Batboard

Just wanted to throw a question out there for you guys to chew on... Do you think it would be legal to put up lets say a 3 channel trunked basic EDACS system? As long as it identifies itself, I don't see a problem with it. The control channel is not encrypted data, and anyone with an EDACS radio would be able to use it. I have enough equipment to make a 3 channel UHF 440 EDACS site. Let me know what you guys think...

i was thinking the same thing but with a pulled from service uhf (410mhz) system.

i know i can get it to the top end of 430 mhz anyway....





d

It may be illegal because you have to be in control of your tx frequency at all times and in a trunk system the computer is in control. I may be off though.

I believe you are incorrect there GEMOTO.

A repeater is allowed to be automatically controlled.

But check Part 97 for yourself, or ask a lawyer.

Chrisjz and batdude: GO FOR IT! Be sure to tell us more.

The FCC has a requirement that we use only the minimum amount of spectrum to communicate, and as someone else has previously stated here on the same subject a trunked system does not meet that requirement.

A trunked system's reason for existing is the ability to have talkgroups, and all you have to do to achieve that on 440 is for different groups of people to use different simplex channels or different repeaters. It ain't quite the same thing as talkgroups, obviously, but it's close enough.

Which leads me to the question of why one would need a trunked system on 440.

Which leads me to the question of why one would need a trunked system on 440.

Why not? As far as I'm concerned ham radio is, for the most part, DEAD on 440. Even 144 can be unusually boring sometimes. Why not experiment? I say go for it, you might as well use the freqs if they're not being used by someone else! If I was in your area and you set up a trunked system, even an EDACS one, you can bet every penny that I'd go out and buy an EDACS radio.

Tom in D.C. wrote: Which leads me to the question of why one would need a trunked system on 440.

One could also ask why people would use IMBE on the ham bands, when analog FM works just fine.

The answer: because one can.

Tom in D.C. wrote:The FCC has a requirement that we use only the minimum amount of spectrum to communicate, and as someone else has previously stated here on the same subject a trunked system does not meet that requirement.

I hear what you are saying Tom... but perhaps look at it from this angle:

Trunking actually increases spectrum efficency, depending on system loading.

If it didn't, we wouldn't have gone from IMTS for mobile phones, to AMPS trunked cellular, right?

Wouldn't you have to ID on each frequency at least once every 10 minutes ?

Johnny Galaga wrote:Wouldn't you have to ID on each frequency at least once every 10 minutes ?

Only active frequencies.

So you would have to keep track of what frequencies your conversation has used within each 10 minute period. Then you have to go and ID on each of those frequencies ?

Johnny Galaga wrote:So you would have to keep track of what frequencies your conversation has used within each 10 minute period. Then you have to go and ID on each of those frequencies ?

Well, yes... perhaps the controller could be smart enough to do that. *puts hands up* I know NOTHING about EDACS!

I'm sure it wouldn't be too difficult to make a homemade device that is connected to each repeater individually that automatically TXes a CW-ID every ten minutes -- that would take the burden off the controller. As far as the control channel, that's where the biggest problem is.

We are also looking into this feat in Metro Detroit Area.
Across the river, OPP has an Astro VHF trunked system.
Jimmy

The GETC (General Electric Trunking Controller) can be programmed to CW ID on every channel (including the control channel) at whatever interval you like. So that would take care of the identification part. I am going to try it and see how it works. I will keep you guys posted on the progress

Chrisjz wrote:The GETC (General Electric Trunking Controller) can be programmed to CW ID on every channel (including the control channel) at whatever interval you like. So that would take care of the identification part. I am going to try it and see how it works. I will keep you guys posted on the progress

Are you running one antenna for each channel? Or a common Rx antenna using a reciever-multicoupler, and seperate antennas for each Tx? Or what?

But what about the other hams ? Let's say you have a round-table or rag-chew deal happeneing, and you've got 3-4 hams on a talk group chatting away.

Wouldn't they each have to stop and ID on each frequency every 10 minutes ?

The invividual person is ID'ing on the frequency being emitted by their radio. That is all each person would need to do. The trunking system would have to give it's own ID on the frequencies it is transmitting on every 10 minutes during use.

nmfire10 wrote:The invividual person is ID'ing on the frequency being emitted by their radio. That is all each person would need to do. The trunking system would have to give it's own ID on the frequencies it is transmitting on every 10 minutes during use.

