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

I am wondering if I can use both 2 Wire 70V paging and 4 Wire 24 V Valcom

By sharing the same output

Customer wants to add additional paging horns to the outside of each building

I am a little concerned about possibly overloading TOA 724 Amplifier

So I was thinking of just using Valcom 24 v paging horns

Just for outside

any thoughts

Thanks



JD

What's your load on the 724 Amplifier? How many horns at what wattage do you want to add. Is that TOA a 240 Watt unit? If so, you may have a lot of unused power in there. Put an impedance meter on the circuit and go from there.

Sam

Hi Sam

Thanks for responding. Can you recommend and impedance media that I can buy?

I think they have a newer version digital versus Analog

Thanks

JD

This is a good impedance meter..https://dedicatedpresentation.com/toa-zm-104-a-impedance-bridge

But I am confused. Are you adding Valcom horns to the TOA amp, or standard 70V horns to the TOA Amp?

If you decide that you want to install 4-wire self-amplified speakers because you're worried that additional 70-volt speakers would overload the existing amplifier, you're going to need an adapter to tap off of the 70-volt speaker line and convert to a suitable impedance to feed the input of the 4-wire self-amplified speakers.

Something like V-1095 70V Paging Expander
https://www.valcom.com/products/productdetail/v-1095

Ok

So I guess I’m gonna measure the impedance and see if there’s any more room

I thought I could just double tap the audio output from Algo 8301 and send one into the amplifier for the 70 V system and then one into the Valcom for the 24 V system

I want to add three additional Paging horns to each building I believe each building currently has (1) Bogen 15w horns on out front

Bogen 15w tapped at 7.5

I still am not sure what you're trying to do, but let us know what your impedance readings are and we can take it from there.

I'm thinking that if you split the output from the telephone system before the amp that it shouldn't be a problem.

The Algo should be able to do just what you want. You may need to have 2 Algo units unless you can separate the output on the 8301

Ok

So I went out to the site with my new impedance meter TOA -ZM -104
I disconnected the speaker leads from the amp, connected it to the meter
I never heard tone coming through any of the speakers

The meter immediately went to zero ohms at 10X

Then it went to 10 Ohms I believe I was at 1X

I’m not 100 % sure on how to calculate

But I think I might be using about 200 Watts

Why, no tone I thought this was so you could tell if any of the speakers were disconnected or causing an issue



Thanks

JD

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

Work in progress

Ok

I have been working on installing external Valcom paging speakers to the outside of each building

This is a small charter school and every morning they play a song that lasts approximately four minutes to motivate the kids

They’re telling me that outside Valcom Paging Speakers, cut out intermittently during certain portions of the song

I have the output from the Algo 8301 double tapped going into the existing TOA 70v
And the audio pair from the Valcom

I’m going out there today to do some testing

Thanks

JD

Have you overloaded the Valcom power supply? What kind of cable did you run, and how far from the power supply are the speakers?

So I have an update on what I’ve done so far

After basically double tapping the output from the Algo, 8301 using the AUX OUT

Sending one pair of wires to the TOA amplifier (input 7) and the other pair of wires is going to the Valcom audio pair

The paging sounded fine. However, when they played music through it, it was all cut up on the outside speakers.

So I spoke with Valcom and they recommend using the 70 V adapter and tapping off the output of the amplifiers (speaker wire)

That seem to make a big difference

However, they are complaining that in one of the buildings cuts out only when the late bell ring

I talked to Valcom and he recommended instead instead of using the AUX OUT on the Algo 8301 to use the LINE OUT and connected to input one on the amplifier

I’m gonna be heading over there today to see what I can

Some of the bells work fine it’s just that one particular late bell. I guess they call it.

Does anybody have any information on the Algo 8301

From what Valcom was saying that the line out needs to be set for 600 ohms and then going into input one on the TOA amplifier.

