modify 800mhz motorola

[Batman]

i seem to recall 800 spectra's being able to maker use of system watch software. has anyone ever thought of or tried to mod any motorola radios to use 3rd part trunking software such as E or M trunk?

seems to me it would be a legal way to use a commercial radio on a TRS and avoid legal hassles.

i'm sure it would require replacing the controller board with something made from scratch that would allow trunker software to change frequencies, etc.

i know i have a reputation for thinking up crazy stuff that often annoys most people, hope this isn't one of those times again.

was just an idea that popped into my head this morning.

[thebigphish]

This sounds like a LOT of work, and a lot of R&D time, and then a LOT of parts...all of which would surely pale in comparison to the cost of a uniden scanner.

If you're replacing the controller board on a portable to "something made from scratch" you can pretty much throw out the PA, crystals, microprocessors, filters, eproms, etc at this point, because you probably aren't going to be able to make something work with them. Then you're talking about a "legal way to use the case and antenna from a commercial radio on a TRS and avoid legal hassles.", which doesn't seem like a very good use of resources anyway.

Scanners don't affiliate, scanners are easier to program (in some instances - ha!), scanners have orders of magnitude of more spectrum coverage, and scanners are easily available to the end user.

It just blows my mind why there is this impetus to use (in most cases) a non-system issued subscriber unit on a closed radio system.

We already have enough trouble with moto blowing a gasket over RSS and radios with dubious S/Ns (hey Nick, still reading?), so why reverse engineer a unit just to do what a scanner can do

dunno. i just don't get it.

btw. Bob, i'm not trying to sound like a dick, sorry if it did.

[Batman]

because scanners suck. even expensive ones. shitty audio from small speakers, bad rejection in a dense rf environment. in short the sensitivity and selectivity and received audio of a commercial radio will far exceed that of a scanner.

[RADIOMAN2002]

I agree, I modified a number of UHF Spectra's to listen to FDNY and Westchester County FD. Much better audio handles the simulcast distortion better too. I would look at possibly modifying the Motorola firmware to decode the rebanded 800, before trying to make a controller ala an Autorino. I havn't had the time to do it, but I'm sure it is possible with bitbanging.

[thebigphish]

Not going to dispute the obvious...obviously, yes the RX path is superior to that of a scanner, as they can create a more selective front end for said radios, as they only have to specify a narrow subset of the emissions band.

Good luck in your quest.

[DPL]

Some guy on radioreference was working on something like what you're talking about with an 800 Maxtrac and an Arduino board. See http://forums.radioreference.com/motoro ... plant.html. I haven't actually read the whole thread, but I think he actually got it working on some level. The funny thing was that when he was talking about it beforehand everybody was like "why would anybody want to do that?" and then when he actually did it everybody was like "wow, that's cool."

[motorola_otaku]

Some guy on radioreference was working on something like what you're talking about with an 800 Maxtrac and an Arduino board. See http://forums.radioreference.com/motoro ... plant.html. I haven't actually read the whole thread, but I think he actually got it working on some level. The funny thing was that when he was talking about it beforehand everybody was like "why would anybody want to do that?" and then when he actually did it everybody was like "wow, that's cool."

That is a great topic and definitely a step in the right direction, but the two big problems with that setup that would deter a lot of people (myself included) is no 700 MHz and no P25. Even if you could somehow replicate that setup using 700 CDMs you still wouldn't have P25 decode.

My dream product is a SDR-based device with multiple demodulator/receivers.. let's say five. Since a SDR is capable of watching big chunks of spectrum all at once it could simultaneously handle control channel and voice channel receive, with the individual receivers handling the D/A conversion and voice channel decode. The control channel and P25 voice data streams would never need to leave software. Such a device could conceivably handle UniTrunker-like functions like tracking of individual RID affiliations while performing normal talkgroup scanning at the same time. Combine that with a brick-wall 700/800 hardware bandpass filter and you would truly have the King Of Trunktrackers.

But coming back around to what the OP is wanting to do.. the "why" for me at least would be compactness and ease of operation. I'm not going to install a computer and a stack of modified Maxtracs in my car just so I can listen to the local fuzz without losing the trunk every time I get with a quarter-mile of a cell site. For a mobile installation you absolutely want an everything-in-one-package device that programs and acts like a normal radio. On top of that, your hardcore business/mission-critical listeners -news rooms, towtruck operators, fire restoration companies, even public servants who need to listen to other channels or agencies for mutual aid purposes but can't obtain a "real" radio for whatever political BS reason- aren't going to have the technical expertise, patience, or train-ability to operate a kluge of computers and radios. They want something that installs, looks, and acts like a mobile radio and can't be FUBARd by fat-fingering the controls. There is a whole niche market there with deep pockets that isn't being serviced by anyone. Of course, this would all be a moot point if Motorola put an actual no-affiliate transmit inhibit option in their programming like Harris/MA-COM/GE has had in EDACS for years, but that's a whole other discussion..