Hamtronics R Series Crystal Receivers

Concept:
From the factory, the squelch action of the Hamtronics R Series receivers have too much hysteresis built in for most peoples liking.  This can easily be changed by referring to your manual for your specific receiver.

Hysteresis is the amount of change needed in quieting between when the squelch opens to when it closes.   From the factory with the squelch set normally, too much quieting is necessary to open the squelch, at least for my liking.  I prefer to have the open and shut points closer together.   The values stated in this article give about 3 dB of hysteresis; which is more appropriate for repeater service in my opinion.

Modification:
On a R144, R220 or R451 crystal sets,  the value of R 25 can be changed up in value to achieve less hysteresis.
In older sets I have had luck with the value of 1 megohm when the original value of R 25 was 330 K.

Newer models use a lower resistance for R 25 and the value of 3 times the original can be tried.
Again, The value of R 25 can be adjusted to suit your personal needs.

This circuit modification was derived from information from the various manuals by Kevin Custer W3KKC, July 2000.

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