Valcom is right- use the LINE OUT connection on the ALGO. Also, set the output impedance to whatever the TOA is looking for- probably 0db 600 ohms, but it may vary depending on the input module you're using.. Also, set the LINE OUT volume a little higher than the default setting of 4. Try 7

You can download the manual for the ALGO from their website. algosolutions.com

Ok

So I think we have the External paging horns corrected

Now back to the original problem

There are 50 ceiling speakers in one of the buildings (3) Flloors

Most are tapped at 2.5 or 5 watts I don’t believe they were tapped
This high prior to the Teams phone system & Algo 8103

The problem is the master volume is at 10 and input 1 is at 10
and is not loud enough in certain areas

From when I remember whenever I would install a speaker in the classroom, I would always put it at 1.25 and maybe maybe 2.5 if it was in a cafeteria or a hallway

I believe a lot of these settings got changed, because of the volume problem we initially had

I knew that the amplifier was getting maxed out, or possibly being maxed out. That’s why I introduced the Valcom speakers for the external paging outside.

I know that you should have more speakers at a lower wattage as opposed to one speaker at 5 W



I am going back this coming Friday to go through and see if we can find


Possible wiring issue that could be the reason behind this

I did put a impedance meter on it a while back and it was telling me that there was about 245 watts

Would this makes sense that because there’s too many speakers, and not enough wattage that you would have to turn the volume up to 10



My question is is what happens when you need more wattage

I guess I’m looking for some recommendations on possibly upgrading to a different amplifier with more wattage. I wasn’t sure if TOA made one.

I think Bogan makes one that’s 450 but I think it only has one input


Thanks

JD

Do a load test with existing 70v speaker runs before jumping on a new amp. If the load test is suspiciously high, or suspiciously low, check all the 70v speakers. Make sure nobody has hooked up a plain old 8 ohm speaker in a back room or custodians shop. That could cause most of the symptoms you're reporting.

Ok

I’m back on site. I used an impedance meter to get a couple of readings.
There’s two legs that come into where the speaker is connected to the amplifiers

The first leg is at about 180 which is the ground floor and the second leg is at about 30 which is the second and third floor

When I tied those legs together, it’s still measured the same as the leg on the second and third floor 30

The impedance meter is at 1X

I also just hooked up one 5W ceiling speaker at 1.25 Watts to the back of the amplifier

I was using my iPhone and input seven or eight I had the master volume up at halfway and I had input seven or eight up at halfway and I could barely hear anything coming out of the speaker

When I raise the master volume I think was almost all the way up and then input eight or seven I could increment those, and it would get louder

Does that sound like there could be something wrong with the amplifier

Years ago I was troubleshooting low volume on a car dealership paging system. I heard a page in the ceiling in an office in the service dept. - asked someone about it and he said they took a speaker from a car and wired it to the paging system - directly on the 70v line. It was actually a 4 ohm speaker. There was a big pillow wrapped around it to reduce the very loud level.

70.7V squared / 180 ohms = 27.769 watts
70.7V squared / 30 ohms = 166.613 watts

Together that's 194.382 watt load on your amplifier.

The two speaker lines together should have given you a reading of 25.713 ohms (70.7V squared divided by 194.382 watts)

I don't think your 250 watt amplifier is overloaded by these existing speakers.
And if a single 70 volt speaker tapped at 1.25 watts connected to the output of the amp doesn't give you good volume, sounds like the amp is tired.

TTT

Thanks for your response

What’s kind of strange is when I had both legs tied together I was getting the same reading as the one leg that had the 30 ohms

I definitely think there’s something wrong with the amp

I also noticed that the second and third floor are getting tied to the amp from a pair of wires from a voice feed
I should be able to correct this

The amplifier used to be at the other end of that voice feed. They moved it downstairs at some point.

Any recommendations on what amplifier I should be looking at?
I think TOA makes 250 W amplifier and that’s as high as it goes but I’m not sure

I’m assuming with the new amplifier providing everything looks OK those speakers can all get tapped down to 1.25 W and will be able to add more speakers because it seems like there is a few dead spots


Thanks

JD