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Hooking a Blue Box to a prepriatory digital phone system

C

CaptBob92

My sports crew doesn't like to order telephone lines for high school sports broadcasts at gyms and stadiums. We now use cell phones but they sound like s..t. Most if not all of the phones that presently populate the bench or broadcast booth are part of the school's prepriatory phone system and are digital. If a Blue Box were to be plugged into one of these lines it would not work at best of would destroy the Blue Box at worst.

It appears to me that the handset on most of these systems is still analog. I'm wondering if I can place the Blue Box in the line between the handset and the phone and build something to fool it into believing it is seeing an analog line. I'm thinking of placing a hybred transformer in line with the phone to combine the four wire ( ear piece and microphone ) into a two wire connection which is what the Blue Box would see if connected to a POTS line. Further, I would float 25 volts DC on the Blue Box side of the hybred transformer to fool the Blue Box into believing it was seeing line current.

I'm wondering if passing the digital screech through a digital system will cause most phone systems to do strange things or will they just shrug and pass it though. Any old phone/radio engineers want to point out why it wouldn't work?
Thanks
 
No, it won't work. And you are correct in assessing that hooking up the Blue Box to a digital PBX system will blow the Blue Box up. You'll need a JK Audio THAT-2 to accomplish what you are wanting to do.
 
Most of the digital systems mess with the audio digitally to the point that it will drive the Bluebox, Tieline, whatever nuts. Does your bluebox system have IP options? Some schools have decent IP availablity. They all have connectivity, however, their firewalls can create hell if not configured to pass streaming, etc. If your box can do IP, consider this thought. Go get a cellular internet USB stick from two of your dominate local providers. Then get this: http://www.frys.com/product/5852383?site=sr:SEARCH:MAIN_RSLT_PG Pick the best one for the area. :)
 
Most schools are now using VoIP or other such systems. Depending on the type of speech coding that the system is using, they will probably not pass the data from the BlueBox correctly. We are lucky in that our home school still has us on an analog port off the PBX. However, we are having problems with the PBX blanking out the DTMF tones and then regenerating them to the PSTN, and the regenerated tones are too short for our Sine Systems dial-up remote control to catch. I can't lower the DTMF requirement on the Sine because then we will get a ton of false tone detections due to crowd noise. We don't have a codec right now (can't afford those on an LPFM budget).

On the road, we are usually resigned to using cell phones because generally a phone line is not available or costs too much money to be worth it for just doing one game.

You can see if some of the schools will work with you to run an analog port off their PBX. They sometimes can still do that to serve fax lines -- that is, if the fax lines don't run direct to the outside. You might see if you can get a split off their fax line -- most Athletic Directors aren't going to be sending faxes during a game because they are at the game supervising operations. The fax line may be direct to the PSTN (since they usually need a direct incoming # for the fax machine) and therefore the BlueBox might work.

Otherwise, you need to look into an IP codec and a 3G card. With ISDN and regular POTS lines getting harder to get, I think that's going to be the way of the future.
 
The local schools use VOIP and it does not play well with other digital voice gear.
 
Have had some really good luck with a Bluebox using the "modem" plug on the side of phones in hotel rooms. Those however seem to be disappearing.

It took a change in sponsorship of an arena to Qwest to get Bluebox usable POTS lines. Even when they had a special “fax/modem” POTS line installed on their digital system. Everything in/out of that building was and still is on fiber.
 
just had an install similar to the one you're describing. I located the Telco CO Block that feeds the digital system and wired an analog jack off that. Now, we plug into the jack (and unplug one telco line to the digital system).
 
I've found that at schools where analog phone lines are gone or have gone VOIP, there is now wi-fi or some kind of internet access. We just started using skype at some games. (Skype to Skype - no phone lines on either end) I didn't know until recently, but in the last version or so of Skype, they improved the audio quality. It is every bit as good as a comrex blue box in music mode. The delay is almost identical to that of a comrex codec.

