EEVblog #571 - Sennheiser G3 Wireless - Modding the antenna.. EE opinion wanted

[dhanson]

Great teardown on the Sennheiser G3!!

Wanted to bring up the topic of modding these by removing the stock whip antenna and retrofitting with a 50-Ohm SMA coaxial bulkhead connector. This would allow you to use a better antenna like a dipole or high gain antenna like an LPDA paddle antenna.

Some folks have done it and claim that it works well: (see the following)
http://jwsoundgroup.net/index.php?/topic/19338-external-antenna-for-sennheiser-g2/&page=3#comment-313661

My question: are there any electrical implications of this that are not being considered? Altering the impedance or introducing RF signal attenuation or something? Altering the ground plane of the stock design, etc?

I'm not an EE, just a location sound recordist, and I'm not sure who can answer these questions. Something tells me Sennheiser won't want to weigh in!

Thanks!
Derek

[The Soulman]

Not a real EE neither but a live sound engineer and frequent sennheiser EW G3 user.
Have experimented with different receiver antenna setups and came with different recipes for different situations, all with standard
sennheiser stuff.
Never did feel the need to mess with the SK transmitter antenna's as the system, when properly set up, functions flawlessly.
The reception on the small camera mount receiver (EK?) is pretty poor with its one antenna thingy, bear in mind it's designed for long battery life and small distance use (reporters etc.).
What equipment are you using and under what circumstances?

[sisal]

I'm at home in both worlds, and the requirements for the gear differ substantially.

On a stage for live sound you would have wireless mics and individual in-ear monitoring for each band member. With 4 mics, 6 in-ears, you are quickly up to 7-8 rack space units with receivers, transmitters and antenna distributors/concentrators. You would typically deploy an LPDA and a helical antenna for the vocals (because you know, vocals don't pay attention to polarization), and either another LPDA, a basic dipole or another helix for the in-ears.

In location sound, your 8 rack units need to fit in a little bag that you carry along the whole day. Thats where you shrink it down to have 1 transmitter that feeds boom-op, camera, AD etc. Thats where use those little receivers, and having external antennas (or at least proper whips for that matter) is a big plus - eventually that's why the more expensive receivers in this form factor all come with SMA plugs and not built in whips.

[dhanson]

Yup, exactly.