Two Quantars & Standby or setup-knockdown

[FMROB]

Looking for some advice here.

I am going to have two quantar repeaters (not ordered yet) at two different locations (north & south) connected via microwave--4 wire wireline back to Hq's console. The south repeater will be the main operating repeater. The north repeater will be a "hot backup". I will need the dispatcher to be able to switch from one repeater to the other in case of a failure, preferably via wireline. Here are some questions and thoughts, looking for some insight to this.

1) Can this be a automatic switch, in other words in case of a failure of a pa, or loss of AC can I make the switch from south to north automaticaly.

2) I have given up all hope of the SAM module in these things. No matter what I do I can not get the blessed thing to do anyhting releated to the Quantar. (I am retarded). So in fear of furthering my stupidity with the SAM, is wireline an option?

3) Do I need a SAM to accomplish any of this, or just a TRC and Wildcard board?

4) Where can I find the programing instructions for any of these operatons Set up- Knock Down via wireline??

Thanks, Rob

[nmfire10]

Can you give a little more detail about how you are going to have these connected to the console? It sounds like you want two stand alone repeaters and the ability to switch the console and repeat to one or the other, and have the one that isn't active be totally dead? Yes?

[xmo]

Since you are planning on two Quantars tied to the dispatch location over 4-wire [microwave] circuits, I would recommend that you consider adding a voter to take fullest advantage of the second location.

Either way - with or without a voter - you can control which station is active as the transmit [& repeat] site from the console over the control circuits using TRC commands.

Unfortuately, since it is always a possiblilty that you could lose the control path to one or both locations, fall back in cabinet repeat is not a good idea.

Ultimately, it still comes down to the fact that over-the-air setup and knockdown capability would be essential. If the console location is disrupted or cannot control the repeaters due to failure of the console itself or of the microwave circuits, a backup control station could keep the users on the air. Alternatively, a comm leader or technician, equipped with a properly programmed mobile or portable could send the over-the-air commands to restore one of the locations to in cabinet repeat until the outage is corrected.

Despite your bad history with the Quantar SAM, this is still the right solution for over-the-air control. Its programming needs to be integrated with the Quantar's wildcard and TRC programming to create a total solution. A wildcard output should also be connected to the microwave 4-wire card to bring repeater status back to the dispatch console via E&M.

That status indication will allow the dispatcher to always know which repeater is currently active. If you program the station correctly, that single status output can reflect not only that the station is enabled for internal repeat, but you can map station faults and power condition is such a way that the status bit would go inactive for those situations as well. If you bring the status input to the console as an audible input, a change of repeater status or a fault could be immediately recognized.

You can conquer that SAM - if you start slow and work your way up. You really have to 'stage' the system at a suitable location where you have space and time to work. You need to have all the equipment in one place so you can send console commands to the station. You also need to have radios to test the over-the-air programming , have room for computers, manuals, notes, etc.

There is no way you can go out to a cramped repeater site, balance a laptop on your knee, spend five minutes to shoot something into the station, and be successful with Quantar SAM and wildcard programming.

Here is an example of a setup for programming, configuring, and testing a Quantar with SAM:



As you can see, there is a console position for testing the TRC commands, service monitors and radios for testing the operation over the air, a transmission test set for measuring line levels, and a computer for programming. The CEB racks are out of view to the right but easy to access for wireline and I/O connection testing.

I also tried to facilitate the project with the addition of an 'EASY' button, but that was not entirely successful.

[FMROB]

XMO,

You bring excellent insight into the situation. I was thinking of using a JPS voter and setting the quantars as base stations through the 4 wire e&m back to HQ's where it would vote and repeat (TX steer). I guess we could disable different sites from the voter or via the console into the voter.

