Adding Quantar to current system

[emtprt]

I have found a deal on a used UHF quantar for our system. Due to the voter location when a phone line fails we loose our repeater. Currently using 2 MTR2000 uhf repeaters and a few receivers through an Astro-tac voter. The plan- Quantar to primary site/ MTR to a receiver site every thing else stays as is. The quantar should operate as a free standing repeater during a line failure.

The back up dispatch center currently uses a 45watt mobile control station with a 6db gain antenna.

Question at this point will the Quantar integrate correctly with the Astro-tac voter and will it revert to a stnd alone device when phone lines fail

[Bill_G]

If the Quantar has a wireline card, it can be used with a voting system. The in-cabinet repeat during line failure is a function of the ptt priority programming. You give W (wireline) priority over L (local) and R (repeat). That is standard.

[emtprt]

thanks again for your help. I don't want to miss out on this deal.

[Batwings21]

Fall back in cabinet repeat is not that simple when you have multiple transmitters. What happens when you switch to the standby repeater? The main hears incoming traffic and gets no wireline ptt and boom two transmitters on the air at once.

[emtprt]

presently with 2 MTR200s 1 is primary and the other is the , which always acts a a reciever. Whe the AUX is selected the primary mtr200 is disabled and the second mtr200 becomes the active repeater.

If the Quantar replaces the primary MTR2000 and the MTR2000 it relaced were used as 2nd AUX or dispatcher selected base at the hospital could the sustem work throught the voter

[Bill_G]

Yes. It will all work together nicely provided the Quantar has a wireline card. You just need a method of preventing the Quantar from repeating when you use the auxiliary station. The simplest is to parallel both stations TX lines at the comparator, but put their RX lines on their individual rcvr module inputs. Use F1 tones to key the Quantar and F2 tones to key the MTR. Program the Quantar with a valid xmit freq in F1 and blank in F2. Program the MTR opposite - blank F1, valid F2. Now, only one station will transmit at a time.

So, what happens if you use the AUX station just before the phones lines go out? The Quantar will be on F2, and when it attempts to in cabinet repeat based on the PTT priority, there will be a blank xmit freq, and therefore no repeat. The solution is to program the wildcard with a simple script to change the freq back to F1 under certain conditions. I don't have the wildcard programming in front of me, but the concept will be IF PL DET, AND NO WL PTT, THEN WAIT 500MS, GOTO MODE 1, KEY FROM RCVR. It will take some experimentation if the person programming the Quantar is not familiar with the wildcard.

[MassFD]

Bill, that is a great idea for the wildcard programing but I have 2 questions

(1) does the base Quantar wireline module support wildcard or do you need the enhanced 8 wire card

(2) How would you get the voter to send F1 (main) or F2 (standby) control tones, I thought they always did a 1950 tone to key the station, at least that is what I remember from the SpectraTac days.

[Bill_G]

Those are great questions, and I have no answer. You have to work within the limits of the equipment the agency purchased, make the best of what you have, and Tom Edison what you don't. It makes the work a challenge for sure.

[xmo]

Assuming the station firmware is new enough, a Quantar with a 4-wire wireline card supports basic wildcard functionality.

With an 8-wire card the Quantar supports enhanced wildcard functionality which adds inputs, outputs, states & functions to the basic wildcard feature set.

The Quantar programming software manuals and/or help files contain a matrix which shows the wildcard features available for each wildcard type for each station configuration.

[emtprt]

I have a meeting next week at the comms center and plan to review all the phone lines and voter information that is presently in place. The receiver that would be replaced with the MTR2000 would need a phone line change. I would also plan on reassigning the receiver to a remote area that currently has margianl portable coverage during bad weather.

I was offered space on a public safety microwave system to replace phone lines but the cost is out our league.

[RKG]

There is another way to deal with the notion of a fall back in-cabinet repeat function in a voted system where you have two transmitters (a main and a standby), usually selected by a transmit steering relay controlled by a console Aux I/O--as someone previously noted, you can't use the Quantar's pre-programmed FBICR function. The rub of what I'm about to describe is that you need a SAM card in the machine that will do the fall back function. Here is what we have done:

1) Program the Quantar as "repeater" not "base."

2) In the channel screen, set Analog Repeater Access to "MDC/Tone." (This causes the Quantar to recognize the SAM and to require SAM qualification for repeat.)

3) Make a copy of the default SAM codeplug RAC.DEF and program the SAM with a set of over-the-air DTMF strings, one to turn on the function and the other to turn it off. The "on" code triggers Action Table 03, which puts the repeater in "setup" mode; the "off" code triggers Action Table 04, which puts it in "knocked down" mode.

4) Action Table 05 controls the status of the SAM on initial start up (or re-start after a power loss/restore). As set up by Motorola, the SAM initializes with the repeater in "knocked down" mode, which is what you want.

