Or, as long as you are going to use a PIC anyway, order a AD9850 DDS module
from buyincoins.com. This 0-40MHz DDS costs less than $5 (including
shipping). Add a cheap PIC, a $5 2x16 LCD and a rotary encoder (or use your
PC to communicate with the PIC) and you can generate any frequency you want.
And use the PIC to generate Opera, wspr, qrss.
My next project. I already have all the components….
Minto pa3bca.
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Ceterum censeo Carthaginem delendam esse
-----Original Message-----
From: Klaus Hirschelmann
Sent: Tuesday, January 08, 2013 12:00
To: [email protected]
Subject: Re: Fw: LF: 475kHz crystal
Hi Pete and group
maybe we can bring http://www.hanssummers.com/ for also offering
630m-Band versions of his QRSS and WSPR kits.
He doesn't seem to have taken MF on board as far as I can see. May one of
his rigs can be modified I have not checked my self.
He does mention the use of Si570 programable xtal. I have one on a board
with set frequencies from a PIC and selected by binary from a dil switch.
They will not operate as low as 500kc/s so they have to be divided with
either a CD4040 or CD4060 or any other logic divider. However it gives
stable selectable xtal frequencies. In this case it is probably worth going
the extra mile and make up a DSS as the master oscillator which will give
VFO coverage. I think your pays your money and takes you choice as they
say....... hee.
What i intend to do, is building a relatively simple Stand-Alone WSPR beacon
for 630m-Band. Using a Si570 with additional divider seemed to be quite an
expensive solution. So i did order 7611.2 KHz crystal ( there is a company
manucturing crystals according to given frequency ). By using a HCF4060B
oscillator/divider this should give a stable signal around WSPR midden
frequency 475.7 KHz. WSPR signal generation is planned according to
http://www.knology.net/~gmarcus/WSPR/WWVB_WSPR%20VCXO%20Contoller.pdf where
( for use in Europe ) i intend to use DCF77 time signals instead of WWVB.
Suitable PIC program version is made by PE1NWL and available via
http://www.knology.net/~gmarcus/ , while DCF77 receiver module is obtainable
from Conrad Electronics.
Because of later signal division by 16, this conception will require a
multiplication of crystal FSK deviation by same factor. For WSPR this should
result in values around 23.43 Hz which ( i hope ) will not cause any
problem.
So far my plans in the moment, but of course it would be much easier, in
case somebody would offer a kit already doing all i like.
..
Klaus, DJ7OO
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