QSK revisited

[Rajiv Dewan, N2RD]

After my last email on comparing QSK implementations in the K2 and  
the Yaesu FT-1000MP and the comments from knowledgeable people on  
this forum, I decided to measure carefully and to make more careful  
notes on what I heard.

I setup a K2 and an MP to transmit at the same frequency into dummy  
loads.  To test the K2, I transmitted continuously on the MP at a  
level where the K2 showed a steady S9 signal.  While this was being  
received by the K2, I set up my keyer to transmit the letter v at  
different speeds on the K2.  I listened to the K2 and analyzed the  
sound using Spectrogram.  I then did the whole thing with the MP as  
the device under test.

The details of the test, the results, and images of the Spectrogram  
screenshots can be found at http://rajiv.dewan.info/qsk/
My subjective opinion is that the K2 is great if all one is  
interested in is inter-character or inter-word reception. In fact,  
the hang time is so well calibrated that it is very silent and easy  
on the ears. This is especially important for long contests.

Inter-element reception is very demanding. For this purpose, I prefer  
the Elecraft K2 while transmitting up to 20wpm. At 25wpm or greater,  
the K2 essentially does not receive between elements.  At 30 wpm  
Yaesu still has a usable QSK implementation but the extra noise is  
tiring. I do not think I could stand the noise from 30wpm or faster  
for long during a long contest.  Hang time can be increased (Menu  
item 7-4 increased from 5 to 7 or 10ms) to where the QSK would be  
essentially be useless between elements but would serve some purpose  
to detect signals between words.  With the increased hang time, where  
inter-element QSK is essentially disabled, I prefer the K2 as the  
Yaesu remains noisier.  I will have to try even larger hang times and  
compare the sound.

Hope you find this interesting,

Raj, N2RD

K2#5613



--
Rajiv Dewan, N2RD
[hidden email]
FN13fc

--

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[N2TK]

Hi Raj,

Tnx for the info from your tests.

I find I really like QSK when I'm trying to work DX, like with the current
4O3T operation. But when I am running stations in a contest I do not use
QSK. Too rough on the ears using QSK all the time. But with good QSK you can
pick out your call right away when 4O3T came back without guessing or asking
for repeats. Even at the speeds 4O3T was using on the high bands it sounded
good and you can hear between the elements without pops with the TS950SDX
and Acom 2000A.

I made the R17 mod plus I set T-R to I believe .01 or .02 which got rid of
the pops. It sounds quiet. Just can't hear between the elements. But that is
okay since I use the K2 for Dxpeditions.

N2TK, Tony


-----Original Message-----
From: [hidden email]
[mailto:[hidden email]]On Behalf Of Rajiv Dewan, N2RD
Sent: Monday, July 24, 2006 2:00 PM
To: elecraft
Subject: [Elecraft] QSK revisited

After my last email on comparing QSK implementations in the K2 and
the Yaesu FT-1000MP and the comments from knowledgeable people on
this forum, I decided to measure carefully and to make more careful
notes on what I heard.

I setup a K2 and an MP to transmit at the same frequency into dummy
loads.  To test the K2, I transmitted continuously on the MP at a
level where the K2 showed a steady S9 signal.  While this was being
received by the K2, I set up my keyer to transmit the letter v at
different speeds on the K2.  I listened to the K2 and analyzed the
sound using Spectrogram.  I then did the whole thing with the MP as
the device under test.

The details of the test, the results, and images of the Spectrogram
screenshots can be found at http://rajiv.dewan.info/qsk/
My subjective opinion is that the K2 is great if all one is
interested in is inter-character or inter-word reception. In fact,
the hang time is so well calibrated that it is very silent and easy
on the ears. This is especially important for long contests.

Inter-element reception is very demanding. For this purpose, I prefer
the Elecraft K2 while transmitting up to 20wpm. At 25wpm or greater,
the K2 essentially does not receive between elements.  At 30 wpm
Yaesu still has a usable QSK implementation but the extra noise is
tiring. I do not think I could stand the noise from 30wpm or faster
for long during a long contest.  Hang time can be increased (Menu
item 7-4 increased from 5 to 7 or 10ms) to where the QSK would be
essentially be useless between elements but would serve some purpose
to detect signals between words.  With the increased hang time, where
inter-element QSK is essentially disabled, I prefer the K2 as the
Yaesu remains noisier.  I will have to try even larger hang times and
compare the sound.

Hope you find this interesting,

Raj, N2RD

K2#5613



--
Rajiv Dewan, N2RD
[hidden email]
FN13fc

--

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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

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Elecraft web page: http://www.elecraft.com

_______________________________________________
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