But the frequency emmited by their radio changes with each press of the PTT, since EDACS uses transmition trunking. I would think that would result in multiple frequencies the user would have to ID on.

Johnny Galaga wrote:

nmfire10 wrote:The invividual person is ID'ing on the frequency being emitted by their radio. That is all each person would need to do. The trunking system would have to give it's own ID on the frequencies it is transmitting on every 10 minutes during use.

But the frequency emmited by their radio changes with each press of the PTT, since EDACS uses transmition trunking. I would think that would result in multiple frequencies the user would have to ID on.

I understand what you're saying, but I really don't think it would be an issue -- at least not a big enough one for me to worry about it if I was putting a system up. Anyone with a basic scanner or EDACS radio would be able to follow the conversation and easily figure out who's who.

And even if it does turn out to be a big deal, the users can be like the Virginia State PD dispatchers and just say their call at the end of [almost] each transmission.

i think this falls under the perview of mr. hollingsworth's comments about IRLP - that as long as it's in the "spirit of ham radio" - (insert unattended IRLP remote base here) then it should be allowed whenever possible.

if i can get the repeaters (all old MSF's) and the controller, you can bet your butt that i might set 2-3 of them up on a trunk.

sometimes it's better to ask forgiveness rather than permission........


d

Trunking on the ham bands has been talked about for some time. If you do a search you will find out about a 900 Mhz ham system that was set-up to do trunking.

It was talked about over here and was set-up using a smartrunk format as you can get a board for just about every ham radio out there.

It was working great for awhile but then it was starting to get used more and more as a cross-link repeater. The trunked system had a conventional cross over to one talkgroup so people could cross communicate.

It then got taken down due to funding and location. The ideal with LTR is being looked at again but it may not be feasible as it seems a little bit harder to intergrate LTR into ham radios then smart trunk.

We checked the rules and talked to many people at the ARRL. About the ID'ing issue and what was told to us was that a repeater had to ID every 10 minutes when the repeater was being used or at least every hour if not being used.

The controllers we used allowed us to set this ID'ing up this way so there was no problem.

The only draw back with other types of trunking is aval of radios as well as trunking formats that use a control channel which takes up a repeater as UHF or VHF for that matter is jammed pack already.

But good luck to you in your efforts.

LTR could work on 900 ham.

There are a lot of LTR GTX portables and mobiles out there.

If anyone wants to try it, I have some 800 hybrid combiners and receiver multicouplers I can let you try. Seriously. They are just sitting on the shelf in the basement collecting dust.

Well, if you're worried about having multiple channels, why not run a SCAT system and just use one frequency?

Kinda pointless, but it'd be kinda cool to be able to call users, etc...

If you're worried about other users not having access...it wouldn't take much at all to have another UHF conventional repeater "patched" into a "general" talkgroup, then have other talkgroups that are more "private", so to speak.

I for one, think it's an awesome idea.

And to answer the question? Why not?

-Mike

[quote="n9upc"]
We checked the rules and talked to many people at the ARRL. About the ID'ing issue and what was told to us was that a repeater had to ID every 10 minutes when the repeater was being used or at least every hour if not being used.

They actually told you this was the rule? Where did this BS come from?

Chris
N9LLO

It is not BS and actually makes sense. The logic is if the repeater is not being used just sitting there waiting to be used they advised that the ID only has to come every ten minutes if there is traffic.

If you normally talk on simplex but have not for an hour or so do you have to go on and ID every 10 minutes? Granted do to the Smartrunk that was being used it did key-up almost every 15 minutes so the controller did ID every 10 min. BUt not to stray from the topic and make a different topic in this one....

...good luck if you are trying it. We did UHF and it worked good. MOst people asked why do this but the answer was simple you can squeeze more people on to a site this way then by having only one repeater channel.
Not to also mention the conventional tie in was a repeater at a different site and was for coverage purposes mainly but never the less it did provide a conv tie in point/access.

quoting n9upc:
"We checked the rules and talked to many people at the ARRL. About the ID'ing issue and what was told to us was that a repeater had to ID every 10 minutes when the repeater was being used or at least every hour if not being used."

