I agree. Leave the reference oscillator exactly at 84 MHz and align the
BFO crystals instead. They are the most likely to be off frequency.
Yes, they must be adjusted in sequence as indicated in the manual.
73,
Bob WB2VUF
On 10/24/2020 11:23 AM, Bob McGraw K4TAX wrote:
The first thing to check is the oscillators on the Transmit Audio/BFO
Board. The procedure is on page 6-65 of the manual. From experience,
the adjustments are somewhat interactive and must be done in the order
as listed. You should go through the procedure at least twice. Be
sure the radio has been on for 1 hr to allow the temperature to
stabilize as the crystals are subject to drift with temperature.
As to the 42 MHz crystal, it may have aged to the point that it will
not be in the range needed. Replacement is the most likely option.
73
Bob, K4TAX
On 10/24/2020 2:54 AM, Peter Ferrand wrote:
I have a new-to-me Paragon 585.
The rig is slightly off frequency from its readout and the best I can
do is adjust the reference oscillator with C1 to 300 Hz lower in
frequency than the 84 MHz it's supposed to be. Ten-Tec specifies this
frequency must be plus or minus 5 Hz at 84 MHz, which is the output
of the frequency doubler.
I tried removing or reducing C2 but the oscillator stops oscillating.
Rather than track down a new 42 MHz crystal, I wonder if anyone with
more design skills than I have can suggest a slight redesign of the
circuit to pull the existing crystal higher.
Thanks.
Pete
WB2QLL
Mount Pleasant, WI
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