[FARC] PSK Questions

[M and J Gillespie]

Kirk,
I am unfamiliar with PSK operations but it is traditional to sign the very 
last words uttered on CW with "SK".  That means a final final on the QSO. 
On the other hand, "SK" may also be used in writing (as in QST articles) or 
on the air on CW and means "Silent Key"  (Someone has died in that case)

You probably already know that.  Oh, Well. Fodsr what it is worth.

73 de Jim, K3DQ

----- Original Message ----- 
From: "Kirk Talbott" <KirkTal7237 at msn.com>
To: "Frederick, Maryland ARC" <farc at mailman.qth.net>
Sent: Friday, July 06, 2007 11:05 AM
Subject: [FARC] PSK Questions


>I have some questions about PSK31 and Slow Scan TV for the group.
>
> One:  Hams on PSK31 use a Morse code shortcut language.  For example, a 
> typical CQ looks something like this. "CQ CQ CQ de W4XXX W4XXX PSE k."  I 
> know what the "de" and "k" stands for but what does "PSE" mean?  Another 
> example is the signoff.  "KB3ONM de W4XXX W4XXX 73 sk sk sk."  What does 
> the "SK" mean?
>
> Two:  On my software, WinPSK, there are some numbers displayed at the 
> bottom of the screen below the waterfall window.  One is IMD the other 
> PPM.  A read a little about IMD and found that it stands for 
> Inter-Modulation-Distortion. Ok, but what does that mean?  My 
> interpretation of the reading I've been doing, a high numbered IMD means 
> you're distorting and splattering all over the place and low a number 
> means you're getting close to a perfect signal. It's kind of like mic gain 
> in SSB phone. And like SSB phone, too low a mic gain means you're not 
> putting out enough "punch" in your signal. Does too low an IMD number in 
> PSK31 mean the same thing?  As for PPM, I have no idea on what this means 
> and can't find any info on it.
>
> Three:  I had one of my contacts give a signal report that went something 
> like this.  "Your RST is 599, and the waterfall display shows a near 
> perfect signal."  Ok, I understand what "599" is, but the reference to the 
> waterfall display and the near perfect signal has me baffled.  What are 
> they looking at in the waterfall that shows a near-perfect signal? My 
> software, WinPSK, is freeware and pretty limited.  So maybe it doesn't 
> show what other more sophisticated programs do.
>
> Four:  SSTV seems neat, but I can't seem to receive a signal strong enough 
> to get a decent picture.  The letters TV in SSTV seem a bit of a misnomer. 
> You can't really use video in slow scan TV....right?  What I see mostly on 
> SSTV are pictures that look like travel agency posters; beaches and palm 
> trees, mountains and lakes, etc. with call signs written on them. Is this 
> all there is to SSTV?
>
> Since June 26 I've had 38 PSK31 contacts.  I was going like gangbusters 
> there for a while.  July 4 and yesterday, I couldn't get one contact. On 
> SSB phone I didn't even hear one person on 20 or 10 meters, and I heard 
> only 2 people on 40 meters.  Sometimes on PSK31 I can contact Texas on 15 
> watts output, but then need 75 watts output to communicate with Florida. 
> HF is really "fickle" isn't it.  Analogous to fishing.  Throw your line in 
> the water and sometimes they're biting and sometimes they're not.  F. Gump 
> had it right about a box of chocolates and it applies to HF. "You never 
> know what you're going to get."
>
> 73
> KB3ONM
> Kirk
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