If this is specifically addressed at trunking systems, then I'll leave it alone, but if it's for an ordinary VHF or UHF amateur voice repeater station, I would take exception to the last part.

I have no problem with my repeater IDing every 10 minutes when it's in use, similar to the users IDing every 10 minutes when they're using it. But this thing about a repeater IDing every hour if NOT being used? Seems like an unauthorized transmission to me. What licensed ham would initiate this ID cycle every hour? If no licensed ham is doing it, then something unlicensed must be, i.e. the repeater controller, and I don't think the rules allow for such an event. Although it's possible that something new has been added to Part 97, this particular clause seems more than fishy to me. Idealistic for sure, but I don't think it's either legal or required. The big problem will be finding some updated copy of Part 97 and looking very closely at the rules for ordinary stations and repeater stations.

Of course, we could also just go to "the source" and ask Riley directly. I've heard he can be most helpful in these circumstances.

Bob M.

LTR would be a good way to start. At least all of the channel will be used for voice instead of having a dedicated control channel. And let's not forget another good reason to try LTR, COST. You can pick up a LTR controller for pretty cheap compared compared to a small 5 channel startsite controller.

Charles

Quoted/extracted from a text file provided by the ARRL:

"§97.119 Station identification.
(a) Each amateur station, except a space station or telecommand station, must transmit its assigned call sign on its transmitting channel at the end of each communication, and at least every ten minutes during a communication, for the purpose of clearly making the source of the transmissions from the station known to those receiving the transmissions. No station may transmit unidentified communications or signals, or transmit as the station call sign, any call sign not authorized to the station.
(b) The call sign must be transmitted with an emission authorized for the transmitting channel in one of the following ways:
(1) By a CW emission. When keyed by an automatic device used only for identification, the speed must not exceed 20 words per minute;
(2) By a phone emission in the English language. Use of a standard phonetic alphabet as an aid for correct station identification is encouraged;
(3) By a RTTY emission using a specified digital code when all or part of the communications are transmitted by a RTTY or data emission;
(4) By an image emission conforming to the applicable transmission standards, either color or monochrome, of §73.682(a) of the FCC Rules when all or part of the communications are transmitted in the same image emission.
(c) One or more indicators may be included with the call sign. Each indicator must be separated from the call sign by the slant mark (/) or by any suitable word that denotes the slant mark. If an indicator is self-assigned, it must be included before, after, or both before and after, the call sign. No self-assigned indicator may conflict with any other indicator specified by the FCC Rules or with any prefix assigned to another country.
(d) When transmitting in conjunction with an event of special significance, a station may substitute for its assigned call sign a special event call sign as shown for that station for that period of time on the common data base coordinated, maintained and disseminated by the special event call sign data base coordinators. Additionally, the station must transmit its assigned call sign at least once per hour during such transmissions.
(e) When the operator license class held by the control operator exceeds that of the station licensee, an indicator consisting of the call sign assigned to the control operator's station must be included after the call sign.
(f) When the control operator who is exercising the rights and privileges authorized by §97.9(b) of this Part, an indicator must be included after the call sign as follows:
(1) For a control operator who has requested a license modification from Novice to Technician Class: KT;
(2) For a control operator who has requested a license modification from Novice, Technician or Technician Plus Class to General Class: AG;
(3) For a control operator who has requested a license modification from Novice, Technician, Technician Plus, General, or Advanced Class operator to Amateur Extra Class: AE.
(g) When the station is transmitting under the authority of §97.107 of this part, an indicator consisting of the appropriate letter-numeral designating the station location must be included before the call sign that was issued to the station by the country granting the license. For an amateur service license granted by the Government of Canada, however, the indicator must be included after the call sign. At least once during each intercommunication, the identification announcement must include the geographical location as nearly as possible by city and state, commonwealth or possession."

Of note is Section 97.119(d) which covers Special Event stations. THESE stations are required to ID with their assigned call sign once per hour. This may be in lieu of the normal every-10-minute ID requirement. Such stations must apparently register with a centralized database system (which probably hands out a special event callsign) so the FCC is aware of the station and the event. This would probably cover things like Boy Scout Jamborees or other short-term events (i.e. 1-2 days like hamfests and DXpeditions). Also, it would seem that the requirement to ID every hour only pertains to the time the station is actually actively on the air. If it shuts down overnight and is not being used, I don't believe it needs to provide an ID. In the case of an HF station, which frequency(s) would the ID be transmitted on, and by what (person or machine)?

