Motorola Quantar UPCs

I have 2 Motorola Quantar at 110w each. I'm needing information on what type and/or recommendation on rackmounted UPC to use for each. We have a generator but it is not mounted at the site and the UPCs need to run about 20min minimum till someone can get upto the site and turn on the generator. However, we are setting the repeaters to be cut to half power when the power shuts down.

Why not utilize the battery backup feature in the quantar. Put 2 100Ah lead acid batteries on a rack mount shelf in a 24V configuration.

That is if you have the battery revert option.

Otherwise it really depends on the use of the repeater as how long it will run. Are they staying keyed the whole time?

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They won't be keyed all the time.. we do have the battery revert option but not enough space to allow batteries in the nema enclosure unless they are rackmounted.

In my opinion, I would rackmount some batteries if space allows. Then you could also reduce ouput power if you wanted and make them run even longer. You will need a 24v configuration so you could use 2 12v in series.

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They will be cut to half power if power is lost.. until we get on the hill to start the generator.

emtunderwood said:

They won't be keyed all the time.. we do have the battery revert option but not enough space to allow batteries in the nema enclosure unless they are rackmounted.

Click to expand...

We never put batteries in the same enclosure that the radio is in.

We do use AGM batteries that are rated for standby use.

If you want to go with with a UPS I would put a 1000 watt unit for each station.

I think the 100 W quantar will pull about 4 amps on 120V. It will pull around 10 amps on 24V.

So if you run it 3db reduced power it should run for around 30 min on the 1000 watt unit. That is calculating a continuous draw. I would always calculate for a longer response time given all the unknowns that could happen. So with a 50% duty cycle a 1000 watt unit could possibly sustain one repeater for 1 hr.

It you had the battery backup with a 24 v 100 ah then you could possibly sustain one repeater for 8.5hrs at full power or two for 4.25 hrs. Or both at 3db down foe 8.5 hrs. I think you get the picture.


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I never can remember if the last one I put battery backup on was 24V or 48V. I know the last one I put backup power on was 48V (used 4 12V AGM's wired in series, mounted at the base of an old Ma/Com cabinet) for I want to say a GTR8000 but I just don't remember if it was the GTR or Quantar. It's literally the only customer I have right now using a GTR (but like I said, wander around this site and you'll find Quantars, MASTR III and in an adjacent building even MASTR IIs).

Anyway, it would be more efficient to run batteries versus a UPS. Even you are using 4 6 A-hr batteries to do so (wont' run it long) per repeater.

How are you planning on cutting the power to half power using a UPC? Out of curiosity!

Also how are you going to be notified when you do loose power, so you can be in route with generator?

I know how I would do it, but then again I would use batteries for back up not UPC.

Is this a Ham Repeater?

Battery revert is the proper way to do it. My Quantars all have -48v battery backup to tide them over until the generator kicks in.

For a whole bunch of reasons, I am not a fan of the Quantar revert board, but it does have two advantages: (1) being Motorola recommended, it is a "safe" choice (remember the saying, "No one ever got fired for buying IBM"?); and (2) it is relatively inexpensive (particularly if you already have the board and your SCM is programmed to recognize it). Note that the 3 dB reduction in PA power is hard coded into the SCM upon LOOP (loss of offsite power).

I have implemented an alternative solution that works flawlessly, provided you (or your client) has the courage to think outside the Motorola box. It involves 2 8G31DT gel cell batteries, a device known as the "Heart Interface," and associated wiring, breakers, outlets.

The Heart Interface is a box that combines a battery charger, an inverter, and a transfer switch. Prior to LOOP, the HI passes 110VAC to the regular Quantar power supply. On LOOP (which is defined as RMS voltage < 90 or >135, or freq <56 or >64), the HI switches to inverter mode in less than about 18 ms, which is so fast that the Quantar does not see loss of power and does not reboot. (Nor, for that matter, does a Windows PC reboot.)

Our 2x8G31DT solution was designed to carry the Quantar for not less than 2 hours, using twice the typical 90-5-5 duty cycle (on the theory that if the lighst have gone out, the phones will be ringing). The only time we actually tried to see how long it would carry the Quantar before reaching the 50% discharge state, we quit after about four or five hours because we got bored and ran out of time. Note that, since the Quantar continued to see 110VAC at all times, there was no reduction in output power.

One of the upsides of this solution is that, unlike the Motorola revert board, the HI will not kill the batteries by trickling fully charged batteries to death -- a demise that is only recognized once the lights have gone out. The charger function of the HI is a sophisticated three stage charger that can actually go to zero charge on a fully charged battery bank.

The downside of my solution is that you have to be willing to bet your reputation on it working, you have to take the time to understand how it works and how to assemble the components, and if you purchase the components at retail, it will cost more than the revert board.

Battery Backup for 24v Quantar

Looking to add a battery backup to a 24v Quantar system.. Unsure on weather to use 4 6v AGM deepcycle batteries or 2 12v AGM deepcycle batteries. I have external chargers that will do a float and trickle which we used years ago on our older site but everything there was 12v DC not 24. I know the repeater shouldn't pull more than 4amps AC/DC. However, on the battery backup the drain should be around 450w when keyed and 60w just receiving. Just looking at doing this right the first time and getting the most runtime as I can, as in getting a generator to the site may not be practical.. As in we do not own the site.

Thanks.

Entirely depends on the capacity of the batteries. Typically you'd use two deep cycle 12V batteries in series but if you look around at the telecom 48V packs you'll typically find 4 12V deep cycle batteries in series on one shelf, then multiple shelves tied together in parallel.

Either way you go, there will be batteries involved.

So I vote for using the Quantar battery revert option, and program the Quantar for Alarm over air and wireline (if used) and power cut back.



It would be much cheaper than UPS's for sure, and less troublesome.