Alex,
Let me correct my e-mail concerning your crystals. I wrote that the 35.304 MHz crystal should work well, and then I calculated the results for a 35.4 MHz oscillator. What I should have said is that the 35.304 MHz crystal will give you a center frequency of about 8.825 MHz. Your IF of 8.83 MHz allows a tuning range from -29 kHz to about +4 kHz and still avoids that big noise spike in the middle of the SoftRock's tuning range.
73,
Tony KB9YIG
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----- Original Message -----
From: "Alex, VE3NEA" <alshovk@...>
To: <softrock40@...>
Sent: Wednesday, September 28, 2005 2:16 PM
Subject: Re: [softrock40]
I ordered two crystals, 35.208 and 35.304 KHz, from Surplus Sales of
Nebraska () about a month ago, they are saying
the crystals will arrive in a few days. The idea is to make one of those
oscillate at 8817*4 KHz and to put SR40 inside my TS-570. The 8830 KHz IF
signal will be pulled from the socket for the extra filter, and SR40 will
replace the IF/AF part of the transceiver.
What is the best way of pulling the LO frequency 36 KHz down or 60 KHz up?
Is this possible at all? If not, I will have to switch to the 96 KHz
sampling rate and use the 35.208 KHz crystal at its nominal frequency. Of
course, 96 KHz is an overkill since the bandwidth of the roofing filter in
TS-570 is 14 KHz, according to the Service Manual.
73 Alex VE3NEA
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