DeskTrac (MaxTrac) 800 MHz Repeater Receiver

[kcbooboo]

The DeskTrac manual says that Motorola makes an 800 MHz REPEATER that receives 806-821 and transmits 851-870.

The standard MaxTrac mobile radio receives 851-870 and transmits 806-821. These use the HLF4095 or HLF9122 RF boards that have 860 MHz bandpass filters in them.

There has to be another RF board that Motorola used in the DeskTrac radios for 800 MHz repeater receivers that would have different front-end filters. The MaxTrac Detailed Service Manual (W84) has nothing in it about such a board. The DeskTrac manual tells you to refer to the W84 manual for servicing. It does show two radios: an 806-821 receiver and an 851-870 transmitter, so they obviously had it at one time.

I spent 40 minutes talking to Motorola Parts ID this morning and that got me nowhere. I didn't have much faith in the guy doing the research however. If I had a board number or a radio number, that might have helped. According to info I already have, the radios should be D35MJA7DA5AK, which is a standard 800 MHz 15w model number.

I'm assuming they use different front-end filters and program the existing VCO to use high-side injection. No other changes should be necessary but there's also different radio firmware for this application.

Does anybody have an 800 MHz DeskTrac repeater that they can get the RF board number from?

Does anybody have any documentation for this rather unique board: parts list and/or schematic?

Thanks.

Bob M.

[MSS-Dave]

Hi Bob....

There is a possibility I have some info but I will have to look for it (read: go to the bottom of the stack in the garage..). I used to maintain several for a hospital that were on 855.xxx conventional with a TRC option. I had to send a couple off for repair due to lightning and I may still have the service order but it would be at least 7-8 years old. Hopefully, someone can come up with info faster than me......

Dave

[xmo]

What you are looking for is: FLF5543A, RF Board, Desktrac - this shows on MOL as: "Item has been canceled"

FL1 and FL2 on the RF board are Murata Gigafil # DFC3R815 or equivalent from FDK or Toyo. These are also NLA from Motorola and haven't been available for more than 5 years.

The 800 MHz Desktrac uses unique firmware. With that firmware you can enter the receiver input frequency directly using the Desktrac RSS.

See the firmware list at:

http://www.repeater-builder.com/maxtrac ... intro.html

[kcbooboo]

XMO: thanks. That's what I was looking for. I figured everything was NLA and I wasn't trying to build, buy, or obtain such a board.

I wonder where you found that information, as it's not in my Detailed Service Manual (W84). Did they use the same VCO and just use high-side injection with the VCO's talk-around range selected? Were there any other parts differences?

If this came from a manual (which I'm sure is also NLA), can you give me the title and 68 number, or would you be willing to make copies of the few sheets that deal with that board?

Thanks.

Bob M.

[xmo]

Hi Bob,

One of our agencies purchased an 800 Desktrac repeater some time back. I have a file containing all documentation that came with it including the build sheet, packing slip, operator's and service manuals, addendums, etc. There wasn't any supplement for the RF board. When the question about the filters came up here several years ago I did as you did - I called parts ID. Back in 2003 you could still order the RF board but the filters were NLA.The parts ID guy was no help with a part number for a manual supplement.

There are some old threads here from that time that discussed the 800 Desktrac repeater receiver. One poster claimed that he knew somebody that told him they had an RF board supplement but as far as I could determine no one ever posted a part number for it - so maybe it exists but that's as far as I ever got.

[MSS-Dave]

Bob...

Can't find anything on those 800 desktracs now, just MSF 5K I did for that customer, sorry. Anyway, xmo has way more 411 on this stuff than I could ever have....kind of like a Batboard time capsule

Dave