Home » Ham Radio » Radio Mods » Motorola MaxTrac 900 Ham Conversion
| Motorola MaxTrac 900 Ham Conversion [message #23] |
Mon, 22 August 2005 00:23  |
kc2nda Messages: 26 Registered: December 2004 Location: New Paltz |
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I am looking for some information to convert a Motorola MaxTrac 900 to be able to use it on the Ham band. Can anyone offer any help?
The model # is: D27MWA5GB7AK
Thanks in advance.
KC2NDA
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| Re: Motorola MaxTrac 900 Ham Conversion [message #24 is a reply to message #23 ] |
Mon, 22 August 2005 00:31   |
root Messages: 99 Registered: December 2004 |
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I do not know if this will help, but stumbled accross this on the web:
\\\"Motorola MaxTrac Lab Motorola FM 900 902 conversion
es 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 pbass 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 the 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.
I am working on Spectra but not sure if this radio will make it. Anyone that has info on the Spectra please contact me.
Dean
dbm@cats.njit.edu
5/30/92
Maxtrax 900 Ham Conversion
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 on next page.
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.
Motorola Maxtrac 900 VCO
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:.......................:
: --//--........--//--..:
:..(RX)........(TX)...:
:.......................:
:.......................:
:.......................:
:.......................:
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:.......................:
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.
[Updated on: Mon, 22 August 2005 00:32]
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| Re: Motorola MaxTrac 900 Ham Conversion [message #110 is a reply to message #23 ] |
Tue, 06 March 2007 22:03   |
celes_maxtrac Messages: 13 Registered: February 2007 |
Junior Member |
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Any idea how much that software is?
__________________
Motorola Maxtrac Series Parts List - Download the Maxtrac Series Parts List Catalog by Motorola
[Updated on: Tue, 06 March 2007 22:07]
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| Re: Motorola MaxTrac 900 Ham Conversion [message #111 is a reply to message #23 ] |
Tue, 06 March 2007 22:05   |
celes_maxtrac Messages: 13 Registered: February 2007 |
Junior Member |
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hi
[Updated on: Tue, 06 March 2007 22:07]
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| Re: Motorola MaxTrac 900 Ham Conversion [message #112 is a reply to message #23 ] |
Tue, 06 March 2007 22:08   |
celes_maxtrac Messages: 13 Registered: February 2007 |
Junior Member |
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hi
[Updated on: Tue, 06 March 2007 22:12]
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| Re: Motorola MaxTrac 900 Ham Conversion [message #119 is a reply to message #23 ] |
Sat, 10 March 2007 00:31   |
root Messages: 99 Registered: December 2004 |
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Maxtrac Firmware list
Part number,application, version, checksum, date, chip
HLN9277A, VHF/UHF/800 Conventional 5 pin logic board, 4.00,(n/a), 1987, 27C64
HLN5569A, VHF/UHF/800 Conventional 16 pin logic board, 5.34, (n/a), 1987, 27C256
HLN9435A, 800 Trunked 16 mode w/conventional, 54.03, (3FD0), 51/92, 27C512
HLN9260C, Maxtrac 840 5 pin boards, 52.07, (n/a), 1987, 27C256
HLN9383F, Startsite Smartnet Type2 16 pin, V71.25, (BEB3), 22/95, 27C512
FRN4007B, 900 Trunked, V80.08, (44F3), 51/94, 27C512
FVN4019A, 900 Conventionl, V30.03, (BD00), 21/98, 27C256
FLN6531A, 800 Desktrac, V31.00, (90D0), 14/95, 27C256 (Tx & Rx are same)
5102901S02, Intrac UHF Maxtrac, V IL 1.014, (n/a), 1990, 27C256
HLN9499B, Radius M214/216 16 pin bd, 21.01, (n/a), 1987 1991, 27C256
Logic Boards
Low Band, VHF, UHF, 800
HLN5172A, 5 pin, trunking
HLN5173B, 5 pin, conventional
HLN9123A, 5 pin, masked
HLN9313A, 16 pin
900 MHz trunking and conventional
FRN5529A, 16 pin
800 RF boards
HLF4095B, non-talkaround
HLF9122A, talkaround
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| Re: Motorola MaxTrac 900 Ham Conversion [message #127 is a reply to message #120 ] |
Tue, 10 April 2007 07:04  |
matt07 Messages: 3 Registered: April 2007 |
Junior Member |
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Hi, root! I think I'm gonna check out that link. Thanks.
______________________
matt07
Alcoholism Intervention --Learn more about alcoholism intervention options
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