Re: LF: 475kHz crystal

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

Hi again Dimitrios

 

Further more if you dig out those old disgarded PMR RX xtals and look you may be lucky like I think third over tone in the range of 45.312 to 45.984mHz made to oscillate on fundemental at 15mhz frequencies. They will not be exactly a third of the frequency before the SA's say so but allow a 1kc/s / 32. Vincent has the following:-

 

45.3333MHz HC50/U wire end, 3rd O/T, Ser Res, Std Freq Stab ... £4-25/unit

45.452MHz HC49/U wire end, 3rd O/T, Ser Res, Std Freq Stab ... £4-25/unit

45.90MHz HC49/U wire end, 3rd O/T, Ser Res, Std Freq Stab ... £4-25/unit

 

I was lucky to find some in the junk box for the old 501/4 so never chuck xtals away they laid in my box for nearly 40 years.....hee.

 

The new band is difficult because any thing below 8megs (div by 16 ) are like hens teeth.

 

Thanks for flaging this up real ham radio not your ready rolled ham radio well done!!

 

73 es GL es HNY Pete M0FMT IO91UX

From: Dimitrios Tsifakis <dtsifakis@gmail.com>
To: rsgb_lf_group@blacksheep.org
Sent: Monday, 7 January 2013, 5:24
Subject: LF: 475kHz crystal

Hello LF/MF group,

I though this may be of interest to those what would like to build the
simplest transmitter possible for MF.

I found these cheap crystals on eBay:

http://www.ebay.com.au/itm/2-PCS-15200-KHz-HC-49-U-X-TAL-Bargain-Pack-HC49U-/320828846717?pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item4ab2e3b27d

They are 15200 kHz which can be conveniently used with a 74HC4060 to
make an oscillator, then connect to the divide_by_32 line for a nice,
stable 475 kHz signal. You can then drive a class-E FET PA for any
kind of power you like.

73, Dimitris VK1SV