Re: Fw: LF: 475kHz crystal

[M0FMT <m0fmt@yahoo.co.uk>]

Hi Again Klaus and group

 

Just got in from a nice ride (burn) on my motorbike beautiful day here.

 

Yes agreed about the kits likewise I was hoping Softrock would do a 136/500 trx they almost got there but their Beta tester let them down otherwise I would be building right now. 

 

Johan Bodin SM6LKM has done a keyer pic based for wspr TX and I built it several years ago. Same principal you described the four shifts had to be set independently to suit the xtal division like you 16 times. I still have it and on close circuit testing it worked OK then I damaged it don't know how so its in the box of " I'll fix it some time projects" !  You are right about the Si570 costing, it builds up for a simple stand alone project as does the DSS so a cheap xtal takes a lot of beating so long as the band allocation is stable as it probably is now. For 500 I have quite a few old 2m x18 xtals from the 1960s (never throw anything away... hee) which divided on to 501/504 but not so lucky this time so have to spend money now.......:-(

 

We need some cleaver guys to generate some interesting MF kits?

 

Thanks for the info and please report back there are people who still build their own and like to hear about others who do.

73 es GL Pete M0FMT IO91UX

From: Klaus Hirschelmann <k.hirschelmann@kabelmail.de>
To: rsgb_lf_group@blacksheep.org
Sent: Tuesday, 8 January 2013, 11:00
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