PA System

[WSHI752]

Just curious, but why don't GMRS mobile units have a PA option like some CB radios do?

[WRTC928]

5 hours ago, WSHI752 said:

Just curious, but why don't GMRS mobile units have a PA option like some CB radios do?

I can't imagine it being very useful. I don't think even most CBs include it anymore.

[nokones]

6 hours ago, WSHI752 said:

Just curious, but why don't GMRS mobile units have a PA option like some CB radios do?

Why would you need a PA for? In most communities it is illegal to use a PA in a vehicle if you are not Public Safety.

[SteveShannon]

1 hour ago, nokones said:

Why would you need a PA for? In most communities it is illegal to use a PA in a vehicle if you are not Public Safety.

For our rocket launches I am the LCO (launch control officer) who announces the launch, counts down, and then presses the launch button.  The LCO is required to be able to command the attention of the spectators.  I’m also the guy who has his mobile GMRS station setup there with a battery so I can talk to the the rocketeers who have walked out on the range to recover their previously launched rockets.  
It would be great if I could use the GMRS station as a PA.

[GreggInFL]

42 minutes ago, SteveShannon said:

For our rocket launches I am the LCO (launch control officer) who announces the launch, counts down, and then presses the launch button.  The LCO is required to be able to command the attention of the spectators.  I’m also the guy who has his mobile GMRS station setup there with a battery so I can talk to the the rocketeers who have walked out on the range to recover their previously launched rockets.  
It would be great if I could use the GMRS station as a PA.

Don't many mobile radios have an audio out port for an external speaker?

[amaff]

9 minutes ago, GreggInFL said:

Don't many mobile radios have an audio out port for an external speaker?

yeah but that's a pretty different function than a PA, where you're talking into the mic and the same unit is outputting the audio, but louder.

[SteveShannon]

8 minutes ago, GreggInFL said:

Don't many mobile radios have an audio out port for an external speaker?

They nearly all do for reception, but they don’t allow you to send your own amplified voice to the speaker. 

[amaff]

2 hours ago, nokones said:

Why would you need a PA for? In most communities it is illegal to use a PA in a vehicle if you are not Public Safety.

What would you need a Jeep for? In most communities it is illegal to drive off the pavement.

 

See how that reads?

[WRUE951]

I remember that PA in my old PACE radio...   Almost had as much fun plying the PA then on the CB

[GreggInFL]

5 minutes ago, SteveShannon said:

They nearly all do for reception, but they don’t allow you to send your own amplified voice to the speaker. 

Okay, good point. My DB25-G has a jack for a headset. Perhaps some bubble gum and bailing wire could somehow make that work.

[nokones]

2 hours ago, SteveShannon said:

For our rocket launches I am the LCO (launch control officer) who announces the launch, counts down, and then presses the launch button.  The LCO is required to be able to command the attention of the spectators.  I’m also the guy who has his mobile GMRS station setup there with a battery so I can talk to the the rocketeers who have walked out on the range to recover their previously launched rockets.  
It would be great if I could use the GMRS station as a PA.

That shouldn't be a problem. There are all sorts of ways to do that. Take a GMRS mobile, tap into the audio out port, run the audio through an amp onto a speaker horn. Simple basic manipulation of electrons that an engineer should be able to easily make happen.

Let know how that turns out.

[SteveShannon]

43 minutes ago, nokones said:

That shouldn't be a problem. There are all sorts of ways to do that. Take a GMRS mobile, tap into the audio out port, run the audio through an amp onto a speaker horn. Simple basic manipulation of electrons that an engineer should be able to easily make happen.

Let know how that turns out.

Thanks, but apparently I didn’t explain my situation well. We are not trying to amplify the receiver audio. We already have a separate PA. I’d like to reduce the number of devices. Having a PA built into a mobile radio, like the old CB radios all seemed to have, would meet my needs well.

[nokones]

9 hours ago, SteveShannon said:

Thanks, but apparently I didn’t explain my situation well. We are not trying to amplify the receiver audio. We already have a separate PA. I’d like to reduce the number of devices. Having a PA built into a mobile radio, like the old CB radios all seemed to have, would meet my needs well.

Oh, ok, even my new (2 Years Old now) Cobra 29 LTD Classic AM/FM CB radios have the PA switch and jack port in the back of the radio.

[WSHI752]

Sorry, I totally forgot I posted this question last night, I was a little drunk.

But, my thinking was that it might be very useful to some people who use their radios for work, or off-roading, or what not. I think especially for like farm work or something like that. 

I just remember that back in the day a lot CB radios had that, and think it would be a nice feature to have. Not sure I personally would ever really need to use it (maybe when I do search and rescue it could come in handy).

[WRKC935]

OH,, PA's are FUN.

Driving past the football team and yelling out " RUN FOREST RUN" in a really goofy way.

Rolling up on a deer in the road and barking at it.  They fall on their ass while pooping all over the place.

"Driver, put down the phone and drive your vehicle" in some sort of official sounding voice can get the phone tossed in the back seat, hands at 10 and 2 and the guy or gal looking around for the cop car.

I skipped the CB PA setup and went right to the 100 watt siren for a cop car / fire truck.  The air horn function also works very well to get peoples attention.  Siren function was disabled, but the radio pass through was also handy for sort of what the OP was talking about.

Far as his situation.  The 4 watt amplifier in a CB radio driving a single speaker isn't going to put out much audio over a wide area.

Find a few tripods, get some horn speakers attached to those tripods and find a 70 volt professional audio amp to drive them.  Speaker horns should be 70 volt as well.

Then plug a mike into it and run some wires.  That would be your best bet.  A single point PA speaker to cover a wide area doesn't work for two reasons. 

First is that the level of sound in close would be too high if you wanted it to carry very far.

Second is tied to the first, you don't have control over the surrounding noise, so it would need to be really loud to overcome the baseline noise.   Spread out speakers that are not crazy loud will get you heard without scaring the deaf and dead.