Paralleling DC voltages to/from wireless mic reciever. Should I worry?

hey guys, looking for some opinions on this:

Here's the deal:

Sennheiser EW 300 G3 receivers.
They can be DC fed via a "wall wart" PSU feeding DC into a dedicated jack on the back of the unit.
They can also receive their DC voltage via the BNC antenna connections, typically from an antenna signal distribution unit that also passes along DC to the various receivers.

It's not illogical to think that there is some sort of parallel connection of the DC voltage on the PSU jack and on the BNC connectors on the back of the receivers. A diode network could prevent the various jacks from "seeing" eachother.

Measuring DC on the BNC connector with a DC PSU connected to the DC input jack shows 4 volts "coming out" of the BNC out of the 12 volts being "put into" the DC jack.


I'm wanting to use these receivers with a passive antenna distribution unit that does NOT pass along DC via the BNC connections, meaning that I will have to feed the receivers via the dedicated DC input jack.

The distro unit is passive in terms of its RF operation, but it will need to be powered on anyways, as the antenna inputs on the front of the unit is to provide DC power to "active" antennas via those BNC connections.

Would you worry about this?

Please let me know if I was unclear.
 
Re: Paralleling DC voltages to/from wireless mic reciever. Should I worry?

The passive splitter/combiner should incorporate a DC block. The DC out from the BNC should incorporate a current limiting resistor to avoid smoking the power supply... but why risk damaging it?

The passive combiner most likely will result on poorer performance then using individual antennas.

If the passive combiner is a home made bunch of T connectors... good luck.
 
Re: Paralleling DC voltages to/from wireless mic reciever. Should I worry?

No. 12 vdc is 12vdc it's not like combining ac where the waveforms have to be in phase.

You can supply phantom on a direct split from 2 consoles and it's fine.

Sent from my XT907 2

Thanks Silas.

I realize this is the general perception and stuff like paralleling phantom power between consoles is OK.

I also have enough electronics knowledge to know that the world isn't always QUITE that simple. Since the BNC connectors only output 4 of the 12 volts the DC jack is being fed, one could imagine scenarios where the voltage differences between two sides of a diode could make it "open up" at an incorrect opportunity. Stuff like that.
 
Re: Paralleling DC voltages to/from wireless mic reciever. Should I worry?

The passive splitter/combiner should incorporate a DC block. The DC out from the BNC should incorporate a current limiting resistor to avoid smoking the power supply... but why risk damaging it?

The passive combiner most likely will result on poorer performance then using individual antennas.

If the passive combiner is a home made bunch of T connectors... good luck.

Hi Tim.

Thanks for your input!

It's an original Sennheiser unit called PSA2, not a home-brew bunch of crap...

It was not possible to power the older style of Sennheiser receivers from the BNCs, so the ASA2 distro unit does not output DC on the BNC jacks, it has four separate DC outputs meant to feed the receivers via the dedicated DC input jacks.

Since then then, the EW 300 G3 receivers have appeared, and they DO have the ability to be DC fed via the BNC jacks, meaning they will output a DC voltage on the BNC when being fed via the dedicated DC input jack, which is the scenario I will be using them in now.

Individual antennas becomes a mess when dealing with unidirectional paddles :lol:
 
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Re: Paralleling DC voltages to/from wireless mic reciever. Should I worry?

My show of the day: 4 ULXP's with distro. Paddle not used today. I think with the active antennas you will make up for the losses in the passive combiner therefore: don't worry, be happy.
 

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