AFC OFF?
  I had both off during the contest, since I assume that with FSK I need
  to transmit exactly where I tuned the station (I used the MMTTY
  spectrum display to tune the station precisely). I wonder if the
  stations that appeared to drift were stations with their AFC "on", and
  something drew them up the band a little ? Maybe I am doing something
  wrong with MMTTY in N1MM? I had MMTTY set for the standard "HAM"
  profile. How does one ensure you are "on frequency" in FSK RTTY ?

  -- 
  Andy K3UK
  www.obriensweb.com
  (QSL via N2RJ)


   

Re: [digitalradio] Re: SSB on 14070

[Robert Chudek - K0RC]

That's an "interesting" frequency to select for the source of voice qrm. I 
wouldn't be so fast to blame VE's or other non-US stations for this increased 
interference. That is the BFO (14070 dial) frequency for virtually every 
transceiver running PSK on 20 meters.

With the proliferation of PSK31 using soundcard technology, my first 
inclination would be some operators do not mute or disable their microphone 
when using AFSK for these modes. 

So now there's a live mic in the shack while they are happily PSKing away. 
Everything is fine until they shout... "HEY MARTHA, WHAT'S FOR DINNER TODAY?"

Instant qrm. 50 years ago the operator knew when his microphone was live and on 
the air!  :-)

73 de Bob - KØRC in MN



  - Original Message - 
  From: Rick 
  To: digitalradio@yahoogroups.com 
  Sent: Thursday, February 07, 2008 8:21 AM
  Subject: Re: [digitalradio] Re: SSB on 14070


  I have been hearing more activity that appears to be illegal voice than 
  I have ever heard in the past 50 years. It is so bad that a number of 
  times I have been hearing voice transmissions that interfere with WWV 
  reception!

  Probably much of the voice activity on the ham bands that are in the 
  U.S. text data portions of the bands are due to operators in other 
  countries moving lower. I know that Canadians in particular were very 
  upset with the liberalization of the U.S. voice frequencies some years 
  ago and declared that they would move down below the U.S. frequencies. 
  In fact, I remember someone commenting that if the U.S. ever increased 
  liberalization of the voice bands, they would just move down even 
  further. Since the more recent increase in voice bandwidths for U.S. 
  hams this may have caused at least some of this.

  Although on 40 meters you will often hear wide split operation because 
  those outside of Region 2 may not have as wide a band, I recently heard 
  a CU2 working narrow split down around the digital area. When the 10 
  meter band is open we can have many pirates operating in the text data 
  areas of the band since that likely seems like an unused part of the 
  spectrum to those stations.

  73,

  Rick, KV9U

  Brad wrote:
  > --- In digitalradio@yahoogroups.com, "Leigh L Klotz, Jr." <[EMAIL 
PROTECTED]>
  > wrote:
  > 
  >> I have ben hearing what sounds like Vietnamese on 14.070 LSB. I
  >> 
  > suspect 
  > 
  >> bootleg operation.
  >> 
  >
  > We hear a lot of that throughout 40, 30 and 20m and everywhere in
  > between. All Asian pirates, fishing vessels, phone patches, all sorts
  > of things. It can really ruin 10132 for a start.
  >
  > Brad VK2QQ
  >
  > 



   

[digitalradio] Fw: HAARP echo report

[Robert Chudek - K0RC]

- Original Message - 
From: Robert Chudek - K0RC 
To: [EMAIL PROTECTED] 
Sent: Friday, January 18, 2008 11:51 PM
Subject: HAARP echo report


Hello researchers,

I am located in East Central Minnesota (45.4123 N 92.8823 W) and am receiving 
the 6792.5 TX signal up to S-9 level. I have heard the moon echo several times 
for brief periods (10 ~ 15 seconds) with perfect Q5 copy. Many other times it 
is distinguishable but not very strong.

My receiver is a Kenwood TS-950SDX transceiver and I have a variety of 
antennas. The best antenna is the single element 40m Telrex dipole at 65 feet 
above ground. This is a full sized aluminum element approximately 76 feet long 
and is 2.5" diameter in the middle, tapering to 0.5" rods at the ends. It 
resonates at 7040 KHz.

I am recording this session using Audacity and can upload this file to my 
website for your download if desired. I'm not certain what size it will be, 
probably 50-Mb in MP3 format. I started recording at a wide bandwidth (5 KHz) 
but went down to 250 Hz for the best reception. I have a lot of local noise (S9 
+20 dB at wide bandwidth).

At 05:35 I also heard what sounded like Over The Horizon Radar scanning your TX 
frequency. This was 3 or 4 bursts of 20 seconds or so.

