Yes the Maxtrac will work on the 900 ham band. However the Spectra is much harder.

I have one Maxtrac converted and while getting to work took quite some time the final mod is not that bad.

Conversion:

Start with a 900 Mhz Maxtrac. If is is conventional then fine, if not then order FVN4019A conventional firmware.

You will also need to order two Murata filters (# DFC3R915PO25BTD) from a Murata Erie dist in your area.

Locate two chip caps with a value of 1.1 pf. Install firmware if not already conventional. Remove the two Murata

filters in the front end and replace with the above so that the radio will pass 915 +- 12.5 freqs.

Locate the VCO and using a LARGE solder iron heat the top cover and pry it off. Now looking into VCO you will

see that the small board has components on left and right halfs and they are a mirror of each other (the left and right).

Looking in two corners you will see chips with chip diode directly under it. It is very very tight in this

Remove these two chip caps that are next to the chip diodes. Replace with 1.1 pf caps

*** NOTE: The value of these caps might vary -- you may have to put anything from 1.1 to 1.9 pf in -- DO NOT

use too much solder when installing caps. It is very easy to damage the VCO!!!!

Now put everything back together. I have mine operating with a RX area of 920 to 921 and TX of 907 - 909.

Programming of the radio will require Maxtrac conventional software and when the program tells you the frq you

entered is out of band disreguard it and continue.

Maxtrax 900 Ham Conversion 5/30/92

Confirm that your radio had firmware FVN4019A. If not order this from Motorola (510291S04).

Using Motorola MAXTRAC (conventional) software program ham freqs into radio. Software will warn that

freqs are not authorized, press F2 to continue entering ham freqs. Once this is done perform VCO mods

After radio is programmed and VCO mods made radio should have rated TX power but poor RX sens.

This is due to the two 932 Mhz filters in front end. Replace FL1 and FL2 with Murata DCF3R915P025BTD filters.

This will correct the condition. Note: You will be working with CMOS!!!!! Use Caution!!!!!

VCO and Filter MODS are made on RF board. Firmware chip is U804 on Logic board. Maxtrac software can

be bought from Motorola or a local shop with software can program radio.

RX VCO Mod

Remove RX cap, Remove TX cap, Place TX cap in location of original RX cap.

(Note- You may be able to leave orig RX cap in place and add a large amount of solder to right side

of cap while metering Steering Line voltage. Add solder until S/L voltage is in the area of 7 volts when radio is

on your highest receive ham freq).

TX VCO Mod

After removing TX cap place a 1.7 pf cap in it's place. If this value is not available you may place a high

stability variable cap of .5 to 4 or 5 pf in this place. If a variable cap is used you may have to use metal tape

to make a cover with a hole for the cap to fit. Use as little solder as possable on the TX side.

You should have a S/L voltage of no less then 2 volts while transmitting on your lowest freq.