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Blue Box retraining

J

Jp

I use a Blue Box to do live, short weather broadcasts from my home on two stations. I do the broadcasts only on a fill-in basis and not every day. Sometimes several weeks can pass in between times that I do the broadcasts. I make a direct connection from the phone jack on a wall to the Blue Box, and there are no other “extraneous” items such as a fax or credit card machine, using the same phone line. My phone carrier is Verizon.

I used the Blue Box for over a year with no problems on either station. However in the past couple of months a problem has cropped up that I’m hoping someone can offer advice on solving.

On station “A” nothing has changed. I continue to make good connections on each dial in and the audio quality is good. However on station “B”, after having no problems for over a year, I have started to experience retraining. It doesn’t happen on every call in. I do one broadcast per hour over a four hour period, and consistently, the retraining happens at least once during the four broadcasts, sometimes more. The retraining does not happen at the same hour each day, nor does it happen at the same point while I am connected. Sometimes it happens several seconds after connecting with the studio and sometimes it can be two or three minutes into the connection before the retraining happens. When not cut off by the retraining, the audio quality to station “B” is good.

I should add that I do the broadcasts on both stations on the same mornings. The stations are located in two different states. I always get a connection rate of 24 KBPS. The engineer at station “B” had the phone company check their local dial line and said it was “clear and tests okay”.

Thanks in advance for any thoughts or suggestions on what may be causing the problem and/or how to resolve it.
 
Drop your connection rate to 19.2 or 16.8. It shouldn't have too much effect on your audio and the latency might improve ever so slightly.
 
Make sure that nobody's replaced the phone cord to the BlueBox with a cheapie. If the wires are able to move around in the sheath I’ve found that seems to cause a retran. One test is to slap the phone cord on the table top.

Had this happening on a 2-foot jumper in a studio. First tried replacing the connectors to no avail. Then made up a new on with different cable & the retran problems went away. Tested a drawer full of cords and found several that had the same issue.
 
If station "B" is using a phone line that has call waiting enabled, and someone else dials that number, the "call waiting" signal can cause the Comrex to renegotiate or just drop the connection.

Whether or not they have this feature enabled, you might try having station "B" call you instead of the other way around as a test. Sometimes that makes a difference in the world of POTS codecs.
 
Calling from the other end has saved us a few times.

Have had to "Flush Modem" several times on a Bluebox and a Matrix when they went weird with retrans.
Pages 28 - 30 in the manual http://www.comrex.com/assets/manuals/bluebox.pdf
Something gets corrupted in the modem's settings.

Also make sure the modem card hasn't become unplugged a little from the motherboard. Comrex has a mod to help prevent that that's on most of the later ones in the field.
 
Here are some things to check

Definitely check to see if the station has call waiting. To do this try calling from you cell pho0ne while the Box is connected. You should get a Busy Signal. If you get ringing you have found the problem.

Do you dial or do the stations dial you? Are both A and B local or both long distance, or one LD and one local

If A and B are dialing you, B may have changed carrriers.

In any case, try calling B in the opposite direction for a few days as a test. In otherwords, if they normally call you, try calling them. Or vice versa.

The fact A is OK means means your line is at least decent.

Set your maxrate to 21,800 (I can no longer remember the exact number but it is 1 or two steps down from 24 kbps. This as a general rul ethe fastest you want to run any modem if you want to avoid drops.

Other thing that might help is to try connecting directly to the network interface (you may need to broadcast for a different room or the basement for a few days to do so.

Also, if you location has the red-black-green-yellow wiring disconnect it from the network instrument and run a single run of twisted pair blue- white blue - orange - white orange - green - white green - brown - white brown cable.

Best of luck.
 
Yeah. I'd try reversing the boxes vs the phone lines at the station end. If the problem follows the box try what others have said. If not, it's s phone line issue. Telcos do develop issues with their circuits from time to time...
 
The blue box has the music mode. Set it to the other mode (talk?). It may be that one of the other end stations does not support the music mode fully.
Bill
[email protected]
 
It appears as though lowering the max connection rate may have done the trick.

I ran tests dropping the rate from 24.0 to 21.6 and then to 19.2, all in music mode. I then did the same thing in voice mode. At 19.2 the connection sounded very stable (i.e. no popping/crackling sounds) in both modes. Previously, at 24.0, retraining occurred within the four to five minutes that I was connected. I ran the tests at 19.2 for more than a half hour each with no problems.

Many thanks to everyone that offered suggestions. Much appreciated!
 
I had the same problem with my sports broadcasts. I would set the Blue box for a maximum of 24,000 when setting it up and after a minute or two it negotiated down one or two steps. If I set it NOT to negotiate it just hung up. We solved the problem by waiting until it established whatever rate it started with ( usually in the first 15 seconds after it fully connected with the other end) and then dropped it at least two maybe three rates down. The secret is to know the lowest rate it will stay up at so you don't negotiate down that low. The lowest I've seen is 10,500. It will run at 9800 but will eventually develope an echo. The voice setting is good as it will force the other end to operate at VOICE even if it is set at MUSIC. I understand Voice and MUSIC are different compressions and notm necessarly more stable one over the other.

The call waiting problem is spot on and will drop you out as will any intermittant line but if you get though ok to one station and not to another it would seem the lines not intermittent on your end. As I remember, the HOTLINE does not have a MUSIC stetting so if you dial into one at the station with yours set on MUSIC it may also cause a problem.

If you are diling in and leaving it connected you might want to set up the STL feature so you won't come back to it and frind it disconnected. The STL feature will reconnect to the other end if a failure occures providing the other end has a compatable box on it that autromaticly answers.

Good luck. I used one as an STL for years. I only found one number in the past five years that absolutely would notm connect.
 
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