Search & Rescue Incident - Ground & Air Radio Coms

[m0lsx]

The distance you are able to hear a mountain rescue unit from is going to vary very dramatically.
On VHF the topography (or if you prefer the terrain) between receiver & transmitter make a massive difference. If the path between you & them is clear sky, then the distance could be many tens of miles, even on FM. But if they are low & for example a few buildings are in the way, a few hundred yards is possibly too much.
Even driving up a slope towards a transmitter site can lead to a loss of signal. I know one location where a long gentle slope has a signal from a distant repeater across it all except for the last half a mile. And there, you are in the shadow of the top of the slope & on that last & highest section, you just loose contact as a result.

[Radioshane]

thanks molsx and I don't thin'k I could pick them up near me as I think the nearest mountain rescue team is north Yorkshire moors and as vhf is line of sight even with aerial on chimney that would be about 30 miles past pickering so couldn't do it I think you would have to be close to one of the national parks

[Radioshane]

molsx i'm thinking of staying in some digs to watch the joint warrior exercises in October in helensburgh I know there is a mrt base near hawick
what's the furthest away do you think you could pick them up?

[Altomar718]

If you have shortwave, the SAR frequency is 5680Mhz - This used to be the control in Kinloss, Scotland and RAF Chivenor in North Devon which has recently closed. It has been taken over by Bristow

[Davie Boy]

I like when the tetra transmissions can be heard from 7:43 in the video....

[RadioWatcher]

I like when the tetra transmissions can be heard from 7:43 in the video....

Hello that is Polycon not tetra, with HF bleedthrough.
RW

[thelad]

Hello that is Polycon not tetra, with HF bleedthrough.
RW

Hello.
Nope davie boy is correct its Tetra, the Airwave system is being patched into the Polycon for the crew to hear.
My mates a winch man at Bristow.

TL

[G4RMT]

I sometimes think we get too hung up on the names of the systems, when the important thing are the sources. In the control rooms, none of the sources on the screen are ever labelled Tetra or even Airwave. isn't it a bit like getting a FaceTime on your phone, and saying "hang on, Ive got a 4G EE coming in" - wouldn't you usually just say what your phone calls it, like "FaceTime from mum" - I bet many Policemen don't even know what Tetra is, let alone Airwave. If the source comes up on a display in the helicopter, it is going to say VL or whatever callsign the County force are using.

[thelad]

I have heard the Bristow crews in the past when contacting the MRC Centre on HF say "will contact you via Airwave" i asume thats when they have to pass sensitive details so i would think the crew understand Airwave.

[Davie Boy]

Hello that is Polycon not tetra, with HF bleedthrough.
RW

Hello.
Nope davie boy is correct its Tetra, the Airwave system is being patched into the Polycon for the crew to hear.
My mates a winch man at Bristow.

TL

Aye.... The Tetra beeps are a big giveaway....

I didn't know it was a patch though.... I just thought you could hear the tetra in the background on the polycon.... Very interesting