Lectro UCR100 Reciever Troubles...
 

I recently purchased a set of Lectrosonic 100 series wireless mics. The first day they worked wonderfully. I coudn't get the reciever working today though. It has a brand new battery and I've tried it in various locations. One of the other camera operators thinks he "may have" turned the phantom power on the camera on. Would that short something out in the reciever?

All that it does now is turn on. The power light lights up, but it won't do anything else.

Please help...

I have only used a Lectrosonic once.

However, if the receiver was plugged into the camera via an xlr input and the phantom power was turned on, that would likely cause your problem.

I use a Lectro 200 series receiver. It's been plugged into jacks providing phantom power on a number of occaisions. It's easy to tell when you have because there is significant static when phantom is on. Does not seem to have any effect on the receiver once phantom is turned off.

I did a little looking around, and it seems that 200 and 400 series have circitry to protect against unnessary phantom power. Since I didn't see anything for the 100 series, I have to asume that it doesn't. I guess I'll find out tomorrow when the Lectro service dept. is open.

Thanks for your replies. I'll post what I discover, in case anyone is interested.

The 100 units have a circuit to block low-voltage "plug-in" power, but I'm not sure about full phantom power. It would also probably depend on how the adapter cable was wired.
I have had occasional trouble with my Lectro 100 receiver units recognizing when the transmitter was on. If the RF light won't come on even when the transmitter is a few feet away, verify their frequency settings. The units must be off for any change to take effect. Then cycle the on/off switches in a different sequence and see if the receiver will un-mute (RF LED on). Once they are working they keep working, but it can be a pain when setting them up. I don't take the transmitter to the remote location anymore without verifying everything is on and working. A friend of mine with two 100 sets hasn't had this problem yet, so it may just be mine, and possibly yours.

I spoke with the trouble shooters at lectro this morning and they said that the UCR100 receivers do include circitry to protect against phantom power. As for what's wrong they couldn't really guess without checking the units out. I'll have to wait to see what they say I guess.

I will say that these worked great when they were working. Hopefully it's not to difficult to get them back into that condition.

Thanks to everyone for there replies, and advice.

Dan Vellucci

I posted this stuff about the Lectro UCR 100 system a while ago, and just wanted to follow up on it for any future readers. The problem was apparently a "bad microprocessor". The bad news is that when I double checked if phantom power could have caused that problem the technician told me that it could have, but also that "it's electronics, and sometimes things just go..." This is a little annoying to me because, first he contradicted the earlier answer that the units were protected against that, and second because I like it more when problems have definite causes.

So, the phantom power question is still up in the air. If anyone does know for sure please drop me a line. Thank you.

Dear Dan,

If the unit has protection for when it is accidently plugged into phantom power, then this is a part of the circuit, and this part of the circuit could fail at any time.

If this part does fail, then you would never know that you did not have protection against phantom power until you plugged it in and it failed!

There may be a way to have intrinsic protection against phantom power, but I do not know how the circuit is designed. I do know that 48 volts is a lot of voltage to sensitive electronics that is not designed to accept this level.

Your problem may just be a fluke, but it does seem to be good practice to always have phantom power off unless you are using a phantom powered microphone and not some other electronic device.