http://garage-door-hardware.com/delta-radio-controls.html
"Peabody" <waybackK...@yahoo.com> wrote in message
news:L9apd.6463$T02.1932@lakeread06...
> I have a 1972-vintage Sears garage door opener, model 139.654000
> which still works great. But the only remote I have left is
> falling apart, and is no longer dependable, particularly in very hot
> or very cold weather.
>
> The transmitter/receiver system is the old analog type - no digital
> codes at all, just the specification of "carrier frequency" and
> "modulation frequency", and the receiver is powered by 24VAC
> provided from the main chassis. In fact, it appears that the
> receiver actuates the opener mechanism by at least partially
> shorting out its own power supply temporarily.
>
> I have been unable to find any direct replacements for either the
> transmitter or the receiver. In fact, I don't really see any total
> replacements for the transmitter/receiver system that would operate
> using the 24VAC power supply.
>
> Does anybody have any suggestions for what to do? I'd like to avoid
> having to replace the entire opener.
>
>
Yes, I think there are other universal replacement ones available too
that connect via the manual switch on the old system, so they don't
involve the old RF system at all.