[NLRS] PSK31 *in general*

[John (JK) Kalenowsky, K9JK]

Dan (mostly, but hopefully of interest to "All"),

I've never actually tried transmitting PSK31 on any band but have been 
amazed by 'experimentation' on 20 meters, just listening.

The best example I can site is one of my first tries...I had just downloaded 
one of the sound card based PSK31 programs and all I had was a headset with 
a mic input so I layed it over the speaker of my transceiver...ACOUSTICALLY 
coupled...tuned in a station that was transmitting PSK 31 and there it was, 
the letters of the text appearing on the laptop screen...I was pretty 
amazed. Turns out the station I had tuned in was in Jacksonville, Florida 
and was in QSO with a station somewhere in Michigan. As he turned it back to 
the station in Michgan, I figured that was it...fun was over BUT...what was 
this...after a short pause, more TEXT appearing on the screen and I could 
see the signal in the waterfall display...the program was decoding the text 
from the station in Michigan yet I COULD NOT tell that a signal was there in 
the speaker audio...sounded just like the noise from an 'open' receiver on a 
non-busy frequency. With THAT I was *truly* amazed.

I'd imagine that PSK31 should certainly work when you 'can "hear" each other 
down in the static but can't copy' and might even work at signal levels 
below that. Andy's post about frequency stability is certainly something to 
consider though I believe that many (most? all?)of the programs have 
automatic frequency correction (AFC) but they ARE focused towards HF so they 
might not have the range for VHF.

I also second Jerry's comments and sounds like you have done what you can at 
the Brainerd end but maybe the folks in the twin cities can put up a longer 
antenna on their end (that helps in both directions).

If nothing else...give it a try...let us know your results. Maybe your 
experiences could result in a paper you could present at the CSVHFS 
Conference next year!

73, JK

----- Original Message ----- 
From: "Dan Larson" <kc0luy at arrl.net>
To: "Gerald" <geraldj at ispwest.com>; <nlrs at mailman.qth.net>; "Chris Cox, 
N0UK" <chrisc at BritishCarAndDriver.Com>
Sent: Monday, August 29, 2005 11:34
Subject: Re: [NLRS] PSK31 on 2m SSB




Well, there *are* limitations to what I an attach to my camper!

First of all, I don't have a clear shot at the sky unless my mast was
40ft high to get *over* the tops of the oak trees, the branches of which
spread above my camper. Not to mention, that there is not enough room
in my "lot" to bring down guys to stabilize a mast that high. 25Ft is
the best I can really do without the objections of my "neighbors", the
campground owner, and my XYL ;-) A 15 element beam would hit the trees
as it spun around. Terrain-wise, its flat.

I get lots of questions already about my "TV antenna". At least they don't
see the HF wire strung through the trees unless they stand right under it!

I am feeding the 6-element homebrew yagi with RG-8X from the "candy store"
in Moundsview. Not the greatest stuff, but there's only 30 ft of it to
my radio. Yeah, sure I can run some LMR400 up there instead, but the XYL
won't be happy with the insect life forms exploiting the 1/2 gap in the
window, nor the 1/2 inch hole in the side of the camper either ;-)

I am using those "Made in U.S.A" silver plated teflon PL259's, and I did
fine job soldering. I checked the feedline with my MFJ-269 for shorts or
any other problems. I'm pretty picky about that part. I agonized and fretted
over my own design using simulation software until I could not stand it any
more. I built the darned thing out of 3/8 Al tube from McMaster-Carr. Its a
short boom design optimized for FB ratio and fed with a gamma tube. The
software predicts a 60 degree "view" angle of -3dB from peak gain. Its about
the best I could get on a 6' boom. ( < 1WL) According the the software, it
ought to be about 11dB of forward gain, ground and such taken into account.

The only real obstructions to the signal path are the oak trees & their
leaves. The elevation at my "weekend QTH" is about 300ft higher than
the other station I am trying to reach in Hastings. (The south part of town
with a great view of the horizon, not the lower part of town with
"Holywood Hill" in the way...)

What I am *really* want to know is how much PSK31 can help in my less than
ideal situation.

Dan
KC0LUY

On Mon, 29 Aug 2005 09:23:50 -0500, Gerald wrote:

>Antenna? feedline? You loose a lot in RG-58. 6 elements is a start. 15
>from a reputable maker can make a huge difference in performance.
>Antennas and fat feed lines help both ends. Hygain and crumcraft are not
>reputable vhf beam makers. Well, they have a reputation, all bad. M2,
>K1FO designs, and DL6WU designs (when made in aluminum, not steel) are
>good designs.
>
>I've worked mobiles out to 200 miles without enhancements, beam to beam
>should do better.
>

On Mon, 29 Aug 2005 10:33:07 -0500 (CDT), Chris Cox, N0UK wrote:

>Dan,
>
>with the amount of power that you're using, 125 miles should be a piece of
>cake under normal conditions on two.  Are you using decent quality cable
>and connectors and how obstructed is the path?
>
>Chris



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