Re: [IRCA] QRRe: A idea for future DX Tests.....

["Les Rayburn" <les@xxxxxxxxxxxxxxxx>]

Brandon's points are well taken, as are Russ's. For those who
are new to this technique, the performance of the mode works
out pretty closely to a simple logarithmic formula.

If dot length is 1 second, then the same signal with a 2 second dot
length works twice as well. Not quite, but close enough for this
discussion.

The limiting factor on LF has always been stability of the receiver and
transmitter (which is why TXCO's are often used) and the time of the
propagation window. Commercial transmitters are usually pretty stable,
so dot lengths at 1 second or even longer shouldn't be a problem.

Using this technique it's quite common to detect and identify signals
visually that are a good 10db or more under the "noise floor". That would
make coast to coast receptions of even graveyard tests possible----
and spectacular receptions from places like New England, Alaska, or
Hawaii achieve.

I'd love to test the theory with a willing station soon. If we continue to 
include
sweep tones, Morse Code at normal speeds, etc. then I don't see why
anyone would object.

73,

Les Rayburn, N1LF
NRC/IRCA Broadcast Test Coordinator
Please call anytime 24/7 if your transmitter
will be off the air for maintenance.
(205) 253-4867



----- Original Message ----- 
From: "Brandon Jordan" <brandon@xxxxxxxx>
To: "Les Rayburn" <les@xxxxxxxxxxxxxxxx>
Cc: "Mailing list for the International Radio Club of America" 
<irca@xxxxxxxxxxxxxxxx>; "NRC AM List" <am@xxxxxxxxxxx>
Sent: Monday, March 19, 2007 2:50 PM
Subject: Re: QRRe: [IRCA] A idea for future DX Tests.....


> Les Rayburn wrote:
>
>> I'm all for Brandon's suggestion. This technique is called QRSS (Slow 
>> Speed CW..."
>
> Hi Les, thanks for copying this message to me directly, as I have yet to 
> see it via the IRCA list.
>
> I am familiar with LF QRSS experiments with *extremely* slow morse, to 
> where a single dot is a minute or more. This isn't where I am going 
> really. I'm pushing towards a happy medium to where the CW characters are 
> simply long enough for Spectrum Lab, running at a normal waterfall speed, 
> can easily display the morse characters.
>
> If you take a look at the Spectrum Lab dump I posted in a previous 
> message, you can see that Spectrum Lab is already displaying the breaks 
> between the CW words, i.e. DE and KTMI etc, at the normal slow speed CW 
> the stations normally use. Lets take it down a few notches, if the morse 
> was running at a speed of where the dots were 1 second, the dashes 4 
> seconds, spaces between letters 2 seconds and spaces between "words" 3 
> seconds, then Spectrum Lab could easily display the morse characters right 
> there on the waterfall.
>
> I'm thinking easy mode and not hard core QRSS which is pretty specialized 
> and does take TXCO's, etc. I'm looking to where a DXer with just an 
> average receiver that has SSB capabilities, a PC with a sound card and 
> running the freeware Spectrum Lab can easily monitor a test and "see" the 
> CW ID's, even so weak the ear can't detect them, right there in Spectrum 
> Lab. That's why in the Spectrum Lab dump I posted, I used USB with a 3 kHz 
> bandwidth filter. Now that I think about it, I bet it is possible for a AM 
> only receiver to display the 1 kHz CW tones in Spectrum Lab.
>
> This sounds so do-able, and able to take these DX Tests to a whole new 
> level. Coast to coast loggings, and giving foreign DXers a real shot at 
> conclusively IDing these tests. All without fancy equipment. :)
>
> 73,
> Brandon Jordan
> Memphis, TN
> www.bcdx.org 

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