outdoor radio mic antenna

[hutch@minack]

Hi all,

 

We run 8 Sennheiser G300 mics here at Minack and have used 1031 paddles but the salt air attacks them and they don't last a season. Anybody out there have a better outdoor solution?

 

 

Thanks, Simon

 

[Dave m]

What about simple PET zeppelin bottles (or similar?) to create a waterproof enclosure?

If you had the facilities you could vac form two halves or drape mould something by making a wooden former

[Simon Lewis]

- Use a waterproof coating? - perhaps bitumous type paint?

- Seal in a watertight cover? - such as a plaster cast protector

- Consider whether an alternative waterproof antenna might be suitable? I'm aware that there are (e.g.) waterproof GPS antenna for marine use but couldn't say if their wide bandwidth woudl be an issue for you....

[Chappie]

Maybe have a chat with someone like Radio Structures, who specialise in outdoor antennas and masts. They would be able to make you something custom, if you have any special requirements (bandwidth, cable length etc).

[bruce]

Ian Hickling at Transplan UK should be able to sort you out. He specialises in RF antennae and radio systems, and does a lot of work with community broadcasters throughout the UK - many of which use custom antennae systems. I spoke to him earlier, and he says to drop him a line. ian@transplanuk.com

[hutch@minack]

awesome thanks, will try Transplan and Radio Structures.

 

Ian Hickling at Transplan UK should be able to sort you out. He specialises in RF antennae and radio systems, and does a lot of work with community broadcasters throughout the UK - many of which use custom antennae systems. I spoke to him earlier, and he says to drop him a line. ian@transplanuk.com

 

Thanks for mentioning it to him, I've dropped him a line tonight.

[abbotsmike]

What fails? The antennas themselves or the connections? If just the connections, self amalgating tape may be your friend!

[chelgrian]

What fails? The antennas themselves or the connections? If just the connections, self amalgating tape may be your friend!

 

Having had experience with Simon's paddles (I always bring my own spares when visiting the Minack for exactly the reason Simon posted here) they look like:

 

https://assets.sennheiser.com/img/604/product_detail_x1_desktop_square_louped_a_1031_01_sq_accessory_sennheiser.png

 

You can see the BNC at the bottom but what you can't see is the rear of the paddle where is there is a potted wire attached the paddle underneath the paint which then goes in to the BNC. I think what fails is that the wire connection between the BNC and the paddle corrodes from the inside due to ingress of salt water into the BNC connector.

 

You could try potting the entire BNC connector but it's going to be faff when it does eventually go wrong and you have to cut it off and re-terminate the BNC cable. A custom antenna with a weather proof connector is likely to be better.

[J Pearce]

A lightweight plastic housing ought to provide sufficient protection without causing significant attenuation of the wireless signal.

[chelgrian]

A lightweight plastic housing ought to provide sufficient protection without causing significant attenuation of the wireless signal.

 

It would have to be hermetically sealed around the cable otherwise it will do nothing and in fact make matters worse due to salt water collecting inside the housing. You've got salt spray coming vertically up the cliff from the English channel.

[J Pearce]

Oh yes, I understand the issue at hand. A good gasket sealed box, with a proper seal round the cable and cable entry position chosen to avoid the worst, and the antenna up high in the box so any collecting salt water remains at the bottom out of the way ought to at least slow the corrosion compared to open air.

[p.k.roberts]

I have no experience of this stuff, it seems to be mostly aimed at the car market - creating a sealed, flexible peel-able coating. It looks like it might be worth a try though.

 

https://www.amazon.co.uk/Plasti-Dip-Mulit-Purpose-Rubber-Coating/dp/B0114Z42F8/ref=sr_1_8?hvadid=80676697946252&hvbmt=be&hvdev=c&hvqmt=e&keywords=plasti+dip&qid=1559229851&s=gateway&sr=8-8

[bruce]

A handful of thick grease would be quite effective... but a proper outdoor antenna, with self-amalg tape, and maybe some grease on top, would be my preference.

[abbotsmike]

Yeah in that case someone like lintec or radio structures should be able to make something suited to the need. Might even see a boost in performance, those sennheiser antennas are very convenient I know, but they're also very very wideband. If everything is in the same frequency range it's not the most efficient system.

[Jivemaster]

WHile a "tupperware" solution may be cost effective, there must be something from the marine market that is built to accept corrosives such as sea mist as normal.

 

A custom moulding in glass filled polyester resin will be radio transparent, carbon fibre absorbs and blocks RF.