K3 & DM 780

[KD8NNU]

I want to use DM 780 with my K3 to work either CW or one of the data
modes.

I can get the DM 780 to decode signals, but if I try to TX, I am unable
to trigger the radio to do anything.

I have both a USB to serial connection, plus the sound card from the
laptop connected.  I have been reading the manual and a starter guide
someone sent me, but I am getting nowhere fast.  I did try different
settings for the PPT--KEY under the config menu, and I did get a solid
tone out of the monitor speakers but no TX.

If someone can point me to a resource on the intranet, I will glady do
some more reading.

Thx  Happy New Year
Don
KD8NNU

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

[Jim Brown-10]

On 12/31/2010 1:27 PM, [hidden email] wrote:
> I want to use DM 780 with my K3 to work either CW or one of the data
> modes.
>
> I can get the DM 780 to decode signals, but if I try to TX, I am unable
> to trigger the radio to do anything.

First, the K3 must be in the DATA A mode, and you need a cable from the
output of the sound card to the line input of the K3, and the playback
mixer in your computer must be set to send the .wav generated sound to
the computer output.  Second, you need to get the K3 to transmit. One
VERY easy way to do that is to use VOX.  That's what I do for both PSK
and RTTY. You can also do it by command from DM780. Don't ask me how --
it's been a couple of years since I've run PSK.  Third, you have to
place DM780 in transmit mode.  Study the doc for DM780 for answers to
both questions.  Next, you need a serial connection between the computer
and the radio. Use a real serial connection if your computer has one, or
a USB to serial if you don't.

There's a lot of detail about the various connections and how to set
levels in http://audiosystemsgroup.com/HamInterfacing.pdf   and in
http://audiosystemsgroup.com/RFI-Ham.pdf   Both are free downloads.  It
is VERY important to set levels correctly. If you don't, you can create
a lot of interference to other PSK users.  It's easy to get right if you
follow the instructions.

73, Jim Brown K9YC

73, Jim K9YC

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

[Don Wilhelm-4]

  Don,

Listen to the output of your soundcard with headphones (or your computer
speakers) while "sending" with PSK31 - if you hear the PSK31 "warble",
then your soundcard output is normal (you will likely only hear it in
the left ear).  Please verify this before anything else - if the
soundcard does not output the tones on the left channel, things will not
work.

Use VOX initially just to keep things simplfied - others have suggested
VOX settings.  For the time being, turn off PTT -- KEY in both the K3
and DM780.  Actually, using HRD/DM780, it is best to key the transmitter
through the RS-232 port than to use the DTR or RTS signaling (DM780
activates transmit through HRD - but HRD must be configured to activate
transmit too).  If you use DTR or RTS, those lines will become active
for a short period when you power the computer on, and will signal to K3
to go to transmit mode.

Put the K3 into TX Test and verify that the ALC meter goes up to 4 bars
with flickering of the 5th bar.  Adjust the Line-in level or the
soundcard output level to produce that amount on the ALC meter.  A word
about the K3 "ALC" meter - it does not indicate ALC until the 5th bar -
the lower levels are more like a VU meter to allow you to set the audio
level below that of the onset of ALC,

73,
Don W3FPR

On 12/31/2010 4:27 PM, [hidden email] wrote:

> I want to use DM 780 with my K3 to work either CW or one of the data
> modes.
>
> I can get the DM 780 to decode signals, but if I try to TX, I am unable
> to trigger the radio to do anything.
>
> I have both a USB to serial connection, plus the sound card from the
> laptop connected.  I have been reading the manual and a starter guide
> someone sent me, but I am getting nowhere fast.  I did try different
> settings for the PPT--KEY under the config menu, and I did get a solid
> tone out of the monitor speakers but no TX.
>
> If someone can point me to a resource on the intranet, I will glady do
> some more reading.
>
> Thx  Happy New Year
> Don
> KD8NNU
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html