[Lowfer] QRSS Alternative

[lowfer@mailman.qth.net]

Hello Gary,

Thanks for the reply and a chance to explain some of the things that I
surely have left out.
----- Original Message -----



> Have you done a Google search on DFCW AMATEUR RADIO ?  You will find =
lots
of
> comments about using it, but in amongst the hundred or so hits will be =
a
few
> discussions on the hows and whys and pitfalls.  The DF is dual =
frequency
and
> easier to generate and would use less bandwidth.  How do you generate =
your
5
> RF frequencies?  If you are using a PC and soundcard, you need a SSB
> transmitter with good linearity vs a simple CW tx.  Or go to a DDS =
chip
and
> a micro-controller (which is what I would do)?


Yes I have done the search and have  found many articles about DFCW.  =
Some
versions seem to use no spacing and only 2 frequencies.
This gets confusing when you have several dots or dashes together along =
with
band conditions fading.  This method seemed easier from the persective =
of
the position of the element determines the value of the element.  By =
using
the 5 freq I was able to eliminate all of the inter element spacing and =
use
only inter letter spaces.  Hence the 4 dots in a row would look like a
squarewave as they alternated between .0, .2, .0, .2
To further decrease the ime to send an ID the inter letter spacing of 1
element could be decreased further and still be effective.

I am using a HP 3856b  selective level meter as the basis for the
transmitter.  These units can easily be locked to a 10 Mhz GPS reference =
and
have a convienient  tracking generator  output on the back at 0DBM in 50
Ohms.  This unit can also be instructed to move in .1 HZ increments.

I alraedy had the HP SLM so I decided to write to it via the HPIB input =
in
the back.  This was a little harder than I thought it would be at first =
and
I still have not master even this small amount of code.  In addition the
element length and dot to dot spacing may leave some room for =
improvement in
clarity.

After getting accustomed to it,  I have been able to read the code =
easily
with out knowing the actual frequencies or spacings of the xmitter.


Did I get everything?   I wish I could post the JPEG I have so you guys
could get a look at it.

Please more comments.  BTW  The "USA"  beacon ID takes 11 min using QRSS =
60
to ID.
W1VLF takes 27 minutes  as apposed to 60 minutes using standar 3:1 QRSS.

This advantage may just put that callsign in the midst of a prop peak =
where
a 1 hour ID would not have survived.

Thanks for the comments.
Would wyou like me to email a JPEG of the USA capture?


Paul Cianciolo
W1VLF
Beacon  " USA"  185.298.00 Khz




> Why use 5 vs 3?  A dot freq, a dash freq and a space freq.  With fixed
> timing formats, we know when the changes are "allowed" to happen, i.e.
RTTY
> runs at a few speeds, right? 45.45, 75, 100 I think.  No one is =
sending at
> 82.3 or 69.1.  If you are on the dot freq 3 time periods, and then got =
to
> space, it is an S.  If it goes to the dash freq for 1 period then =
space,
it
> is a V.  The 3 to 1 and inter-element spacing was for hand keying and
human
> ear decoding.
>
> But yes, there is merit in NOT having dashes 3 times longer than dots =
and
> being able to tell dropouts from element spacing.  What way to do it =
is
the
> question <G>
>
> Gary WA6DTX
> ----- Original Message -----
> From: <paulc@snet.net>
> To: <lowfer@mailman.qth.net>
> Sent: Wednesday, March 19, 2003 7:43 AM
> Subject: [Lowfer] QRSS Alternative?
>
>
> > Hello Folks,
> >
> >
> [snipped]
>


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