Batboard

Okay, Here is a brain tickler. I know that there is a correct product out there to suit the need (astro tac comparator) but if any one is willing to donate one please speak up. With this in mind, here goes the question.

We have a hypothetical qunatro running as a repeater with mixed mode set up. We still want to keep mixed mode working, However we would like to hook up a spectra tac voting comparator to the analog side.

We would accomplish this using two voting sites plus the repeater reciever. The spectra tac has the keying module in it and I gues would get hooked up through the wire line and would key the rptr and pass audio through that. I would also assume that we could get the audio signals from the rear of the qunat for the "in cabinet" reciever. The two other sites would be using gm300's as the recievers and the same on the remote site end.

Here is the problem. I would assume that we than would have to program the quant to be a base station and the comparator would act as the "controller". Are we now going to disable the ability for the quantar to pass and repeater digital b/c it is set as a base station. Does any one have any insight on this situation.

Thanks, Rob

I don't think you can get there from here.

Well maybe.

First, you will need a hypothetical DIU to go along with your hypothetical Quantro.

Program the Quantro for two channels. Channel one would have an access code table for digital repeat through the Quantro. Channel two would be analog transmit. Channel switching would be done by the DIU programming.

The voter would connect to the console port of the DIU. When it votes it will key the DIU which will switch the Quantro to analog transmit.

You probably will need a second receiver at the repeater location. You probably can't work enough magic with the RSS to get the Quantro to do it all. Split the rx feed after your duplexer. If the site is quiet enough you could put a bandpass filter and preamp ahead of the splitter.

Get real Spectra-TAC receivers. GM mobiles don't do status tone. You would end up having to hack either the receivers or the voter. Do it right. Surplus receivers are cheap these days.

Whoever configures this baby and gets all the Quantro & DIU programming right will earn a Batlabs Astro-wizard merit badge.

Hello Rob,

My first statement is "never assume anything." It appears you're trying to to avoid purchasing the correct Astro-Tac Comparator and the Astro-Tac Mix Mode receivers as these are the pieces of equipment you'll need for your Quantro Astro CAI (Common Air Interface) repeater station used in a Voting system for Analog & Astro APCO P25 Type 1 signaling.

There are three (3) types of /\/\ comparators.

1) Spectra-Tac T1786B Analog only with options. Product Cancelation 2005
2) Digitac Q298_A Series Analog (formerly 12Kb Securenet) with options.
3) Astro-tac Series Analog & Astro/Astro-Secute (Digital)

The Oldest Spectra-Tac and next generation Digitac comparators requires a 2175 Hz Status Tone sent down the Telco wirelines to establish a link between the Satelitte receivers and the Analog comparators. The receiver audio's AGC is controlled by the satelitte receivers on the 600 Ohm wireline to the comparators where it is detected and used. Both comparators select the best signal to noise ratio (voting) and send that Analog signal on to the Base Station Repeater for rebroadcast using the C175 Analog Tone Keying options.

If your system does not have a Console interfaced to your current repeater, it is considerered to be a non-wireline system so first one in has the priority. If your system has a console dispatch connected via a Telco or Microwave 2-wire or 4-wire configuration Backbone, you have Console Priority over the Subscribers units on the repeater system. Perhaps your Console has a DIU interfaced, this takes the Analog audio signaling converts it into Digital signaling for Astro signaling out over the air and converts the Astro signaling back to Analog on receive.

The Quantar / Quantro (Obsolete) / Quantar High Power Booster (HPB) RF Amplifier are transparent Infrastructure Base Station / Repeaters as nothing is decoded in the stations, everything is decoded in the DIU or the Subscriber units.

Although the GM300 mobile Subscriber might be used as a Satelitte receiver in non /\/\ systems, I do not believe it is capable of providing 600 Ohm audio with a 2175 Hz Status Tone required by the S-TAC or Digitac comparators. I'm not aware of this Subscriber unit being able to do APCO P25 Type 1 Astro signaling let alone providing the proper RS232 wireline interface to pass the Analog / Astro signaling as transparent down the wireline, enabling the Telco Link and allowing the either signal to becompared and voted.

Since you want a Voting system to increase your talk-in range from handheld Subscriber units, they'll need to make some concise decisions at your Public Safety Department. Neither of the oldest S-TAC or Digitac Comparators are capable of Astro P25 and not up gradeable to this format, they are only marketed as Analog.

