Elecraft › [K2]

K2 and data modes

Classic

List

Threaded

2 messages Options

n0jrn

K2 and data modes

OK, I've been digging around in the archives trying to answer this question
and really haven't found the answer.

SO, what is the best set-up for running digital with the K2.

I'm running Windows 7 64 bit on a new HP desktop with integrated RealTec
soundcard. Using HRD and DM780.........

I have not set-up an interface between the PC and the K2 just yet.

Just wondering what others are using and how you hooked that to the K2.

HRD handles rig control and PTT just fine but I have no output for Digital
modes. When sending PSK, the rig will go into TX but no output power and
no ALC defection.

No surprise there since I'm not putting any audio back into the K2.

Anyway, I assume the only way to feed audio into the K2 is via the mic jack???

OR it there a mod I haven't heard about ??

thanks in advance for any info:

73 Jerry N0JRN
______________________________________________________________
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

Re: K2 and data modes

Jerry,

The K2 does quite well for digital modes, but yes, an audio interface
needs to be added.
Actually, that interface does not have to be complex - a couple
transformers and resistor dividers to handle the level change. If you
are using HRD, it can initiate transmit through commands to the K2, but
not all data applications have that capability, so I suggest you add the
simple PTT keying circuit too.

For one example, I refer you to my website www.w3fpr.com. There is an
Interface box for digital modes there that may give you some ideas (the
information is outdated, but you can still get some ideas from it).
Also take a look at the Fixed Audio Output for the K2 both on my website
and on Tom Hammond's site www.n0ss.net. That allows you to add an audio
output that is independent of the AF gain control. Unfortunately,
boards are no longer available, but the circuit is easy enough to wire
on perfboard. If you choose to do that, I suggest you follow the layout
on Tom's webiste so all the components lay down on the board and the
board can easily be mounted between the Control Board and the Front
Panel. I use microphone pin 5 for the fixed audio output (My mic jack
is wired for the Elecraft configuration and pin 5 is unused)

For an easily constructed interface in kit form, take a look at Skip
Teller's interface featured in July 2010 QST (page 37ff). This
interface is simplicity itself. Skip did offer a kit, but the listed
website is "temporarily unavailable", so I suggest an email to him
inquiring about kit availability - [hidden email]. As of July
2010, boards only were $7.95 (shipping included), and kit without cables
was $19.95 plus $4.50 shipping, and $29.95 plus $4.95 shipping for the
kit with cables.

OK, that will take care of the hardware.

The K2 can enable the RTTY filter set (using the secondary menu), which
is handy for data mode use because the compression setting is
independent of the SSB setting (data modes should use a compression of 1-1).
I suggest setting the RTTY FL1 to OP1 with the BFOs set exactly like the
SSB FL1 BFOs. That will give you a full waterfall spectrum that is most
commonly used for data modes like PSK31. The other filters, I usually
set to FL2=1.00, FL3=0.70, and FL4=0.40 centered on 1000 Hz. The choice
of 1000 Hz rather than any other (like the traditional RTTY mark
frequency of 2125 kHz is due to the limited range of the K2 BFO which
will not allow a narrow filter to be used at that mark frequency in LSB
mode (hint - use 915 Hz for the mark frequency in MMTTY or other).
These filters will allow you to tune (with the VFO) the desired signal
to near 1000 Hz on the waterfall and if QRM is present, you can narrow
the filters and still maintain contact.

I hope that helps with your choice of soundcard interfaces. There are
several available commercially that have a lot of "bells and whistles",
and that may be your choice if you do not want to build anything - but
the basic audio interface is not complex at all, you can build your own
if you desire, and it is a whole lot less expensive than the commercial
versions. Of course, if you need an additional soundcard for that
computer, then those interfaces with an integrated soundcard will serve
you well.

One additional point - regarding USB to serial adapters. Choose one
with an FTDI chipset for best results. I have tried a couple of the
Prolific adapters, and they do not provide good connections at the K2's
"slow rate" of 4800 bps - the FTDI adapter does better.

73,
Don W3FPR

On 4/3/2011 7:05 PM, Jerry wrote:

> OK, I've been digging around in the archives trying to answer this question
> and really haven't found the answer.
>
> SO, what is the best set-up for running digital with the K2.
>
> I'm running Windows 7 64 bit on a new HP desktop with integrated RealTec
> soundcard. Using HRD and DM780.........
>
> I have not set-up an interface between the PC and the K2 just yet.
>
> Just wondering what others are using and how you hooked that to the K2.
>
> HRD handles rig control and PTT just fine but I have no output for Digital
> modes. When sending PSK, the rig will go into TX but no output power and
> no ALC defection.
>
> No surprise there since I'm not putting any audio back into the K2.
>
> Anyway, I assume the only way to feed audio into the K2 is via the mic jack???
>
> OR it there a mod I haven't heard about ??
>
> thanks in advance for any info:
>
> 73 Jerry N0JRN
> ______________________________________________________________
> 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