[TenTec] Digipan/Winpskse on Pegasus

Mark Erbaugh mark@microenh.com
Mon, 9 Sep 2002 11:29:33 -0400


I run Digipan all the time on my Pegasus.  For just receiving data, all you
need to do is connect the supplied cable (1/8" stereo plugs on both end)
between the line out on the Pegasus and the line in on the computer
soundcard. No additional interface is needed, the level of the line out jack
on the Pegasus is designed to work with coumputer soundcards. It works for
me even without an isolation transformer.

If you want to transmit (and why wouldn't you), a simple interface is all
you need. One that I like is the "Rascal" from K4ABT. Check out
http://www.packetradio.com/psk31.html . If you don't want to buy his kit,
you can download the schematic and build your own, although if you have to
buy the parts new, you're probably better off buying the kit. I modified the
kit in two ways:

The obvious connection for such an interface is to the the accy jack on the
Pegasus. For some reason, the audio out level on that jack is considerably
higher than on the line out. It appears to be by design, but that means that
you really need to attunate that signal. I was overdriving the soundcard
with the audio input volume near minimum. With the Pegasus control software
(both TT and N4PY), you can reduce the line level output, but unfortunately,
that also reduces the audio output level. At K4ABT's suggestion, I put a 600
(approx - use any close value, or even a small trim pot ) ohm resistor
across the input to drop the level.

The second mod concerned the signal line that keys the PTT. When building
the kit it tells you which signal line to use in the supplied DB9 cable if
you want to use DTR or RTS. Most software allows you to choose which signal
you want to use. However, I have run across one package (WriteLog) that
didn't. It only used RTS and I had wired my interface for DTR. The mod I
made was to add a SPDT center off toggle switch to select which line is
used. The center off position is useful as an emergency PTT stop if
something on the computer keys the port at the wrong time.

As an alternative to the Rascal, the RigBlasters will work well. The
RigBlasters don't interface the audio out of the radio, but since the
Pegasus has the line out jack that works perfectly, that's not an issue.
The audio input on the Pegasus Accy jack is actually still at microphone
level ( not line level ), so the microphone output of the RigBlaster should
work fine. I've have the RigBlaster plus, but I suspect that the NoMic
(least expensive) should work fine hooked up to the Accy input. You don't
need a mic input on the interface as you can leave your mic connected to the
Pegasus mic jack. Only one input (mic or accy) is active at a time, so you
don't have to worry about transmitting shack audio when using the accy

One interface that I have been unable to get working is the SignaLink from
TigerTronics.  This interface doesn't have a serial port input for PTT
control, instead it detects the audio level from the sound card and triggers
PTT on that (SOX - sound operated transmit). It's supposedly more reliable
than transceiver VOX. The problem that I had with it is that the mic input
level on the Pegasus seems much lower than they are expecting. When I adjust
the soundcard level to where it triggers the SOX, it is overdriving the
Pegasus.  I've contacted TigerTronics. They said their unit is designed for
mic output levels of 50mV, while the Pegasus is looking for about 5mV. They
gave me some suggestions for dropping the output level, but the first one
that I tried wasn't enough attenuation. I need to work on it some more. They
also told me that the would custom modify a unit for me if needed (I think
for around $10). The unit is constructed with SMT, so that may not be a bad

----- Original Message -----
From: "Bill Fulling" <w4njf@midflorida.com>
To: <tentec@contesting.com>
Sent: Wednesday, September 04, 2002 7:15 AM
Subject: [TenTec] Digipan/Winpskse on Pegasus

> Has anyone tried running Digipan or WinPSKse on the Pegasus(or the Jupe
running in Peg emulation mode)?Would be interested in hearing from you.
> PS On this PTO grease,when I was an actual Maytag repairman we rebuilt the
timers in washers and dryers.The lubricant we used is called "Sylglide" and
worked great.It comes in a tube and can be found at any appliance parts
> 73 de W4NJF
> Bill Fulling
> w4njf@email.midflorida.com
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