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Re: Webcasting Voice Backup

Posted: Wed Aug 28, 2013 8:49 pm
by russellhltn
rmrichesjr wrote:IIRC, standard telephone levels are +8 or +12dB above 1mW into 600 ohms. That would be on the order of 2-3 volts of signal. That's considerably higher than most consumer-grade line-level outputs.

Correct. That's about right for pro-grade (XLR) type line outs, but only when running close to 0dB on the VU meter. Add any attenuation, (and the EJ-10 had quite a bit) and it goes down hill from there.

I 'd agree it probably needs something more then just line-out. It needs it's own amp. If you don't mind sparing it, a headphone out would work, but I think I'd be inclined to try and find a small speaker amp for it.

Re: Webcasting Voice Backup

Posted: Thu Aug 29, 2013 6:39 am
by jeromer7
Good discussion. Since the fireside webcast is tonight and I have other work that needs attention today, I am dropping the EJ-R for now and will use a speakerphone dialed in to the audio backup teleconference.

Last night I met with someone who was an audio engineer in a former life. He used headphones and touching the plugs just right was able to hear the audio on the tip of the stereo phone plug coming out of the mixer. But once plugged into the EJ-R we get nothing out on the phone line. We used Main Out as well as the Headphone Out jacks on the mixer.

A weird fact that I mentioned in an earlier post is that the handset mic is off when hooked to the EJ-R. It didn't matter whether the switch on top was in the "Off" or "Mute" position.

Re: Webcasting Voice Backup

Posted: Thu Aug 29, 2013 10:44 am
by russellhltn
jeromer7 wrote:A weird fact that I mentioned in an earlier post is that the handset mic is off when hooked to the EJ-R. It didn't matter whether the switch on top was in the "Off" or "Mute" position.

Ugh. You may be looking at a non-standard handset wiring. If the unit can't mute/unmute, then odds are it doesn't know the right wire pair to inject the audio on. All I can suggest in that case is try another phone or skip the EJ-R and find something else to feed the phone line.

Another thing to consider if the cable being used to connect. Some cables "flip" the signal, some don't. Depending on the wiring, a flip could render something unusable.

Re: Webcasting Voice Backup

Posted: Mon Mar 20, 2017 10:32 am
by msmith71
I realize this thread is now several years old. However, I am trying to get an audio-only backup solution working in our stake for our webcasts. In the process, I have learned quite a bit so I thought I would share it in case it helps somebody else.

First, there are apparently several editions of the EJ-10 box. Older EJ-10 boxes were designed to take a signal FROM a phone line, but they were NOT adequate to inject a line level signal TO a phone line. I spoke with a rep from Emtech who told me that the older EJ-10 versions had two transformers between the line level signal and the phone line that attenuated the signal too much to be useful.

The newer EJ-10 boxes have been redesigned and should be able to be used on either the sending or receiving sides.

He also mentioned that the Emtech EJ-R boxes were specifically designed to work on the sending side, and are about 1/4 the cost of the EJ-10.

We currently have an EJ-10, but I'm guessing it is one of the "older" versions because it has never been able to provide a strong enough signal for our audio backup solution.

I am requesting an EJ-R from our FM group and will give it a test to see if it works better. I will report back and let you know if #1) the FM group is willing to provide us with the EJ-R, and #2) if the EJ-R works better than the EJ-10 did.

Also, I will try to get more details about how to differentiate between different EJ-10 versions. This could be useful because some of you might already have a newer EJ-10 that will suffice for the sending or receiving sides, but some of you might have an EJ-10 that will only work on the receiving side, and it would be nice to know the difference.


Re: Webcasting Voice Backup

Posted: Wed Mar 22, 2017 9:05 am
by msmith71
Adding some additional information to my prior post:

It sounds like the EJ-10 boxes that are labeled as coming from the "IWE" company (Industry West Electronics) definitely will not suffice to send a signal over a phone line. Their design only supports receiving a signal. Also, for a period of time after Emtech procured IWE, the EJ-10 was sold with the same design but had an Emtech label on it. The tech support guy from Emtech that I spoke with today said that EJ-10 devices that were sold up until about 2014 or 2015 retained that older design, so they also would not be suitable for sending a signal over a phone line.

There should be an Emtech sticker on the back of the box (where all the cables are strapped on) that has a 4 digit date: MMYY. If the year is before 2015, I would be suspect of that box.

The tech support guy said that after 2015, the EJ-10 box design was changed and that it should suffice for sending over a phone line as well as receiving. He also said that the EJ-R box would provide an even stronger signal. I didn't ask him about that, but I thought it was an interesting statement.

The Help pages for Audio backup on ( ... s?lang=eng) specifically refer to using an EJ-R for the sending side and an EJ-10 on the receiving side. I have requested an EJ-R from our FM group, and once we have one, I will run some tests and let you know what we find.

I hope this helps!
Michael Smith