The Astro-Tac Comparator is an Analog / Astro / Astro-Secure Digital comparator but it is not backwards compatible with the older Legacy comparators as far as signaling link formats. The ATAC comparator remaing in the Digital mode till a T5589A Astro-Tac receiver decodes an Analog signal. The receiver and comparator switch to Analog and is compared to other receive signal selecting the best and forwarding it on to the Quantar Base Station Repeater via a RS232 link out over the air and down to the Console. In the Astro mode the RS232 Links remain in the Digital mode passing Astro signaling to the ATAC comparator sampling all of the Digital bits for the best recovered signal and sent to the Quantar Base Station Repeater out over the air and the DIU converting Astro to Analog at the Console.

Although you had an interesting thought to manuver around the ATAC comparator ... I do not think this can be accomplished the way you envisioned the concept.

Now the decision is yours and in 8-9 years or less the FCC with APCO will force the Narrowband technology on the Public Safety Departments.

Dan

related topic.

what's the easiest way (read: least expensive) way to link astro systems via RF?

i need to link two quantar stations that are a few miles apart. leased line NOT an option ($$$$$$$$) microwave... see previous ... T-1's... HAHAHAHAHA

i need mixed mode too- analog in / analog out---- digital in / digital out

i do not need to support analog in / digital out in any fashion (no vocoding)



doug

Doug,

1) Are these individual Quantar stations required to have remote Consoles connected via wirelines?

2) Do they require bi-directional RF paths ... meaning if base station A transmits, base station B simultaneously transmits the same information? And when base station B transmits, base station A simultaneously transmits the same information?

3) Are both stations on Simplex?
Or
Full Duplex for repeat operation?

Dan

Hello,
I should have explained this a little better. THis is not for a public safety department, rather for a private repeater system. I understand that buying the right equipment would solve this problem, so keep in mind that this is a privately funded system, so buying a astro tac is a little out of the question at this time, unless one comes along cheap enough (but I havn't seen one yet)

There are a lot of people using the system with "analog subscriber units" a.k.a radios. There are a certain select few who have the use of astro. So with this also in mind having the abilty to vote astro vs. cost of equipment, we felt we didn' need to vote astro just analog.
so
this lead us to believe that a spectra tac would foot the bill. It is common practice to use maxtracs, gm300 etc for remote site radios and is easy to inject 2175 using a couple of different after mariket items. We also have a stock of spectra tac recievers/tx units that we could re crystal.

So at this point I guess that it would not be feasable. This is okay, we have some other ideas in mind which might be cheaper and easier to work.

As a side note, people keep mentioning a DIU, what is this device and what exactly does it do? Also, If we are lucky enough to obtain a astro tac if I read your post right there is no way to say have the "proper" astro remote reciever on one end tied through the phone line or microwave. What I am getting at is there problems sending the voted signal back to the repeater via conventional methods. Will astro signal go over a phone line to the repeater or over a micro link????

As a last note, while the quantro may be "obsolete" I would have to say that any one that was lucky enough to grab one for ham use, personal repeater etc is very lucky. It is a much better set up that the quantar from what I can tell. The MSF was a bullet proof radio, and combinding the best of both worlds to make a continous duty rig with a workhorse power amp and power supply was a great idea.

Thanks, Rob

Hello Rob,

Now having more information on the system configuration as being Analog Voting versus CAI, the S-TAC comparator can be incorporated into your private system with the older Quantro station. There should be some used S-TAC comparators available in the market place. I would suggest trying to get the comparators with the TRN6091 "C/D" version modules but the TRN6091B is acceptable. Some of the hybrid components are becoming Obsolete through AAD. A word to the wise, Do not mix and match the TRN6091 A, B & C/D version modules otherwise you'll be chasing your tail with compatibility issues. Remember you will need the TRN6095 Tone Keying module.

Since you have several Maxtracs and GM300 radio available, set two of them up as the remote satelitte receivers with the after market 2175 Hz Status Tone Encoders. For the RF Link perferability use another RF Band of operation, i.e. if you're VHF for repeating use UHF RF linking or vice versus proventing desense to your satelitte receivers. /\/\ made RF link Tx and Rx from 4 W HT90 series handhelds and combined with Yagi antennas it eliminated the need of Telco lines or Microwave equipment. Mobiles could be used in place but at reduced power output. For each satelitte receiver, you would need a separate transmitter and receiver besides the satelitte receiver/encoder.

