Waterproof Radio Mic

[revbobuk]

This is a bizarre request. I've been asked by someone who does an aquarobics (is that how you spell it?) session if there is a waterproof version of the headset radio mic and beltpack setup that aerobics instructors use. Obviously it would either need to feed into the pool PA or some sort of battery powered poolside setup - but ignore that end for now. Are waterproof transmitters available? And is it possible to find a mic that could cope with the damp / high chlorine atmosphere?

[mackerr]

This is a bizarre request. I've been asked by someone who does an aquarobics (is that how you spell it?) session if there is a waterproof version of the headset radio mic and beltpack setup that aerobics instructors use. Obviously it would either need to feed into the pool PA or some sort of battery powered poolside setup - but ignore that end for now. Are waterproof transmitters available? And is it possible to find a mic that could cope with the damp / high chlorine atmosphere?

 

It is unlikely that there will be anything that will stand up to constant use under those conditions, but there is at least one water resistant transmitter, and the Countryman Isomax capsule has been demonstrated working while in a can of Coke.

 

Mac

[andy_s]

Do you need something that can withstand complete immersion? if so, I'd think looking for some kind of waterproof case like you can get for cameras might be worthwhile. A quick google found these from Ewa Marine (A German company) unless someone else knows of a specific waterproof radio TX. You would possibly need to make a hole in the bag to pass the mic cable through, and then reseal around the cable, so changing the mic head could be a bit of a pain ...

[dbuckley]

Adn just a note, just in case - the antenna needs to be out of water, as RF doesn't travel well through a swimming pool :** laughs out loud **:

[StevenW2]

I looked into this for our local leisure pool and came up with a product called the "Baqua-pack".

 

A small, neoprene rucksack to house the transmitter. It was rather expensive, so they didn't buy it in the end!

 

Didn't manage to find a waterproof mic capsule in their budget though.

[the kid]

I'm sure I have seen some of the guys at Covent Garden using a mic pack that is just head based, not sure who makes it though.

 

You could get a splash/waterproof one and and fit it in to a cap or some kind of head holder. Only thing is to make it waterproof.

 

What do other people do?

[cedd]

In my student days I worked as a lifeguard at the local leisure centre.

 

They had an aquarobics session pretty similair to this one. The tutor had a beltpack in one of these;

aqua pac

Seemed to behave pretty well. She looked to have a standard very big black plastic headset on (she also looked uncannily like Britney Spears, so it finished off the ensemble rather well), no idea if it was properly water proof or not.

 

She wore the beltpack on her upper back.

 

Of course swimming pools are known for their wonderful accoustics......

[revbobuk]

Brilliant. The Aquapac looks just the business - and a reasonable price too. Put that together with a sweat-resistant aerobics headset, and I'm home and **dry**! Thanks folks - you have been a great help.

[andy_s]

Adn just a note, just in case - the antenna needs to be out of water, as RF doesn't travel well through a swimming pool :** laughs out loud **:

 

drifting a bit off-topic (strong currents in this swimming pool :blink: ),

 

I wondered whether this might be an issue, but thought of watching TV programmes about underwater archeology where they appear to be in radio contact with the surface. Somethimes there is very clearly an umbilical in evidence, so I quess the audio is cable-borne, but sometimes they seem to be free-swimming with no physical link to the boat on the surface. Anyone shed any light on this? (perhaps they are miming to track or their words are dubbed in post-production !!!)

[cedd]

I think it's probably safer to say

as RF doesn't travel well through a swimming pool

....at most normal frequencies

 

Talk to a submarine commander about RF communications (at Very Low Frequency - 3 to 30 khz) and they'll tell you they can receive perfectly well through water (but only data - no voice). Unfortunately they also need a huge aerial for these frequencies, which is why they tend to receive only.

 

As frequency increases, so attenuation by water (especially sea water - salty!) increases. This doesn't mean it's not possible, but it ain't going to get very far!

I have a feeling that most underwater subs are on umbilical cables, whilst comms between divers is normally low range, so they're probably using a fair bit of power and as low-a frequency as possible.

I'd also guess they don't worry too much about licensing - I think the likelihood of such a signal leaving the water and making it to air at anything like a usable power is pretty low.

 

Purely for interest, this article is quite useful (opens a pdf document); Underwater communications

[ramdram]

(A bit OT but still to do with wet stuff) Beat me to it cedd! ELF works for miles and miles and miles, virtually all over the planet, but not very deep...the downside is the aerial...it is quite "long". I believe a length was once found wrapped around a fishing boat's prop...it had been disguised to look like seaweed:

 

ttp://en.wikipedia.org/wiki/Communication_with_submarines

[Paul TC]

Keeping off topic, these recollections from the 1970's re Police divers comms might also be of interest. 1970'S Underwater comms.

[JackBrienLX]

For water resistant mics you might want to look at the Da Cappo mic range, I believe Orbital are the only company that supply them at the moment (although I may be wrong!). Apparently they are very sweat resistant which should make them fairly water resistant also, the chlorine could be another issue however.

 

Also I am unsure whether the sweat resistance they claim only applies to the capsule, they also have a behind the ear connection which may not be so resilient.

 

Might be worth a look either way!

 

HTH

 

Jack

[revbobuk]

I now find that after all this research I know more about aquarobics than I ever wanted to. One supplier has been encouraging me to use VHF rather than UHF radios, because, he says, the Cardio fitness suite (usually in the same building) uses the channel 70 frequencies for transmitting to the treadmills and other gear. Anyone know of information available so I can check this? I'm sort of surprised it doesn't use 2.4GHz. After all, it's really short range. I presume he means the chest mounted pulse sensors and the like.

 

There appear to be a couple of mics that are almost standards - the 'Aeromic' and the Fitness Audio 'E-mic' which have some moisture protection. None of this stuff is cheap, though.

 

(actually - I think the 'Cardio' stuff may be for music feeds back to the punters - IEM use, in effect. In which case the channel 70 thing is probably true.)

[Simon Lewis]

(actually - I think the 'Cardio' stuff may be for music feeds back to the punters - IEM use, in effect. In which case the channel 70 thing is probably true.)

 

One poster had exactly this problem. Tried to use a UHF mic at several leisure centres, and couldn't get rid of the muzak broadcast from 4 frequencies in channel 70.