In Minnesota the conditions are clear, the moon is bright, it is high in the 
sky (overhead), and the temp is -12 F.

It is 05:44 now while I type this message and I am monitoring the experiment. 
For the past 30 seconds I could not tell the difference between the TX and the 
echo. Audio-wise, they are the same strength out of my speaker. I couldn't not 
see the signal meter from this side of the room.

73 de Bob - KØRC in MN

[digitalradio] Fw: [MWA] ARLX002 Lunar Echo Experiment looking for Amateur RadioParticipants

[Robert Chudek - K0RC]

- Original Message - 
From: "Robert Chudek - K0RC" <[EMAIL PROTECTED]>
To: "Minnesota Wireless Association" <[EMAIL PROTECTED]>; "TCDXA" 
<[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>
Sent: Friday, January 18, 2008 11:32 PM
Subject: Re: [MWA] ARLX002 Lunar Echo Experiment looking for Amateur 
RadioParticipants


>I am copying the TX signal (6792.5 KHz) about S-9 on peaks and at times 
>receiving the echo from the moon perfect Q5. The best antenna is my 40m 
>single element Telrex at 65 feet. It's a crisp, clear night (about -12 F 
>right now) and the moon is shining bright almost overhead. I'm recording 
>the audio using Audacity. Of course I also heard a couple of lids tuning up 
>on this frequency and covering up the signals at the beginning.
>
> 73 de Bob - KØRC in MN
>
>
>
> - Original Message - 
> From: "Robert Chudek - K0RC" <[EMAIL PROTECTED]>
> To: "TCDXA" <[EMAIL PROTECTED]>; "Minnesota Wireless Association" 
> <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>
> Sent: Friday, January 18, 2008 10:49 AM
> Subject: [MWA] ARLX002 Lunar Echo Experiment looking for Amateur 
> RadioParticipants
>
>
> Here's an opportunity for some unusual DXing on (near) the 40m band this
> weekend.
>
> 73 de Bob - KØRC in MN
>
> - - - - - - - - - - - - - - - - - - - - - - - - - -
>
>
>
> SB SPCL @ ARL $ARLX002
> ARLX002 Lunar Echo Experiment looking for Amateur Radio Participants
>
> ZCZC AX02
> QST de W1AW
> Special Bulletin 2 ARLX002
>>From ARRL Headquarters
> Newington CT January 17, 2008
> To all radio amateurs
>

[digitalradio] Primary communcation systems

[Robert Chudek - K0RC]

I am not a sailor nor do I have any experience "at sea". So as a layman, it is 
unfathomable to me that anyone would risk their life venturing out of port and 
rely on amateur radio for their communication needs.

Amateur radio for recreational use, certainly... a backup communication system, 
certainly... but IMO, it would be foolhardy to not have a primary safety system 
that reports location and status. The whole idea strikes me as penny wise, 
pound foolish.

The USCG requires safety equipment. Isn't a primary communication system on 
that list?

73 de Bob - KØRC in MN


  - Original Message - 
  From: Michael Hatzakis Jr MD 
  To: digitalradio@yahoogroups.com 
  Sent: Wednesday, December 26, 2007 1:02 PM
  Subject: RE: [Bulk] Re: [digitalradio] Questions on digital opposition



   This is meant as a couple of constructive, clarifying, questions for those
  > who express strong displeasure with Pactor.
  > 
  > Would you decrease your opposition if Pactor III did not expand its
  > bandwidth? 
  > 
  > Could you accept wide band digital modes if they all operated in a fixed
  > bandwidth, i.e. not expanding or contracting due to band conditions?
  > 
  > 
  > Rud Merriam K5RUD 
  > ARES AEC Montgomery County, TX
  > http://TheHamNetwork.net
  > 
  > 



   

[digitalradio] What's the roar?

[Robert Chudek - K0RC]

On 7147 KHz at about 14:00 UTC today there was a 10~12 KHz wide digital signal 
that was booming in. It's still there 2 hours later but only S-5 now. Can 
anyone tell me what this "noise" is about? It sounds almost at bad as the old 
Russian jamming signals from years gone by.

73 de Bob - KØRC in MN

Re: [digitalradio] FSK versus AFSK in BARTG ??????

[Robert Chudek - K0RC]

Andy,

There should be no detectable difference between an AFSK and FSK signal on the 
receiving end. Are you sure your tones were correct on FSK? The symptom you 
describe sounds like you may have been transmitting "reversed tones". There is 
a menu setting to flip the polarity of the FSK keying in the Kenwood. Give this 
a try. I have heard several stations that were "upside down" during this 
contest.

