IFB UM400a Audio Fades Away

[Brians1684]

Seeing if anyone has had this issue with the Lectrosonics UM400a BLK 26 in IFB mode. The issue encountered is, after about 10 min of good strong audio sending to multiple R1a units on set. The audio just fades away, comes back and then fade away. Here are all the things tried and observed to solve the issue. When I send it back to Lectrosonics how should I describe it? So I don't get a message back "We can't find anything wrong." because it looks and acts fine at first, but it seems to take a few minutes for it to happen.

Thanks

 

Observations:

1. Still solid green power light on UM400a

2. Green modulation on audio lights on UM400a

3. 3 other identical setup bag rigs with own IFB UM400a on other frequencies (swapped with others for testing) same result with bad unit

4. Sound Devices 664 x1 out put is used on all bags (swapped with others for testing) same result

5. Ta3 -Ta5 cables (swapped with others for testing) same result

6. Uses 9v eliminator (swapped with others for testing) same result

7. IFB is five frequency blocks away from nearest other Lectros on set and changed multiple times to clear channels and checked with other bags IFB to not be intermod.

8. Power cycle unit for 30 sec. fixes issue for about 10 minutes

9. Running just one bag or all bags with IFBs and same result with bad unit

 

[Steve Foy]

It would appear to me that you have done very well to isolate and therefore prove the unit in question is faulty.

 

A trip to the Mothership with all the same information you posted here should do the trick.

 

Steve

[David Silberberg]

Bad antenna?

Sent from my iPhone using Tapatalk

[Todd Weaver]

Sounds like some funkyness with the transmitter. Just send it in to the good people at Lectrosonics and they should have it up and running within a week or two.

[LarryF]

Seeing if anyone has had this issue with the Lectrosonics UM400a BLK 26 in IFB mode. The issue encountered is, after about 10 min of good strong audio sending to multiple R1a units on set. The audio just fades away, comes back and then fade away. Here are all the things tried and observed to solve the issue. When I send it back to Lectrosonics how should I describe it? So I don't get a message back "We can't find anything wrong." because it looks and acts fine at first, but it seems to take a few minutes for it to happen.

Thanks

 

Observations:

1. Still solid green power light on UM400a

2. Green modulation on audio lights on UM400a

3. 3 other identical setup bag rigs with own IFB UM400a on other frequencies (swapped with others for testing) same result with bad unit

4. Sound Devices 664 x1 out put is used on all bags (swapped with others for testing) same result

5. Ta3 -Ta5 cables (swapped with others for testing) same result

6. Uses 9v eliminator (swapped with others for testing) same result

7. IFB is five frequency blocks away from nearest other Lectros on set and changed multiple times to clear channels and checked with other bags IFB to not be intermod.

8. Power cycle unit for 30 sec. fixes issue for about 10 minutes

9. Running just one bag or all bags with IFBs and same result with bad unit

Hi Brian,

You seem to have done a good job of testing the unit and describing the problem. Send in a copy of your results with the unit and the crew should have no problem. From what you've said, this isn't an intermittent problem; it just takes a while to develop. 

 

Years ago we received a battery powered wireless sound system from an auctioneer, with a rather terse description of the problem.  On a scrap of paper, in pencil was written "The motor is broken."

 

You are doing much better than that.

Best Regards,

Larry Fisher

Lectrosonics

[Todd Weaver]

Yeah.. The motors in the old quad boxes were notorious for not staying up to speed.