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Posted: Fri Apr 04, 2008 4:59 pm
by russellhltn
rknelson wrote:I know how to receive phone audio using the crab-box to bridge between the phone line and sound system. I don’t know a simple way to send the audio over a phone line other than the obvious – using a muted speaker phone. Does anyone have a simple approach for an “off the shelf” or easy to build way to take a line level or mic level signal and “insert” that signal into a phone?
The EJ-10 crab box has a mini phone jack on the side for anything you want played into the phone line. Since the EJ-8 doesn't have telephone capability, that's probably what you have.
Posted: Fri Apr 04, 2008 5:47 pm
by eyoungberg-p40
RussellHltn wrote:The EJ-10 crab box has a mini phone jack on the side for anything you want played into the phone line. Since the EJ-8 doesn't have telephone capability, that's probably what you have.
I believe the EJ-10 is only one-way: phone line to audio system. I don't think you can go the other way.
We used a true telephone hybrid. See:
http://www.bswusa.com/proditem.asp?item=TT1 Great audio, powered off the phone line. If you want to go cheap, bug one of the hams in your stake who's got one to use their hybrid phone patch. It's a bit of a messy setup, but it works.
Eric
Posted: Fri Apr 04, 2008 5:53 pm
by eyoungberg-p40
rknelson wrote:We are preparing for a stake conference "simulcast" to a second building in 3 weeks. This is our first attempt. I've really appreciated all the posts here and we have used many of the ideas over the past 3 months as we have implemented this. We are using a Slingbox to stream the video.
From the suggestions of others on this forum, we want to have an audio backup ready over a regular phone line -- just in case the video streaming runs into problems. I know how to receive phone audio using the crab-box to bridge between the phone line and sound system. I don’t know a simple way to send the audio over a phone line other than the obvious – using a muted speaker phone. Does anyone have a simple approach for an “off the shelf” or easy to build way to take a line level or mic level signal and “insert” that signal into a phone?
(Don't know if you saw this or not, but here is my second try at replying ...)
I believe the EJ-10 is only one-way: phone line to audio system. I don't think you can go the other way.
We used a true telephone hybrid. See:
http://www.bswusa.com/proditem.asp?item=TT1Great audio, powered off the phone line. If you want to go cheap, bug one of the hams in your stake who's got one to use their hybrid phone patch. It's a bit of a messy setup, but it works.
Eric
Posted: Fri Apr 04, 2008 7:35 pm
by russellhltn
eyoungberg wrote:I believe the EJ-10 is only one-way: phone line to audio system. I don't think you can go the other way.
Not the jacks on the top of the unit, the one audio jack on the side.
[color="Blue"]EJ-10 Manual[/color]
Posted: Fri Apr 04, 2008 9:40 pm
by rmrichesjr
The alternative hardware solution for driving a phone line is the 1:1 600 ohm audio transformer from the local electronics store. Feed the input to the transformer from a mixer with adjustable gain and adjust the level until it is comparable to a normal phone conversation and without excessive noise or distortion.
TNX for the EJ-10 manual!
Posted: Mon Apr 07, 2008 11:11 am
by eyoungberg-p40
RussellHltn wrote:Not the jacks on the top of the unit, the one audio jack on the side.
EJ-10 Manual
TNX for the manual. Since there is no specific adjustment I guess you just live with whatever sidetone you get. I've only used them for telephone to mic, not the other way.
We didn't have one of these in the stake center, only at the chapels. The hybrid we picked fits nicely into the satellite rack and ends up being a simple, clean sounding, no-hassle easy-to-use solution.
For what it's worth ...
Posted: Mon Apr 07, 2008 11:32 am
by russellhltn
eyoungberg wrote:Since there is no specific adjustment I guess you just live with whatever sidetone you get.
Sidetone is only an issue if the telephone connection is two-way. I've used fancy broadcast grade interfaces in the past and found the sidetone too high for use in a PA system. So that could be an issue.
But you're right, it seems there is very limited flexibility when it comes to piping sound into the phone line.
Posted: Mon Apr 07, 2008 11:36 am
by russellhltn
rmrichesjr wrote:The alternative hardware solution for driving a phone line is the 1:1 600 ohm audio transformer from the local electronics store.
While that would probably work, there's a couple of things that someone needs to be aware of.
First, the DC line voltage will be shorted out by the transformer if it's placed directly across the line. On one side, that's good because it takes the phone "off hook". But the transformer must be able to handle this without burning up or saturating the core and distorting the sound.
The other problem is to make sure the phone is picked up before the transformer is connected. The ring voltage on a phone line is around 100 volts. That would do some very bad things to the sound system it's connected to.
Posted: Mon Apr 07, 2008 6:47 pm
by daddy-o-p40
Very exciting stuff. Thanks for posting this info.
Posted: Fri Jun 20, 2008 1:16 pm
by KGBurton
And you might have (as we do) a phone jack right next to the A/V distribution center in the library ... easy connection from the phone line to the audio distribution amp.