MSF5000 mod to pass IMBE

[Pump3]

Hey folks
Looking for info on what is required to make a MSF5000 pass IMBE, I know people on here have done it, but there is no information on what needs to be done....

Any help would be appreciated...

[Pump3]

No one?

Is it secret-squirrel or something?

[motorola_otaku]

No one on here has done a transparent-receiver mod to a MSF that I've ever seen posted publicly. If it were ever done it would essentially be a "Maxtrac mod" repeater on steroids and not much more useful aside from the constant duty PA.

[Pump3]

Thats what im looking for and apparently it's been done...

http://batboard.batlabs.com/viewtopic.p ... f5000+imbe

[motorola_otaku]

2003 eh? That would explain why it never crossed my radar.

If I had to guess, I would say it entailed bypassing the audio processing circuitry on the CXB SSCB. Probably wouldn't be too hard to do provided you had a schematic of the SSCB.. neither of my MSF service manuals do.

[d119]

I believe Harris or Raytheon makes a P25 base station controller that you could interface to an MSF 5000 and end up with a P25 machine. This way it wouldn't be a "transparent" repeater and would use actual signaling. Of course, the price of said controller is undoubtedly more than the cost of a used Quantar...

[motorola_otaku]

Of course, the price of said controller is undoubtedly more than the cost of a used Quantar...

Raytheon makes it, and last time I looked the pricing was on par with a new Quantar.

[wavetar]

Try PM'ing The Pager Geek, hopefully he'd have the notes from when he did it. I suspect otaku is correct & that it pretty well involves feeding the RX output directly into the TX, perhaps with a manual control for deviation setting.

Todd

[Pump3]

I did PM him before I posted this with no response...

Thanks for the help so far guys

[kcbooboo]

The MSF5000 secure card interfaces directly with the TX, bypassing all the audio processing. It essentially goes directly to the VCO. The raw discriminator-output RX signal also feeds the secure card. Chances are, all the signals you might need can be found on the secure connector on the SSCB, although you may need to move a few jumpers to get the signal path to go the way you want it, around all the analog stuff.

Bob M.

[The Pager Geek]

Never made a cute chart for it.

From my notes:

TLN3189A SSCB (CXB)
Step 1:Program for station for CSQ operation.
Step 2: Remove C8119
Step 3: Run a jumper from J801 Pin5 to Pin6 of U831.
Step 4: While transmitting a digital signal to the input, adjust the output deviation via RSS to 3.0Khz (2.83Khz) on the output.
Step 5: Verify clear analog is approx 4.8Khz

Done.

This will pass everything. Analog, Digital, Securenet (assuming it has a transparent secure board in it), noise, etc. Just like the maxtracs, only it passes 12k securenet where the maxtrac will not.

Good luck
tpg

[motorola_otaku]

Have you tried D-STAR or VSELP through it? I would assume VSELP works since it also runs on C4FM.

[Pump3]

Thank you very much!

[The Pager Geek]

Have you tried D-STAR or VSELP through it? I would assume VSELP works since it also runs on C4FM.

VSELP no issue. Not sure about DSTAR