Help IDing this Celwave Part 639080

[alabamarailfan]

Hey Folks,
Hoping someone might be able to identify this part I picked up off eBay. The seller figured it was a pre-amp since it looks like a lot of Celwave pre-amps (albeit, a little smaller) but when I got it in and started looking at it, I am not sure. I don't have access to RF equipment to test it with (other than radios and SWR meters).

Here is the info printed on the label (visible in the photos as well):

CELWAVE
MODEL 639080 REV 8
FREQ 406 - 512 MHZ 806 - 920 M

Since there was no input/output only J1 and J2, this made me leery that it wasn't actually a pre-amp. The box is sealed (unlike Celwave pre-amps I have used before), so there is no popping it open to see what kind of guts are in it.

About all I can find on the Internet it that is could be used in a Celwave Multicoupler shelf. I found a model for sale of TDF6491A but still can't find out exactly what part this unit plays in the multi-coupler. Seems too small to be a pre-selector/filter and why would it have power. I applied 12VDC and there was no clicking or anything so I don't think it is a relay.

Thank you in advance for any input!
john

 

[kf8yk]

I'm pretty sure that's the bias T that injects DC up the coax to power a tower top amplifier, the multicoupler shelf normally includes an amp meter to monitor the TTA current supplied by this device.

 

[alabamarailfan]

Thanks for the input, kf8yk! I was wondering about a power injector as well. I just applied power and verified that power is output on the J1 port so that pretty much solves it!

Thanks again for the help and input! 73!
john