The ins and outs of PSK on the K3?

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The ins and outs of PSK on the K3?

tomb18
I have been running PSK for a couple of months now on the K3 and am wondering if I am using it in the best way.
I am using DM780 that comes with Ham Radio Deluxe and I usually set the K3 in USB and pick the stations from the waterfall. I also have a P3. Up until now, I have been using the 2.8 KHz filter setting and have had AGC on.  It always seemed that there were two flaws in this:  One was that it was not easy to pick the actual signal using the P3 markers, you always were using the USB lower frequency point that was some number of hz away from the signal.  The second was how do you get an actual frequency for the signal instead of just 14.070 (20M)?  Sometimes you can see stations spotted at 14.072 but finding it was always a search of spots one by one.


Today I played around a bit.  For one, I used the manual notch filter to remove a really strong signal.  I turned of AGC. This works well.  I also set the radio in DATA mode instead of USB.  The nice thing about this, is that I can use the P3 with a +/- 2 KHz span, and see all of the signals in the usual PSK range, but now I can click on one I see, and it will actually center it in the passband and give me a frequency readout that seems better than the standard 14.070 for 20m.  Furthermore, I can use a narrower filter and the reception seems much better and the decoding more accurate.

So my question is, is my new found way of using the K3 a better way and possibly the best?
Thanks for any insight.
Tom VA2FSQ

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Re: The ins and outs of PSK on the K3?

Don Wilhelm-4
Tom,

There is nothing wrong with the way you are doing it - and works well
for anyone having a panadapter display to work with (P3 or LP-Pan)  With
that you can narrow up the filters and eliminate interference.
If you do it that way (tune the K3 to the signal desired rather than
clicking on a waterfall), then you may want to investigate using the K3
Utility terminal rather than DM780 if all you want to decode is PSK31 or
RTTY, or you might want to investigate Fldigi and give the K3 polling
(and your computer reaources) a rest.

OTOH, there is a convience to using that full SSB bandwidth (but in DATA
A submode) along with a waterfall display.  Click on a signal on the
waterfall, the K3 frequency does not change, but the PSK31 application
shows you the frequency of the signal.  Yes, using that wide bandwidth,
you would want to turn AGC off, or if that is not desirable, turn the RF
gain down as required - the soundcard application filters are plenty
good, but strong signals within the bandpass will pump the AGC and
change the gain of the receiver.  One problem with HRD/DM780 is that it
does not properly recognize the K3 data submodes and will force your K3
to USB if you allow it to do whatever it wants - you can change the mode
manually to DATA A, but that is a pain.  I gave up on HRD for exactly
that reason.  I use Fldigi with RigCAT selected.

73,
Don W3FPR.

On 6/26/2012 8:36 PM, tomb18 wrote:

> I have been running PSK for a couple of months now on the K3 and am wondering
> if I am using it in the best way.
> I am using DM780 that comes with Ham Radio Deluxe and I usually set the K3
> in USB and pick the stations from the waterfall. I also have a P3. Up until
> now, I have been using the 2.8 KHz filter setting and have had AGC on.  It
> always seemed that there were two flaws in this:  One was that it was not
> easy to pick the actual signal using the P3 markers, you always were using
> the USB lower frequency point that was some number of hz away from the
> signal.  The second was how do you get an actual frequency for the signal
> instead of just 14.070 (20M)?  Sometimes you can see stations spotted at
> 14.072 but finding it was always a search of spots one by one.
>
>
> Today I played around a bit.  For one, I used the manual notch filter to
> remove a really strong signal.  I turned of AGC. This works well.  I also
> set the radio in DATA mode instead of USB.  The nice thing about this, is
> that I can use the P3 with a +/- 2 KHz span, and see all of the signals in
> the usual PSK range, but now I can click on one I see, and it will actually
> center it in the passband and give me a frequency readout that seems better
> than the standard 14.070 for 20m.  Furthermore, I can use a narrower filter
> and the reception seems much better and the decoding more accurate.
>
> So my question is, is my new found way of using the K3 a better way and
> possibly the best?
> Thanks for any insight.
> Tom VA2FSQ
>
>
>
> --
> View this message in context: http://elecraft.365791.n2.nabble.com/The-ins-and-outs-of-PSK-on-the-K3-tp7558230.html
> Sent from the Elecraft mailing list archive at Nabble.com.
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Re: The ins and outs of PSK on the K3?

