http://www.amazon.co.uk/proster-Walkie-Talkies-Range-Charger/dp/B00OK7XCOK  Thanks!

We have used Motorola ones for doing big shafts in the past. I think they do an extreme one which is weather proof.

http://www.onedirect.co.uk/motorola/motorola-tlkr-t80-extreme?gclid=CNWM5MD1vMkCFYXnGwodTBsP4w&LGWCODE=MOT80EXUK%3b55331%3b2389 

I would stay away from unknowns on this and use a good brand.

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Thanks for posting this Mike. Been considering something like this for an ongoing project with potential wet shaft dangling.

If it gets the Mr Mike seal of approval then I'm sure its worth every penny of its not-that-expensive-after-all price tag!

regards,

MARK

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Hi Mark - when we used the Motorola ones they where a basic set that I had borrowed, we had them inside our oversuits using the voice activated mode - did not have headsets. It was when we did the Frog Shaft through trip for the 1st time.

It is some time ago, but I am sure we managed to keep in contact over each leg of the shaft, prob biggest distance we ended up having comms was 50m, can't comment over that.

I've never used or seen the Extreme version, but it figures that they will be better.

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The wet shaft thingy is way off in the future, although there is a possibility of laddering the lower, dry section to the first inset.

I'm thinking also of comms along the horse level as we're now commencing a spoil tipping phase 100m outbye from the current dig, using a rope-haul rail bogie. We're in the process of installing a bell signalling system but Vox would also be real handy - there's not really a bell signal for "can you find me a 5ft length of telegraph pole and a couple of fishplates" ;D

Hope your back is on the mend :flowers:

MARK

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there's not really a bell signal for "can you find me a 5ft length of telegraph pole and a couple of fishplates" ;D

You could always try Morse Code!!! :lol::lol::lol::lol:

what? with my s-s-s-tutter?? :o

MARK

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The wet shaft thingy is way off in the future, although there is a possibility of laddering the lower, dry section to the first inset.

I'm thinking also of comms along the horse level as we're now commencing a spoil tipping phase 100m outbye from the current dig, using a rope-haul rail bogie. We're in the process of installing a bell signalling system but Vox would also be real handy - there's not really a bell signal for "can you find me a 5ft length of telegraph pole and a couple of fishplates" ;D

Hope your back is on the mend :flowers:

MARK

Mark there is always the option for the use of military field telephones ask ian s next time you see him

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Yes, field phones, might be better than WT's in a dig with mud and all that left right and center. WT's Ok in a relatively 'clean' shaft situation.

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I would stay away from unknowns on this and use a good brand.

Agree, the cheapo ones are a waste of money and are sometimes very unreliable.

Garden hose and two funnels?;D

The wet shaft thingy is way off in the future, although there is a possibility of laddering the lower, dry section to the first inset.

I'm thinking also of comms along the horse level as we're now commencing a spoil tipping phase 100m outbye from the current dig, using a rope-haul rail bogie. We're in the process of installing a bell signalling system but Vox would also be real handy - there's not really a bell signal for "can you find me a 5ft length of telegraph pole and a couple of fishplates" ;D

Hope your back is on the mend :flowers:

MARK

I'll bring a pair of PRM walkie talkies down. they are good getting on for 2 miles above ground. see how they fair

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If you already have a bell wire, try holding the radios close to the wire. This will act as a "leaky feeder" and give much better that line of sight underground.

I've used PMR sets underground (cave rescue practices) with mixed results ...

On a ~30 m pitch they were fine.

In a ~100m adit, with daylight visible, I couldn't communicate with someone immediately outside the entrance and we had to station someone halfway along the adit to relay messages.

In a 150m adit, lined with concrete pipes, again straight with daylight visible, it was not possible to establish communication at all.

Dave

With this on the subject of radio communication in awkward places, something I've used before on industrial telemetry links (450Mhz)where we didn't have line of sight due to a hill was a couple of aerials simply connected together with co-ax.
The aerial looking down the hill receives the signal and the other aerial re-radiates it in the direction you need- no electronics between at all. Just thought this might work for people trying to get a signal down a shaft. You will want proper resonant aerials but they would only need to be simple like a quarter wave dipole.
Regards Andy

We have used the Motorola GP 340 in a deep lift shaft, worked well. They are expensive (around £300 each plus chargers etc), but can be hired if you only want to use them occasionally. We hire ours when needed along with weatherproof cases. I used the same model whilst filming in an opencast coal mine, just put it in a strong plastic zip topped bag, still worked ok and didn't get caked in mud! I own a pair of BT Freeway walkie talkies, ok for short levels/shafts. About £50 including charger.

If you already have a bell wire, try holding the radios close to the wire. This will act as a "leaky feeder" and give much better that line of sight underground.

Should work a treat in Grove Rake, then :tongue:

MARK

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I use these.

http://www.amazon.co.uk/Binatone-Marina-900-Waterproof-Walkie/dp/B004EBV1FY 

Fine in a straight line, but as with anything over a few Hz, no-go through any substantial rock. Submerged multiple times without issue.

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I bought these earlier in the year for marshalling at our landrover show ....

http://www.ebay.co.uk/itm/6pcs-Walkie-Talkie-UHF-400-470MHZ-2-Way-Radio-16CH-5W-BF-888S-Earpiece-UK-Plug-/151644252152?hash=item234eb3a7f8 

Been good as gold so far with a decent range ....you'll need to program them for UK frequencies to comply with PMR legislation ....
Remembering to reduce the power setting from the full 5w 😉

I fix and look after Motorola GP 320 and 340's

They are extremely tough and reliable professional radios.
340's are 16channel and the 320's are single.
They are mil spec waterproof, and i have dropped one 6M on a steel floor, and got a mildly smashed battery. If you break the case. they are easy to change and cost about £10!

They are very cheap on ebay now. I'd go for the UHF versions for underground. Also as mistericeman points out you should program on the license free bands, a button can be programmed to toggle the power level to comply, and save battery. Or activate VOX operation.

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There are a few Chinese made 446 MHz PMR radios available through fleabay and other such on-line emporiums.
Although these sets are well built and perform very well indeed, they often exceed the UK power output levels for that band.
At present IIRC, 500 mW is the maximum allowed in the UK, whereas the Chinese ones are kicking out 4 to 5 Watts and invariably arrive programmed with non UK frequencies.
I have a couple of Baofeng BF 888 16 channel handheld walkie talkies that I use underground. They work well in stopes and also in long passages and shafts.
A USB programming lead is available for them with which you can reprogram each channel (to official frequencies) and also have other features to add such as voice scrambling.
At around £12.00 each they are good value, and if you know a little about this sort of thing, you can use features such as CTCSS and other exotic functions to personalise them.
BTW audio quality on these is excellent.
Waterproof? I think splashproof at best, but then RF and water aren't the best of bedfellows anyway.
Price includes a mains charger too.

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