73 de Bob - KØRC in MN


  - Original Message - 
  From: Andrew O'Brien 
  To: digitalradio@yahoogroups.com 
  Cc: [EMAIL PROTECTED] 
  Sent: Saturday, March 17, 2007 10:25 PM
  Subject: [digitalradio] FSK versus AFSK in BARTG ??


  After several years of doing RTTY via AFSK, I thought I would use the
  BARTG RTTY contest this weekend to practice my FSK "skills" with the
  new radio.

  I was surprised that I was not being heard so well. I know the band
  is fairly poor but stations that I could hear fairly well would not
  respond to me, they often called CQ CQ after I called them. My
  antenna situation is not the best but I am used to being heard after a
  few tries. I did work some stations but much less than I am used to,
  I tried 40, 80 and 20M.

  Tonight, I tried again...just trying a few east coast stations, none
  were running pile-ups. Same result. many endlessly calling CQ and
  apparently not hearing my 100 watts of FSK.

  So, I switched to sound card AFSK and gave a call, first attempt the
  station came back to me. Another station then answered me on the
  second attempt. I switched back to FSK on the same band and antenna
  and very few responded.

  I'm new to FSK operations, is there something fundamental that I am
  missing? I am making sure I am transmitting on the same freq as I am
  receiving. I have made sure I have high tone selected properly. I
  set FSK for 100 watts with moderate amount of ALC showing. I set AFSK
  for 70 watts and NO ALC.

  It may still be just band conditions but I am wondering...

  -- 
  Andy K3UK
  Skype Me : callto://andyobrien73
  www.obriensweb.com


   

Re: [digitalradio] PSK and RTTY decode bult in to rigs

[Robert Chudek - K0RC]

Andy,

In my opinion, that feature is in a "gray area", between useful and practical.

I do believe this feature in the Icom has helped motivate many hams to give 
RTTY a try. Once they see the messages being exchanged, it becomes an incentive 
to investigate what is needed to participate. I suppose the same can be said 
about the standard soundcard feature found in new computers too.

In the practical sense though, the basic Icom feature is flawed for two-way 
communications. Yes, you can store TX messages and send them, but there is no 
practical way to send the other station callsign and engage in a regular QSO 
using the radio by itself. A keyboard interface for the radio could address 
this. Maybe a future "bell"???

BTW, the Icom decoder is top-notch for RTTY. I am not aware that it will decode 
PSK modes.

73 de Bob - KØRC in MN


  - Original Message - 
  From: Andrew O'Brien 
  To: digitalradio@yahoogroups.com 
  Sent: Saturday, January 27, 2007 8:57 AM
  Subject: [digitalradio] PSK and RTTY decode bult in to rigs


  I wonder about the performance of PSK31 and RTTY decoding that is
  built in to the firmware of rigs like the Icom 746 Pro. Does anyone
  use their rig in this way? How does the decoding perform, is it
  useful having in in a rig or is it just a bell and whistle that no-one
  really uses?

  -- 
  Andy K3UK
  Skype Me : callto://andyobrien73
  www.obriensweb.com


   

Re: [digitalradio] Interfacing a PK-232 to IC-746 (non-Pro)

[Robert Chudek - K0RC]

Dave,

Those connections are correct if your FSK signal transmits "right side up". If 
you discover it transmits "up side down", then use pin-4 on the PK-232 DIN plug 
instead of pin-1. I think the Icom radios work properly on pin-1 and the 
Kenwoods require pin-4.

73 de Bob - KØRC in MN


MN stations will be looking for your participation in the Minnesota QSO 
Party being sponsored by the Minnesota Wireless Association ( 
http://www.w0aa.org/mnqp.htm ) on Saturday Feb 3, 2007 beginning at 
1400 UTC. Join the fun!




  - Original Message - 
  From: Dave 
  To: digitalradio@yahoogroups.com 
  Sent: Friday, January 19, 2007 5:08 PM
  Subject: [digitalradio] Interfacing a PK-232 to IC-746 (non-Pro)


  Can anyone confirm my plan to run FSK RTTY with the PK-232 and the 746
  non-Pro using pin 1 from the 5-pin DIN plug on the back of the 232, to
  pin 1 of the ACC-1 jack on the back of the 746, and, of course, gnd to
  gnd? The 746 manual calls pin 1 of ACC 1 "RTTY" and states it
  "Controls RTTY Keying". Since there are no other obvious choices, this
  seems correct, but want to get some verification before I wire it up.

  Tnx es 73
  Dave
  KB3MOW