[RTTY] FT2000 & AFSK

[Anthony J. Cioffi (N2KI)]

Chen, et al

Well we finally got things working properly.  It ended up being some
incompatibility with running MMTTY (stand alone) with Vista.

After we made all the suggested changes, adjustments and continuity checks,
we still had no inbound audio to MMTTY and the CAT was still not
functioning. At that point the last hair fell out.

We then tried DXLab Suite (which is what Mike uses as a logging program).
The Commander module picked up the CAT frequency immediately, and Win
Warbler (with MMTTY decoder enabled) worked perfectly.  All that was left
was to adjust the display frequency to read the mark tone.   The 1000MP has
a menu setting to adjust the frequency downward 2.125 kHz to reflect the
mark tone frequency when using AFSK.  Interestingly enough, the FT2K seems
to already do that.  My MP is adjusted down 2.125khz and all the time we are
trying to adjust the FT2K we were always off by 2.125 on the FT2K readout.
Adjusting the menu 72(?) back to zero put both the FT2K in sync with the
1KMP readout.

So there you have it.  Vista strikes again! Oye! 

Listen for a new RTTY contester (Mike - K2CYE) this weekend in the RU.

Thanks to all who chimed in to help.  Print you in the Round Up!


Anthony - N2KI
 www.n2ki.com


-----Original Message-----
From: Kok Chen [mailto:chen at mac.com] 
Sent: Thursday, January 06, 2011 3:32 PM
To: mmoran1027 at gmail.com
Cc: Anthony J. Cioffi
Subject: Re: [RTTY] FT2000 & AFSK

Hi Mike and Anthony,

I found a "Miscellanous AFSK-based Data Modes" section in the FT-1000
manual.

Turns out that unlike the FT-1000MP, VOX will work for "Packet" mode on the
FT-2000.  So you won;t even need a SignaLink to key the PTT.

The manual says:

> When you have configured Menu item "137 tGEn VOX SEL" to "dAtA," the
transceiver will operate in a "VOX" mode, and it is not necessary to connect
a PTT line.

But thats besides the point since you have the transmit direction working
already.  But good reference point for the future.

OK, on to Packet mode...

Take a look at he section called "Menu Mode."  In the Mode-DAT group, you
will see

> 064 dAtA DATA IN  


(this should not be a problem, since your transmit is working, but it should
say "dAtA")

> 065 dAtA DT GAIN  


(transmit gain -- adjust if you are over modulating or undermodulating, and
the SignaLink does not provide suffition Tx control range -- there should be
no ALC when you transmit with AFSK).

> 066 dAtA DT OUT  


be sure to select "nAin" in menu 066

> 067 dAtA OUT LVL 


this could potentially be your problem -- it may be set too low (the manual
says it defaults to 50, though).

> 070 dAtA PKTDISP  


this is the VFO dial offset that I mentioned in my original email.  If you
use LSB and a 2125 Hz Mark tone, set this to -2125 (minus!), and your VFO
dial will show the Mrk frequency of the received signal.  

It should not cause you not to see any signal.  It only affects the VFO dial
setting.

> 071 dAtA PKT SFT 


I think this may be the magical setting since it mentions the center
frequency, blah blah.  If you are using the 2125/2295 tone pair in your
software, try a value of 2210 Hz.  The manual mentions plus and minus signs,
but that may be a misprint.  If it really has plus and minus signs, try
both.

If I were you, I would play around with Menus 066, 067 and 071, while
monitoring the output on a program that supports waterfall displays.
cocoaModem has a spectrum display just for doing experiments like this, but
the program you use might not.  If not, find a program (even a general audio
recorder) that does.

Again, if you see nothing in a wideband display (not even a Mesa looking
bandpass hump in a spectrum display), I would check the wiring between the
SignaLink and the rig's Packert DIN connector.  For example, this is what I
see (just band noise, no signal) on a K3 with its filter set to 500 Hz
bandwidth and centered at about 2100 Hz: