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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