atcomsystems.ca/forum Forums Wiring - Telecom Carriers - Trunks & Services Security, Alarms and Paging 2 wire Bogen with 4 Wire Valcom

Did you zero/calibrate the meter before connecting to the speaker leads? To calculate power, divide 4900 by the impedance reading. If you measured 10 ohms, that 490 watts, which would explain why you may not hear the tone. You won't hear the tone if there is a shorted wire, a ground fault, an overload, or a combination of all of these, and other things...

Yes on Zero out each time


The Amplifier on site is a 240 watt

Paging works I am just trying to see how much room I have left


I have a Bogen AT6 speaker which has 8,16,32 watt

I used the meter to test

Set on 10X

8w-100 ohm
16w-50 ohm
32w-25 ohm


Something doesn’t seem right

Any thoughts?


JD

No this doesn't seem right, are you sure you're calibrating the meter correctly each and every-time you use it? You must calibrate it each time you change scales. When you measure the impedance of the speaker lines, you have them disconnected from the amplifier, correct?
In 10 years of working on paging systems, I can't say I ever used anything other than 1X...not sure why you're using the 10X mode...
Are you sure this is a 70V system? Where are the speaker terminals landed on the amplifier? Have you checked the system for ground faults? Just because paging works does not mean the amplifier is not overloaded.

To answer the original question, you could probably just feed the TOA amp and the Valcom paging adapter from the same Algo output, as the TOA amp has a high impedance input (provided of course it is connected and configured properly as a line level output). It really sounds like you are in over your head though. My suggestion is to use only 70V speakers and forget the Valcom. No sense in having two systems to accomplish the same thing...

My apologies for being offline so long. Medical issues got in the way.

Are you still having the problem? Have you gotten anywhere with the trouble shooting?

The formula is P=V(squared)/Z

P is the power of the Amp in Watts

V(sq) on a 70.7 Volt system is 70.7 x 70.7, or almost exactly 5000 (

Z is the Minimum impedance of the circuit

So with a 240Watt amp you should see:

240 = 5000/ 21

So you should be reading NO MORE THAN 20 or 21 ohms. If you're reading 0 then maybe you've got a dead short out there - or more likely a speaker hooked up without a transformer.

Try breaking one of the speaker runs in the middle and testing both ways. See what you can find.

Sam

OK I am back out in the field in a different building. I have a TOA. 240 amplifier.
I just did an impedance test and it registers 20 ohms at 1X

So that looks like it’s using 245 W

Also the master volume and the input 1 are cranked up to 10




I’m sure if there’s a few speakers here that are tap higher than normal

When they switched over from the NEC to the Hosted team’s phone system using the Algo, 8301
The volume was really low so I believe they might have went around and tapped up some of the speakers in certain areas. Not realizing that this is probably something they shouldn’t have done.

Also, the page used to come through the NEC phones now it does not come through the new phones

The only reason that I’m working on this project is because they received some grant money, and they wanted to add some external Paging horns to the outside of the building

I think they currently have one Paging horn Bogen 15watt tapped that 7.5.

They want to add three additional Paging horns to each building, so my first thought was that could be a problem


I think I’m gonna try to hook up a Valcom Paging speaker and see how that works


Keep in mind this is a School so it can get loud in certain areas with the kids




Thanks


JD

Well you have your answer...the amplifier is overloaded. Now it's up to you to sell the customer on correcting the issues. Check the lines for ground faults and get the load under control. Then, you can add more speakers.

So this all started when they switched over to the Teams hosted phone system using Algo devices which is bizarre

You have to dial a 10 digit phone number wait to get answered listen for tone dial a code
1,2,3,4

It works about 50% of the time

I think there’s some sort of delay when you hang up before it disconnects from the master Algo

They allow anybody in the building to page

However, only one person could possibly page at a time

And on the old phone system, page came through the phone switch were in each classroom which made a big difference


I serviced their old phone system. I don’t service this one. The customer does.

They’ve already replaced all the phones because the original one sucked

You could only get to an extension number through the directory no dial pad 😳


(The NEC Aspire phones system was not an Issue)

1 Master
2 Slaves

I thought I saw a reply on a 1 watt amplifier to boost the volume of the Algo devices
prior to connecting to amplifier but I can’t find it

I believe most of the speakers were tapped higher by others not realizing

And the volume on amplifier is on 10 & the Input is also 10 it’s loud and has been working for a while now

The building I was in was one of the slaves

The ceiling speaker in the small classroom room I was in was on 5W

I changed it to 1.25 an it was too low

I know I have to dissect this an figure out what going on but I believe the Algo out put is too low
Not sure if a WMT1 would help

Any thoughts?

Thanks



JD

I'll explain further on my original post....

Why not split the output before it goes into the amp & use self amplified speakers for the new ones? I did it here on a Valcom paging system with multiple 30 watt speakers in the shop for a client and it worked no problem...

You are trying to treat a symptom, and not the problem. The amplifier is overloaded, as you have verified. There may or not be ground faults on the speaker lines. You should focus on resolving the problem, and not just treating the symptom. The volume of the system will come up when you resolve the issues with the 70V lines.

I installed (2) Valcoms external paging horns they work fine I will be installing more