Re: [softrock40] Osc replacement & DDS input 20M Lite
- Hi Dick,Thanks for your information on adding the ICS501 IC etc. I've just downloaded the datasheet and will see what this chip can do.Thanks for showing us this, 73,Roderick Wall, VK3BKO.----- Original Message -----From: dick_faustSent: Wednesday, June 27, 2007 7:06 AMSubject: [softrock40] Osc replacement & DDS input 20M Lite
Just uploaded a file with info on my 20M lite with an ICS501M oscilator
replacement. The ICS501 tripples the crystal frequency with out the
use of any coils. I completely eliminated the osc and buffer as the
501 directly drives the 74HC74.
Besides the IC only 3 other parts are required 2 - 10pF caps and
a .01uF supply bypass.
If the 10pF caps and crystal are removed a DDS can directly drive the
chip at 1/3 the frequency up to the limit of the 74HC74 capability.
This worked out very well for my FCC-2 which will not go to 56MHz.
The uploaded file is titled "Softrock-Lite with ICS501M.pdf"
Photos on pg2
With all the discussion on DDS today thought this might be appropriate.
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