I just made custom cables to interface between the line in and out of our comrex Vector to interface it with the audio in and out of a laptop. This way we can still use the vector as a mixer and headphone amp, but communication is via Skype on the laptop.

By the way, with Skype, the connections are all done by skype, so as long as you have internet access at both ends, it will work. You don't have to do anything with firewalls or port forwarding. Best of all, it's free!
 
Another option might be to use a PC equipped with a cellular system air card. Hook up a USB microphone to the PC and set up an account with UStream or a similar provider. On the studio side, just pull the stream in from UStream.

Later . . . .
 
Yup! Good idea on the Skype of uStream! I think Skype would have the best audio actually from my experiences. I actually did a live show (not on-air) with an audience and one guy coming in to the discussion via Skype. I only had a few hickups in three hours of show. It was great stuff!
 
I'm a little lucky in the fact that the home stadium we originate our HS games still has POTS and ISDN available. The schools IT department has a wifi connection but I don't need to use it.

On the road, everyone else this past season was in a new or recently remodeled stadium. POTS and Ethernet are available. ISDN is still available if we want (to pay for) it. Only one forced us to use a cell phone. They refused us access to a modem connection and claimed that an analogue connection was impossible from their VoIP system. We lated found out that the stadium manager at the school was in a turf war with the IT/Phone people. Phone lines were available but the stadium people refused to install them, or allow anyone to install them. Thankfully with the new district realignment we won't be back there anytime soon.

I'm going to add the JK THAT2 and their Bluetooth interfaces this year, just to be safe. We buy the time for our games, our originating station is well engineered and cooperates with our needs which is a big plus.
 
317C50KW said:
I'm a little lucky in the fact that the home stadium we originate our HS games still has POTS and ISDN available. The schools IT department has a wifi connection but I don't need to use it.

On the road, everyone else this past season was in a new or recently remodeled stadium. POTS and Ethernet are available. ISDN is still available if we want (to pay for) it. Only one forced us to use a cell phone. They refused us access to a modem connection and claimed that an analogue connection was impossible from their VoIP system. We lated found out that the stadium manager at the school was in a turf war with the IT/Phone people. Phone lines were available but the stadium people refused to install them, or allow anyone to install them. Thankfully with the new district realignment we won't be back there anytime soon.
Click to expand...
One thing that drives us to cell phone is the ridiculous fees that some of these sites charge. A $100 "hookup fee" to make one local phone call (or long distance via 800 number phone card) is ridiculous when I can use a cell and not put up with the hassle. Most of the time, the line is already active anyway.

Basketball season is our worst time of year for cell remotes since we can't get a Marti shot from inside a gym. Typically we can go on the Marti for most football and baseball games. I think I am going to experiment with Skype for our next football season, since most of the games we get that are outside of Marti range are at places that do have a Wi-Fi connection available.
 
One caution with Skype is that you are really really connection dependent. If you experience congestion somewhere down the line or at the access point (either Wifi and particularly 3g), you will get a lot of stuttering and sllllooooooooowwwww audio.

Skype is a great back-up plan.

We have a tiered system:

1. Comrex Access over wifi
2. Comrex Access over 3g
3. Skype over Wifi
4. Skype over 3G
5. Cell-phone (call into a softphone voip extension on a pc conencted to the control board)
 
DudeFan said:
One caution with Skype is that you are really really connection dependent. If you experience congestion somewhere down the line or at the access point (either Wifi and particularly 3g), you will get a lot of stuttering and sllllooooooooowwwww audio.

Skype is a great back-up plan.

We have a tiered system:

1. Comrex Access over wifi
2. Comrex Access over 3g
3. Skype over Wifi
4. Skype over 3G
5. Cell-phone (call into a softphone voip extension on a pc conencted to the control board)
Click to expand...

That's what makes me edgy about trusting my audio to the public Internet in general. For any remote we have a cell or POTS line dialed in to a Sine dial-up remote control, so if the IP transmission drops I can switch over to the phone feed quickly.

I would give anything to have a Comrex Access or similar device, but unfortunately the money isn't there at this time.
 
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