Message-ID: <009001c0b1a3$263c3740$687a37c0@w2ksn>
From: "Stewart Nelson" <sn@scgroup.com>
To: rsgb_lf_group@blacksheep.org
References: <3AB72FCB.11916.3A0834@localhost>
Subject: LF: Re: Success and failure
Date: Tue, 20 Mar 2001 17:06:23 -0800
Organization: SC Group
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Hi Mike,

If you're still having trouble with Jim's WOLF signal, please
email me a one minute .wav file, and I try to diagnose the
problem.  You can convert it to 8-bit samples to save some
space, if you like.  My mail server will accept attachments of
up to about 7 MB.

73,

Stewart KK7KA

----- Original Message -----
From: "Mike Dennison" <mike.dennison@rsgb.org.uk>
To: <rsgb_lf_group@blacksheep.org>
Sent: Tuesday, March 20, 2001 2:24 AM
Subject: WOLF: Success and failure


> I tried out WOLF for the first time last night with total success.
>
> Jim was sending GY(^%? JGGF, followed by H(*^RCKO KKl, followed by . . . .
>
> OK, so it wasn't quite as successful as I would have liked.
>
> My first problem was finding the Command Prompt (pseudo DOS) on
> Windows ME. After 20 minutes, I located it under Programs, Accessories!!
>
> I then successfully generated a test signal (WAV file) and 'received' it 100%
> as per the instructions. So WOLF is easy after all.
>
> Now for the big test - real RF. Jim came up with his test transmission and I
> recorded it using Spectrogram but this didn't work. The problem seems to be
> that WOLF needs a sample rate of 8kb, and Spectrogram doesn't do this rate.
> An hour later, I used Cool Edit (a nice program) to generate a usable WAV
> file of Jim's signal.
>
> Several hours later I gave up, having failed to read anything at all from Jim.
>
> Possible causes: Jim's signal is very strong so possible sound card level
> problem. Also I may have been a long way off frequency (see below). Will test
> further tonight.
>
> Getting the correct audio frequency proved difficult and I only fixed it this
> morning after breakfast. I can use BBC 198kHz to calibrate Argo to measure
> a 136kHz signal to much better than 1Hz, but could not find an easy way of
> measuring 800Hz!! First I believed the Argo readout at 800Hz, but later tests
> showed this to be a long way out (this is not a complaint against Argo). I
> finally listened to DBF38 on AM and beat my DDS against it, then used the
> resultant 800Hz beat note to calibrate Argo. Later I found the offset facility
on
> my IC-706. This sets the audio frequency for comfortable CW reception -
> normally about 400Hz. Setting this to 800Hz gave me 800Hz audio to within
> half a Hertz with the RF dial set to the correct frequency. Now why didn't I
> think of that in the first place?
>
> Some thoughts on WOLF:
>
> It looks very useful and I think it may well be the mode for the 2001/2002 DX
> season (though I will still run CW and QRSS).
>
> The command line is hard work and needs a lot of interpretation. I am sure
> there are programmers out there who could provide an easy display with
> 'switches' and 'dials', and some automation of the variables to optimise
> reception.
>
> Transmit is a bigger problem if you cannot generate high power SSB at
> 136kHz. Jim has cracked the problem with his Decca (Class D), and I look
> forward to him publishing his modulator circuit. His signal is VERY clean with
> me only a few km away.
>
> We will need to devise a protocol for QSOs.
>
> We will also need to find a way of having 'random' QSOs. At present the
> frequency must be known accurately in advance and monitored for a very
> long time. This is not viable if you don't know there is someone transmitting.
>
> I find WOLF fascinating and challenging, whilst - at least on receive - not
> needing huge amounts of work to get going.
>
> I hope Jim will continue his test transmissions to get more people set up.
>
>
>
> Mike, G3XDV (IO91VT)
> http://www.lf.thersgb.net
>
>