[TenTec] Scout Frequency Error

[Winston]

I have Ten Tec 555 Scout with a frequency display that reads 100 Hz high on all bands.

Looking at the schematic of the counter logic board, I notice a trimmer cap (4-20 pf) in parallel with the 4.0 MHz crystal in the microprocessor circuit. It is labeled C3 on a pictoral of the board.

Is this the control I would adjust to bring the counter readout to the correct frequency?
If so, could this by accomplished by adjusting it to zero beat while tuned a known frequency, such as WWV at 10 MHz?

I’m not familiar with logic circuits, so wondering if it’s a simple adjustment or something that needs to be done by a technician in a well-equipped shop?

Any help would be appreciated.

73, Winston K4CWQ

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