PSK31 question

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PSK31 question

Dan Barker
Question about transmitter drive setup.

I'm about to go on the air with the K2 Power knob full clockwise, and the
soundcard drive (Digipan) set for about 1A draw on key down. Is that right?

Dan / WG4S / K2 #2456 with KPSK2, er, ah KSB2

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Re: PSK31 question

zeke7237
I never ran across that method .. what I did (and seems to work OK and
sound reasonable) is to set power knob to desired power, then adjust
sound card level to just where agc blinks first LED ..

de John W1RT #3906


On Sat, 13 Nov 2004 15:52:33 -0500, Dan Barker <[hidden email]> wrote:

> Question about transmitter drive setup.
>
> I'm about to go on the air with the K2 Power knob full clockwise, and the
> soundcard drive (Digipan) set for about 1A draw on key down. Is that right?
>
> Dan / WG4S / K2 #2456 with KPSK2, er, ah KSB2
>
> _______________________________________________
> Elecraft mailing list
> Post to: [hidden email]
> You must be a subscriber to post to the list.
> Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/subscribers.htm
> Elecraft web page: http://www.elecraft.com
>
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RE: PSK31 question

Ron D'Eau Claire-2
In reply to this post by Dan Barker
Don't do that if you want to minimize distortion, Dan.

Elecraft warns against EVER running the K2 with the power control full "up"
in SSB modes, including PSK31. The IMD increases quickly when you exceed the
rated power level (10 watts or 100 watts PEP).  It's okay on CW, where the
finals don't have to be "linear" but they still recommend against turning
the POWER control to a setting above that which the K2 can actually deliver.

I set the soundcard drive to run BELOW the rated power so the ALC doesn't
kick in. If you've modified the ALC circuit to have a better delay
characteristic for PSK31 this isn't so critical, but I suspect it's a good
idea to avoid ALC action in any case. I switch the bargraph to ALC mode, set
my output power to 10 watts (or 100 watts if you're QRO) or less, then
adjust the signal in from the sound card to a point just BELOW that at which
the first ALC bar flickers. Actually I commonly set the POWER control for 10
watts, then adjust the soundcard drive for 5 watts output. That also ensures
the ALC is not being activated.

Also make sure your SSB Compression is OFF.

Ron AC7AC

-----Original Message-----
Question about transmitter drive setup.

I'm about to go on the air with the K2 Power knob full clockwise, and the
soundcard drive (Digipan) set for about 1A draw on key down. Is that right?

Dan / WG4S / K2 #2456 with KPSK2, er, ah KSB2


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Re: PSK31 question

Tom Arntzen
In reply to this post by Dan Barker
What I do is to set the power for 5watts in qrpmode and adjust PC to the
point where output just drop a little bit.
I think this will be almost the same as set power for 10 watts and adjust
pcoutput for 5watts.
Somehow I have never liked the second method because I like to limit my TX
the hard and secure way.
Some also advice to set tone for psk31 to a frequency so high that harmonics
is outside the passband the ksb2 is capable to send in.
If you have basic KSB2 you could set tone to 1200-1300hz.
Harmonics will then be attenuated.
But I have tried to send 1000hz tone with 5watt setting and pcoutput just at
droppoint.
Nothing sounds wrong on other rx in schack. No harmonics.

73 de Tom LA1PHA

----- Original Message -----
From: "Dan Barker" <[hidden email]>
To: "Elecraft" <[hidden email]>
Sent: Saturday, November 13, 2004 9:52 PM
Subject: [Elecraft] PSK31 question


> Question about transmitter drive setup.
>
> I'm about to go on the air with the K2 Power knob full clockwise, and the
> soundcard drive (Digipan) set for about 1A draw on key down. Is that
> right?
>
> Dan / WG4S / K2 #2456 with KPSK2, er, ah KSB2
>
> _______________________________________________
> Elecraft mailing list
> Post to: [hidden email]
> You must be a subscriber to post to the list.
> Subscriber Info (Addr. Change, sub, unsub etc.):
> http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/subscribers.htm
> Elecraft web page: http://www.elecraft.com
>
>


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Re: PSK31 question

Charles Greene
In reply to this post by Dan Barker
Dan,

Set the power at 6 watts, then adjust the audio drive so you get 5 watts
output.  You can also watch the ALC, with the ALC/RF on ALC.  It should
just begin to flicker on the far right hand side.  Press and hold ANT 1/2
and TUNE to read power forward power/reflected power.  The display should
read 6.0 F and 0.0r when your antenna it tuned up.  Note that when you
change audio frequency, you may have to readjust the audio drive because of
ripples in the OP1 filter bandpass.

73, Chas

At 03:52 PM 11/13/2004, Dan Barker wrote:
>Question about transmitter drive setup.
>
>I'm about to go on the air with the K2 Power knob full clockwise, and the
>soundcard drive (Digipan) set for about 1A draw on key down. Is that right?
>
>Dan / WG4S / K2 #2456 with KPSK2, er, ah KSB2


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