Motorola Trunking

[batwing4ever]

I have a collection of Systems Saber I's and Systems Saber III's and all are low-split UHF. As an experiment, I'm thinking of building a trunking system for ATV audio in the lower ATV sub-band (420MHz-432MHz) of the 70cm band.

I know how trunking works, but I have no clue as to how to assemble a trunking system. Can anyone recommend where to start reading and what /\/\ components and what not, are used for trunking.

[Grog]

I think one thing that has been an issue is a control channel for a moto system. A single freq LTR system might be doable, but not with systems sabers of course.

[batwing4ever]

The Systems Sabers wouldn't be the trunking repeater/base, but the HT's in the field.

[Grog]

Yeah, I know. I should have stated I was referring to the concept of hamband trunking in general, and the legal parts of that.

[MTS2000des]

A few of us in the ATL toyed around with the idea of putting up a 900MHz TRS, given the availability of 900 gear since turdtel took over the band.

The general conclusion is it was a WAFWOT (What a friggin waste of time) because:

1)- ID requirements, all repeaters in the system would have to ID every 10 minutes of use, including the control channel. No provision in Part 97 for control channel based trunking.

2)-we'd have to legally buy the system key for our system from Motorola to keep it on the up and up. Would they sell a system key for a ham system? yeah right! they won't even sell Pro series CPS to PAYING commercial customers...their general piss on hams attitude would certainly be an emphatic NO.

3)-this may not be an issue on ham systems, but on 800/900 the bands are channelized (hence why the rebanding scam plan is such a PITA for Motorola trunked radio users, as the entire 800 and 900 band are pre-mapped channels requiring firmware upgrades) and it would take an SP of the MTC3600 controllers, repeaters, subscriber units, etc to be able to accept a new 927 ham band plan. Likelihood of that happening see answer to number 2.

4)-combiners, mutlicouplers, etc. Even a basic 5 channel Startsite system means 5 repeaters and a ton o' hardware. And you thought Icom wanted a king's ransom for D-Star!

The biggest and most obvious reason is WHY. Around here all the VHF and UHF bands are pretty darn near quiet most of the time. No problem finding a great number of vacant repeaters to chat on. Even after ironing out all the technical issues, you'd likely have a trunked system that would be highly underutilized. The entire point of trunking is allowing a large number of users a small number of resources. We have a small number of users with a large number of resources. Ergo, trunking on ham is a WAFWOT.

D-star or P25 makes alot more sense and does a whole lot more.

[Grog]

Well thought out answer, I'm going to save that for future reference as I just sound like an idiot when I try to explain it

[MTS2000des]

If anything Grog, LTR would be the best choice if one did want to play around with basic of trunking on the ham band. LTR radios are cheap and available from everyone (even Ma M), and LTR controllers are cheap. Since no central control channel is used, repeaters can be programmed to ID at 10 min intervals. While you don't have the coolness of Moto trunking with Private call/page, etc, it could be done a lot cheaper than Smartnet/PP, but the biggest reason not to is unless you get a ton of people with radios, your system will never trunk.

Around here D-star is taking off and with prices dropping it is alot more attractive. D-star is neat, digital and wide area. One of the Atlanta Radio club guys who is heavy into D-Star (AA4RC, Robin Cutshaw) gave a killer presentation on it at their meeting a couple weeks ago. He also has developed a D-Star USB dongle that will access the D-star gateway from a PC, written software to encode D-Star packets, and is currently working on an open source gateway software that overcomes some of Icom's limitations and hurdles.

Analog trunking, heck even P25 phase I seems so "1990's" compared to the realities and possibilities of D-Star.

[AEC]

And to add to the fray......

Systems Sabers will NOT do LTR format, so the use of these radios is out of the quwstion.

E.F. Johnson used to produce controllers that could be integrated into just about any radio system, provided you had the board installed in the radio.

From the controller, to the ID logic, you could assemble a reasonable LTR machine, but once you add channels, you add to the cost due to the need for transmit combiners and receiver multicouplers and more...NOT a cheap alternative.

Even an LTR system with one or two users will trunk, especially if one user keys and unkeys fast, then the system will trunk to that channel and when the second user quick keys, he'll trunk to the next logical channel and so on...

LTR use on amateur radio is pointless, you have elevated maintenance costs, larger power budgets and no real benefits if that systems remains dormant for several hours a day.

Not a wise expenditure of finances I would think.

[bernie]

My two bits worth:
Motorola trunking, AKA "6809" trunking.
The later Start Site Controller will do 1 channel trunking.
In other words this controller will drop the control channel and become a single channel repeater.

The MSF CXB, or the CLB with trunking module can be programmed for trunking provided it has a trunking board board.

I have no idea what the FCC would say about a control channel in the ham band.

An interesting, potentially expensive idea.

[CAPTLPOL]

So has anyone put up an LTR trunk site since the consensus was not to bother with a Motorola site?

[wavetar]

So has anyone put up an LTR trunk site since the consensus was not to bother with a Motorola site?

For Ham use, or just in general? I've put up several, using everything from MSR2000, GR1225, MTR2000 & even Kenwood TKR850. All have been done with Trident Raider or Marauder controllers. Hook-up is generally straighforward, and the systems work pretty well problem free once they are installed.

Todd

[CAPTLPOL]

For Ham use.