[Motorola] old Monitor receiver

[Gary Chatters]

>
>      I recently acquired an old Motorola monitor receiver (tube type) and was wondering what frequencies these may have operated on.  I don't have the unit just yet but do know that it is a model #LO3F-2 and it has at least one crystal on 9103.823 possibly the IF. I want to turn this unit into a dedicated receiver for either 29.6 or 52.525 since I believe these may have been designed for low band.
>

Quite a few years ago I had an L03 monitor receiver.  I don't know
if this would be the same model or not.  The one I had was built on
a chassis about 8" X 10" x 1.5" and had a bunch of miniature tubes.

As Glen mentioned, the L03 is a high band receiver.  I don't recall
what the subranges were.  To see if it is working you can feed a signal
generator in to it and see what it picks up.  Based on the crystal
frequency I am going to make a wild guess that it is tuned to 155.220MHz.

I set mine up to monitor 146.76.  I don't recall having to do any
conversion work on it, but that was a long time ago.  There was some
problem with the crystal I got for it.  Take a look at the crystal
and see if there is a type number on it.  If so, you can probably
just order one based on that and the channel you want to listen to.

There are two peculiarities that about this receiver:

You need to have it mounted in a cabinet that shields the chassis.
If you don't  the approximately 9MHz IF will pick up shortwave
broadcast quite well.

It is dual conversion and uses one crystal for both conversions.
Thus the second IF is not fixed, but depends on the receive frequency.


73,
Gary