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Old February 12th 06, 11:50 PM posted to rec.radio.amateur.boatanchors
Edward Knobloch
 
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Default Hamarlund HX50 crystal Oscilator Question

Paul P wrote:
During the alignment procedure I have found the crystal oscillators dead or
off frequency (as in unable to adjust to spec with in 1khz). The crystals
have a 1962 dates stamp on them. After disassembly, checking, replacing out
of tolerance components and cleaning all of the associated 6AW8 passive
components, I got most of the crystals back to oscillate. Only two would
achieve spec frequency.

Hi,

I wouldn't worry much about the band setting crystals,
you only have a string dial with that rig, so you need
to spot with an accurate receiver if you get near the band edges anyway.

The important crystals are the USB and LSB carrier oscillator
crystals. If they are off frequency, your voice will either
sound thin or bassy.

There is an easy mod to almost elliminate the resting current
of the 6DQ5 during HX-50 standby periods.
The mod appeared in an early-sixties CQ magazine,
and is very worthwhile to reduce heat in the cabinet.

If you'd like, I'll send the info to you directly.

73,
Ed Knobloch