In normal operation, the Quantar's internal repeater controller is disabled (as a result of the machine being in "knocked down" mode), and the repeat function is handled by the comparator (which functions as an external repeater controller). When some drunk takes out the wireline, one of the dispatchers takes out a portable programmed with the DTMF strings, keys up, and sends the "In Cabinet On" string. The Quantar will now repeat via its internal controller (limited, of course, to its in-cabinet receiver). When the wireline is restored, use the same portable to disable in-cabinet repeat.

Two observations:

One: The foregoing may sound convoluted, but it works.

Two: while the SAM is a fine piece of equipment, it has two negatives: programming is abstruse in the extreme, and the SAM is very expensive. You can do the same thing with a $100 NHRS DTMF transponder and some wildcard programming of an unused input on the 25-pair connector. However, a lot of people hesitate to use non-standard hardware in a public safety system, which is why Motorola still sells very expensive SAMs.

[xmo]

"...the SAM is very expensive..."
___________________________

Given that the SAM option can decode MDC as well and also has its own wildcard I/O's - the 1K price isn't really outrageous.

With respect to Quantar wildcard and SAM options - I think we should enjoy these while we have them [less than a year left to order new Quantars].

I will be very surprised if Motorola puts this much field configuration capability into the GTR - at least not for some time to come.

[RKG]

[quote="xmo. . .

I will be very surprised if Motorola puts this much field configuration capability into the GTR - at least not for some time to come.[/quote]

I'd be inclined to agree, but I was a bit surprised to discover (quite by accident), that you can do the same thing (i.e., OTA DTMF control of setup/knockdown status) with the MTR2000 (using "Decoder 1" and "Decoder 2")--without any optional boards.

[Bill_G]

Oh, no kidding? (off to play ...)

[MSS-Dave]

Oh, no kidding? (off to play ...)

X 10 !!

[Bill_G]

I couldn't get it to work the way I wanted. The rptr activation and deactivation was not latching. It only lasted while carrier was present. I didn't have a choice for dtmf either. But, it did respond to single tone set to columns or rows correctly (half tone).

[RKG]

Well, I started to play with this the day I discovered it, but was then distracted into a different project, so I hope I didn't speak too soon. By appearances, however, is should be possible to duplicate the "setup"/"knockdown" function using the "decoders." As soon as I can free up some time, I'll give it a test drive.

[emtprt]

I was told that an MTR2000 could capable of reverting to a free standing repeater if the voter looses telephone service and that a control station will work inplace of the standard 4 pair to the repeater. I would assumue that any repeater primary or aux would revert causing overlap and a hum unless gps/multicast were in place.
Right now if a phone line goes down at the comms center our only dispatch capabilities are changing the channels on the controls stations to direct and tone encoding from a CDM1250. Then having the mobiles and portables sign on a secondary free standing channel. The control staions would be notifiled via phomne of the call and someone would need to respond to a firrehous and tone out the EMS or fire fire units.
I did program the pager tones into my mobile radio and ht1250 so I could attempt to tone out a call from my car(if the system failed).

I do have a meeting next week to move the voter and set up a control staion at the comms center to decrease phone lines and increase back up options.

[Bill_G]

Yes - Like the Quantar, an MTR is capable of in cabinet repeat upon phone line failure based on the PTT priority. If you define either of them as a repeater, rather than as a base station, and give wireline PTT priority over receiver, then a comparator will have control over them during normal operation. If the phone lines fail, both models will repeat. That is the danger Batwings21 pointed out. In a hypothetical system with multiple transmitter sites, if both models are programmed as repeaters, and one or more lose phone lines back to the comparator, then two or more stations will key up creating a mess. System planning has to include worst case scenarios that prevent that, and allow only one transmitter to be active at a time. How that is achieved is based on your total system capability.

Re-reading your original post in this thread, if the only reason you are purchasing the Quantar is to gain the in cabinet repeat functionality, then you should already have it in your existing MTRs. Someone needs to review the programming, define the primary MTR as a repeater, and set the PTT priority with W (wireline) first followed by L (local) and then R (repeat). Upon valid receiver input, the MTR will look to the wireline from the comparator first for a transmit command. If that is not present, it will look at the local system plug. If that isn't present, then it will internally repeat. Wireline will always have precedence over repeat. If at any time the phone lines fail, and are then restored, the station will faithfully continue to repeat with or without the benefit of the comparator, and without any intervention by dispatch. If dispatch only has a console connection through the comparator, then they will be off the air during a phone line failure, and need to revert to a backup station. How that all plays out depends on how your current system is knitted together.

In other words, you may have all the bit and pieces, but need to rearrange them to get the contingencies you want.