Now, My arch nemises, The quantar/SAM/wildcard/TTRC

There is very little literautre about these radios. I have the SAM programing manual and the service manual for the quantar. I have spent hours trying to get over the air setup and knock down to work to no avail. I folowed the directions to a TEE inthe back of the manual. Nothing at all. I just don't understand the realtion and the tables and how all the cards and modules come together.. I wish that some could explain how it all works in one place or time, or maybe even send me a quantar & sam codeplug with working MDC over the air set-up and knock down so I can see what I am doing wrong. Maybe If I can see that I can work backwards to understand the relation of everything.


So if I were to use two quantars, a JPS voter, and SAM's I could have control over the wireline, repeater status to the console, and also have a field portable with DTMF that would do set-up/knockdown in case of wire line failure.

How would I handle both microwave systems going down simulatenously? In cabinet fallback repeat??

Thanks, Rob

[FMROB]

P.S.


Awesome shop. I have two of my own quantars with SAM's at my disposal, a service monitor, portables, and some tone equipment in the shop that I could set up befor I attempt this project. I have to master these things...

[nmfire10]

The JPS can easily handle your transmitter steering. There are momentary or latching inputs on the back to select what sites should TX. Aux outs from your console can drive these. You could use an tone panel to drive them as well. Lots of options.

The only thing you need the SAM to do is remote setup and knockdown of in-cabinet repeat. This would only be neccessary if you've lost both microwave links to both sites or lost the voter, either of which prevents the voter from doing the repeating.

[FMROB]

I would rather have the TX steering automatic. I would just want the console to be able to shut either of the sites down to force voting (repeating) off of one site.

The SAM and Quantar are still a mystery?? Hopefully XMO can help shed a bit more light.

-Rob

[nmfire10]

Your going to need manual transmitter selection to control the situation when/if one of the sites fails. If you have no manual control, it will be trying to site steer to a broken site. Even if you let it do automatic, you should still have the manual control for those bad days.

[xmo]

I understand the desire to have the main-standby operation be automatic. Dispatchers, or for that matter - anyone, have a difficult time remembering how something works if they only have to do it once every two years. So... let's see what some possibilities are.

The first thing that comes to mind is that the Quantar has a main-standby capability built in. Unfortunately, it is designed for the stations to be co-located. Several I/O's are cross connected between the stations. You might be able to reconfigure that arrangement to separate the stations if you had extra E&M capabilities between the sites, for example, other channels at the sites that are tone remote and not using the E&M on their time slots.

However, if you look at the factory main-standby - it creates something like thirtyone wildcard tables PLUS they warn you not to change them. It sounds pretty complicated to me. Sometimes complicated is necessary - but why do it the hard way if there is something easier?

A second concept would be to create wildcard programming in each station that uses just a single output as a sort-of "I AM OK" indication. In other words, drop that output on loss of power or any detected internal station fault. Then wire that back to the comparator site over the E&M and use the status of each station to control the comparator transmit steering, i.e A- OK, steer to A, A not OK steer to B, A&B not OK call for help!

There is a third concept to consider. Start with the console and comparator set up as if there is only one transmitter but route the transmit audio to both stations. The station designated as MAIN would be programmed normally. 1950 Hz F1 TRC from either the comparator or the console keys the transmitter. Simple.

The second site, the one designated STANDBY, can't key on the 1950 at the same time as the MAIN site [unless you want to do simulcast - which you could also consider]. What we need here is a way to know that the MAIN is FUBAR.

Why not simply add a monitor receiver that listens to the MAIN transmitter? Connect the monitor receiver COR to the Quantar as a wildcard input, then program the station so that every time it gets a PTT command it will first wait about 250 ms. and then check to see if the COR is present indicating that the MAIN is OK. If the COR is not active then the station would key up itself.

The advantage here is that this decision is automatic and evaluation is made on every transmission. The PTT of the STANDBY station should also be connected to the console via the E&M so that an alarm indication shows up if the STANDBY ever activates.

Manual override can be added with additional TRC programming or with I/O over E&M or at the comparator by disconnecting transmit audio from one of the stations.

Over-the-air conrol using SAM could be added to restore one of the stations if the comparator or console or channel bank goes down.