Let me se if I can explain this in the simplest terms. At the remote site you would have a GM300 or Maxtracs satelitte receiver on the repeater's receive frequency feeding a GM300 or Maxtracs RF Tx Link. At the main repeater site you would have a GM300 or Maxtracs feeding into the T1786B S-TAC comparator second, third or fourth TRN6091 Signal Quality Module (SQM) input terminals. Each RF Link will require its own simplex frequency to avoid interference of the other RF links used in the system configuration. The first SQM Input is reserved for the colocated Quantro receiver/encoder fed directly into the S-TAC comparator.

You'll be required to modify the Quantro repeater's RSS in the station from repeater to a base station with "Fall BackIn Cabinet Repeat" in case the T1786B S-TAC Comparator should fail at any time. You'll also need to enable the S-TAC S.T. output on the second wireline and the station will need to be set up as a 4-Wireline configuration. Two wires for station receive audio to the S-TAC comparator and the other 2 wires for the Tone Keying with Tx Audio. Turn off the CAI parameter for P25.

Dan

I assumed you were doing an amateur type [low cost] project.

A DIU [Digital Interface Unit] is a magic box that contains an IMBE vocoder. It interfaces to the Quantar / Quantro with the Astro digital remote control format and on the other side it interfaces to analog contol consoles, phone patches, desk sets and so on. There is lots of information on the DIU in the archives here.

There is no reason you can't have a mixed mode single site P25, multi-site voted analog system as I previously described. The Quantro is programmed to believe it is a P25 repeater connected to a DIU which is connected to what it thinks is a console.

The analog voting system is completely independent. The voter keys the DIU as if it were a console, thus causing the Quantro to transmit the analog voted receive.

I have considered doing this for a ham repeater here. I want voting for county-wide portable coverage. I also want to experiment with P25. There will only be a few P25 users who will know that they have no voting coverage. The system will work but the larger issue is how the users will interact with it. Most hams won't understand about the P25 - it will just sound like noise to them. They will take you out of their scan lists and you will lose contact with most of your users.

Maybe that's OK for a small dedicated group.

Well as long as your analogue users are running PL/DPL decode, the P25 users won't even break squelch.

Hams? Running PL? ON RECEIVE?

On what planet would that be???

xmo wrote:Hams? Running PL? ON RECEIVE?

On what planet would that be???

I may not have the IMBE mojo that several of the guys have, but I at least run PL on the output from my TKR-750 hammy repeater. I don't even have to listen to the CWID.

We run PL on the outputs of a lot of the repeaters around here - even though they are CSQ on the input - just so folks can use PL on their mobile receive to keep out garbage if they drive through intermod alley, etc.

It's just that not too many can figure out how to! I don't really blame them - most of these new ham transceivers come with a book that weighs more than the radio!

Yeah, the PL seems to be buried 50 menus deep on a lot of them. Not as easy as just hitting the MPL button

I do the same thing you do on your TKR-750, tvsjr (I also own a 750, GREAT machine.) Is yours a -K2, factory ham split?

My MSF 5000 is programmed similarly, so I sit here with my radio in PL decode, and never hear anything except users. No CWID, no co-channel traffic, nothing.

I make it a POINT to put PL Decode on everything I can in the ham band, so I don't have to listen to all the co-channel traffic from adjacent cities, and the occasional intermod on the non-M radios.

If they don't want to run PL decode, it's their own fault. The feature is there for a reason. How hamsexy... CSQ radios!

d119 wrote:I do the same thing you do on your TKR-750, tvsjr (I also own a 750, GREAT machine.) Is yours a -K2, factory ham split?

My MSF 5000 is programmed similarly, so I sit here with my radio in PL decode, and never hear anything except users. No CWID, no co-channel traffic, nothing.

I make it a POINT to put PL Decode on everything I can in the ham band, so I don't have to listen to all the co-channel traffic from adjacent cities, and the occasional intermod on the non-M radios.

If they don't want to run PL decode, it's their own fault. The feature is there for a reason. How hamsexy... CSQ radios!

Actually, mine's a TKR-750K, because I've got it set up to serve as a backup repeater for a couple of our fire repeaters (change the channel and retune the duplexer), and since my machine is on 146.980. This box is actually a Version 2, which has the remote DTMF control, etc. I use the inbuilt controller and it Just Works. Even better that it's sub $1K.

I've got a standard Motorola ~5ft. rack with:
Kenwood TKR-750v2
Midland 150-watt power amp (it was free, and it's a damn good amp!)
GE ferroresonant 50-amp power supply
TxRx 6-can BpBr duplexer
Samlex smart battery charger
260Ah worth of high-rate discharge UPS batteries (good for 12 hours, 100% duty cycle)

And I've still got about 10U free.