I don't think that a trunking repeater system would be setup as a special event station; therefore it does not need to ID itself every hour when not in use.

For everything and everyone else, the usual ID requirement of every 10 minutes is all that there is. There is a Part 97 section for repeaters, but there are no other ID requirements other than what's in section 119.

I'm not a lawyer. Other than the quoted Part 97.119, these are my own opinions and interpretations. I feel that one must include the INTENT of the rules and regulations when applying them to any situation.

Bob M.

I vote LTR as well. Since it doesn't have a dedicated control channel, your capacity is limited only to your design and controller limits. LTR at 900MHz is a great idea. Combiners can get interesting. Try not to allocate all repeater pairs in your area.

Also, for all intents and purposes, a trunking repeater is a closed repeater. This works to your advantage though, as you know all mobile IDs and if you don't, you can exclude.

I can see a Smartzone Omnilink batlabs system developing out of this.

Who has informatino on controler hardware, how to interface, etc.

I would prefer smartzone, as each mobile/portable I have happens to have trunking in it, but no LTR.

How much M surplus trunking stuff exists.

-Alex

[moved to infrastructure]

Alex, that'd be pretty cool actually.

You can have what...32 sites per "zone" and 3 zones in a SZOL system?

It probably wouldn't even need to be an Omnilink system, even just a Smartzone system. A radio that does just plan Type II Smartnet would work as well, you just wouldn't benifit from the Smartzone features.

I wonder if you could link them sorta how IRLP links repeaters, but it'd be a fulltime link?

-Mike

SlimBob wrote:I vote LTR as well. Since it doesn't have a dedicated control channel, your capacity is limited only to your design and controller limits. LTR at 900MHz is a great idea. Combiners can get interesting. Try not to allocate all repeater pairs in your area.

Also, for all intents and purposes, a trunking repeater is a closed repeater. This works to your advantage though, as you know all mobile IDs and if you don't, you can exclude.

With LTR, ALL repeaters would always have to ID every ten minutes as they all transmit every ten seconds when idle.

I experimented with LTR trunking several years ago on the UHF ham bands. I think LTR is a much better deal (not because of its technical ability) because it doesn't have a control channel. But as someone else mentioned, one issue, actually several issues, revolve around the LTR blips on each channel. Now in theory, a simple IDer would solve the "ID" problem this would create, but there is another long forgot about idea in ham radio that makes trunking a particular issue. "Lock Out Receivers", remember those. Now days nobody probably cares, but before you transmit on any frequency you are "supposed" to insure it isn't being used. In the old days, we would have a receiver at the site to monitor the repeater output, if something was there, the COR on this receiver was used to disable the PTT line on the repeater transmitter. I know, who cares. But, now you have repeaters coming and going all over the band without doing this "legal" check, as well as the mobile radio itself. Have always thought that a good trunked system, especially in a busy area like LA or somewhere would be slick, thus the playing around. Now that I am in montana, I have 5 repeaters and nobody on any of them so that seems to work. But in an area where everything is so busy as to make trunking a really spectrum efficient way to go, then the risk of harmful interference is also just as great. Again, who cares, but, someone might. If we could get repeater channels assigned with more teeth that a local coordinator, and a reversal of FCC practice of "sharing the freqs", then it would be a no-brainer.

Hello.

I think it would be neat to have trunking on the ham bands, but.
Why a type II system, what about making it real simple?
Type I can do everything but system priority and smartzones, and the radios are super cheap.
Would be fun to play with no matter what.

This discussion of having to ID on EACH and EVRY frequency that the trunked
system uses is not really required.

I've been playing with satellites for years now and don't do back and ID across
the frequencies that I transmitted on as I tracked for doppler shift.

IDing would only pertain to the frequency that you are using at the time that
you are transmitting on.

Just my two cents worth...

Been there, done that. An LTR system is in service in Minneapolis and while it doesn't have many users, it's there and no one complains. Besides, even if they did, I would not care anyway.

LTR is the easiest to impliment and work with. Also, my HT1550.XLS works nicely on this system.

George