Need Info: Motorola Mod

Need Info: Motorola Mod

Post by John Voigt India » Wed, 07 Dec 1994 02:35:28

I would greatly appreciate any information available on the conversion of a
VHF Motorola Micor receiver and/or transmitter for use in the 220MHz band. I
have heard form several sources that this conversion can be done, but I haven't
been able to find out how yet.

-Thanks

John Voigt

N9IAH
--
John Voigt

N9IAH

 
 
 

Need Info: Motorola Mod

Post by John Ackerma » Wed, 07 Dec 1994 07:10:59



Quote:>I would greatly appreciate any information available on the conversion of a
>VHF Motorola Micor receiver and/or transmitter for use in the 220MHz band. I
>have heard form several sources that this conversion can be done, but I haven't
>been able to find out how yet.

I don't have the step-by-step instructions available, but years ago we
converted a number of VHF Micor RXs to 220.  All you need to do is open up the
helical resonator and remove 1/3 of the winding from each coil.  Then, do some
tweaks to the LO and injection chain (if you use low-side injection, it won't
take too much) and you're finished.  We got sensitivity about equal to that at
VHF, and very good front-end performance.  (Of course, if you want to use the
optional preamp, you have a bit more work to do.

The transmit can also be done, so I'm told, but in our group we never got
further than getting the e***r to work.  On at least one repeater, we used a
modified e***r and e***r sc*** to drive a Midland 13-509 final, and
that worked pretty well (and was much cleaner than the Midland e***r).

John  AG9V