vk4tux
In reply to this post by tomb18


On 27/06/2012 0:36, tomb18 wrote:
> I have been running PSK for a couple of months now on the K3 and am wondering
> if I am using it in the best way.
> I am using DM780 that comes with Ham Radio Deluxe and I usually set the K3
> in USB and pick the stations from the waterfall. I also have a P3. Up until
> now, I have been using the 2.8 KHz filter setting and have had AGC on.
I have used like this, but with agc always off and filter from wide to
narrow settings depending on usage, i.e. dxpedition narrow on qrg etc.#
Indicated waterfall audio freq is added to vfo freq to spot, i.e.14070 &
1500hz for 14071.5 etc.
>   It
> always seemed that there were two flaws in this:  One was that it was not
> easy to pick the actual signal using the P3 markers, you always were using
> the USB lower frequency point that was some number of hz away from the
> signal.

> The second was how do you get an actual frequency for the signal
> instead of just 14.070 (20M)? see # above
Sometimes you can see stations spotted at 14.072 but finding it was
always a search of spots one by one. Today I played around a bit. For
one, I used the manual notch filter to remove a really strong signal. I
turned of AGC. This works well. I also set the radio in DATA mode
instead of USB. The nice thing about this, is that I can use the P3 with
a +/- 2 KHz span, and see all of the signals in the usual PSK range, but
now I can click on one I see, and it will actually center it in the
passband and give me a frequency readout that seems better than the
standard 14.070 for 20m. Furthermore, I can use a narrower filter and
the reception seems much better and the decoding more accurate. So my
question is, is my new found way of using the K3 a better way and
possibly the best? Thanks for any insight. Tom VA2FSQ -- View this
message in context:
http://elecraft.365791.n2.nabble.com/The-ins-and-outs-of-PSK-on-the-K3-tp7558230.html 
Sent from the Elecraft mailing list archive at Nabble.com.
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Re: The ins and outs of PSK on the K3?

tomb18
In reply to this post by Don Wilhelm-4
Hi,

I did try what you suggested, but on the P3 when you use data a mode, if you click on a signal on the P3, the marker is way outside the filter region.  It seems if you put the K3 in PSK-D mode and use the P3 (and soundcard) then what you click on is pretty well in the middle of the waterfall and you can zero in on it quite well.  Things sound a little funny though, compared to USB or data A.  Is this a normal situation?
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Re: The ins and outs of PSK on the K3?

Bill Frantz
[Just catching up with the list]

My latest PSK method in my continuously evolving technique using
the K3 is:

     Lock the K3 on the base frequency in DATA-A mode. (When I
     adjust the hi and low cut knobs I frequently bump the big
     tuning knob.)

     Set the low cut to 300 and high cut to 2400 so there won't be
     any falloff of signals at the ends of my 2KHz waterfall.

     Poke at signals on the waterfall for contacts. Use the manual
     notch filter to remove any single very strong signal if
     necessary.

     When I start a QSO, narrow the hi and low cut to about 150 Hz
     around the signal. Adjust the RF gain until the band noise is
     barely visible on the waterfall. Tune the signal with both
     "receivers" in my computer software (cocoaModem on a MacBook
     Pro), which will generally give a 1 Hz or so difference and
     improve decoding.

     When the QSO is over, open the bandwidth back up and continue
     searching.

When I'm calling CQ, I narrow the bandwidth as above so I can
detect weak responses.

I have a macro to open the bandwidth, but because the audio
frequency of the QSO is variable I haven't automated the
narrowing of the bandwidth. I am thinking of making a mod to
cocoaModem to send a command to the K3, but this project will
have to wait until at least September.

One other issue is that the noise reduction in cocoaModem is
quite effective when the bandwidth is open, but it becomes much
worse when the bandwidth is narrowed. The K3 does not provide
noise reduction in Data-A mode.

Cheers - Bill, AD6JV

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