LF: Re: 475kHz crystal

[Minto Witteveen <minto.witteveen@gmail.com>]

Hi Graham,

It is possible to use the parallel port of a PC to control the DDS, the DDS 
has a 3-wire SPI interface. See for instance: 
http://www.qsl.net/p/pa3ckr//signalgenerator/ . Here you will find (amongst 
a lot of other info) a VB program to control the DDS 
(http://www.qsl.net/p/pa3ckr//signalgenerator/prad9850.zip). But be prepared 
to re-install W95 or possibly DOS because it will not work with newer 
versions of windows….
Using a PIC is the easiest method I think.  Andy already beat me to it, see 
his earlier reply to my mail. If you do not want to make a PCB you can even 
build it using a prototyping breadboard.
Minto pa3bca




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Ceterum censeo Carthaginem delendam esse
-----Original Message----- 
From: Graham
Sent: Tuesday, January 08, 2013 21:16
To: rsgb_lf_group@blacksheep.org
Subject: Re: LF: Re: 475kHz crystal

Minto

Is it possible to communicate  with the  DDS  from the  PC  for  a  simple
VFO or  need  the  pic  ?

G.

--------------------------------------------------
From: "Minto Witteveen" <minto.witteveen@gmail.com>
Sent: Tuesday, January 08, 2013 6:46 PM
To: <rsgb_lf_group@blacksheep.org>; <rsgb_lf_group@yahoogroups.co.uk>
Subject: LF: Re: 475kHz crystal

> 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.
>
>
>
>
> --------------------------------------------------------------------------
> Ceterum censeo Carthaginem delendam esse
> -----Original Message----- 
> From: Klaus Hirschelmann
> Sent: Tuesday, January 08, 2013 12:00
> To: rsgb_lf_group@blacksheep.org
> 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