Alan de Enfield Posted January 8, 2019 Report Share Posted January 8, 2019 21 minutes ago, ditchcrawler said: I am to far out of date to comment. Got my licence about 40 years ago with an add on to talk to helicopters. It is surprising how far a hand held will go if its high enough. We had a case of an American drilling company hiring hand held for use on the rig only but they were supplied set to the same frequency used by Gt Yarmouth Lifeboat. Well we were over 60 miles away but once a chap took it to the top of the drilling derrick he was being picked up in Yarmouth. Like wise I talked to helicopters that had just taken off from the Indefatigable platforms from the helideck in the Leman gas field VHF = Line of sight. Line of sight when you are up a few 100 feet is quite considerable (particularly over the sea). Link to comment Share on other sites More sharing options...
ditchcrawler Posted January 8, 2019 Report Share Posted January 8, 2019 15 minutes ago, Alan de Enfield said: VHF = Line of sight. Line of sight when you are up a few 100 feet is quite considerable (particularly over the sea). Yes, surprising how little power is required Link to comment Share on other sites More sharing options...
Alan de Enfield Posted January 8, 2019 Report Share Posted January 8, 2019 2 minutes ago, ditchcrawler said: Yes, surprising how little power is required Agreed - the little Personal Locator Beacons (PLB's) are 0.25w and can be picked up by aircraft at 30,000 feet 100s of miles away. My 3w Cobra hand held was OK for about 20 miles if the receiving station aerial was high enough. My 5w handheld doesn't get any further just has a 'bit more power' when it arrives. Link to comment Share on other sites More sharing options...
Jess-- Posted January 8, 2019 Report Share Posted January 8, 2019 11 minutes ago, Alan de Enfield said: VHF = Line of sight. Line of sight when you are up a few 100 feet is quite considerable (particularly over the sea). UHF = line of sight (even more severely than VHF) on the ground transmitter range can vary from under a mile in cities to around 10 miles in open country however if you get a transmitter up very high you can cover huge ranges with very little power. A test transmitter of mine was sent up to 24,996 feet (annoyingly missing the 25,000 feet target by 4 feet), the transmitter power was 1mw (10 times less than a car alarm keyfob) yet the signal from it was received across most of europe Link to comment Share on other sites More sharing options...
Sea Dog Posted January 8, 2019 Report Share Posted January 8, 2019 (edited) 59 minutes ago, ditchcrawler said: It is surprising how far a hand held will go if its high enough. You make a good point - it's not simply about power. Depending on how high the frequency is, hand held radios are line of sight or even 4 thirds line of sight. Get high enough, and on a good day... The radio buffs here will know that radio operators who know about RF propagation and atmospherics can get to the other side of the world on 5 watts on HF. Edited to add: Oops, I replied to DC and then saw the intervening posts! Sorry chaps (but at least we agree) Edited January 8, 2019 by Sea Dog Link to comment Share on other sites More sharing options...
Jess-- Posted January 8, 2019 Report Share Posted January 8, 2019 1 minute ago, Sea Dog said: The radio buffs here will know that radio operators who know about RF propagation and atmospherics can get to the other side of the world on 5 watts on HF. Not quite... 10 watts from uk to australia was my best with voice, punching the power up to my 400w limit made almost no difference (apart from making my touch activated lights in the bedroom look like strobe lights) Link to comment Share on other sites More sharing options...
Alan de Enfield Posted January 8, 2019 Report Share Posted January 8, 2019 18 minutes ago, ditchcrawler said: Yes, surprising how little power is required 6 minutes ago, Jess-- said: UHF = line of sight (even more severely than VHF) on the ground transmitter range can vary from under a mile in cities to around 10 miles in open country however if you get a transmitter up very high you can cover huge ranges with very little power. A test transmitter of mine was sent up to 24,996 feet (annoyingly missing the 25,000 feet target by 4 feet), the transmitter power was 1mw (10 times less than a car alarm keyfob) yet the signal from it was received across most of europe I think that folks generally think that "more power is good" when in fact quality and height of the antenna are the controlling factors for distance. I used to be able to regularly reach Italy on 27 Mhz AM, with 5 watts. The hard part was getting thru the 'noise' so that my signal was picked up rather than anyone else's signal. Double the power and move onto side-band and it was 'easy'. Power gives 'signal strength' and 'signal quality' it does not really affect range. 1 minute ago, Jess-- said: Not quite... 10 watts from uk to australia was my best with voice, punching the power up to my 400w limit made almost no difference (apart from making my touch activated lights in the bedroom look like strobe lights) I used a 400w Zetagi amp and found the same - use the 'power' to get the QSO, then turn it down until you could make easy conversation. Australia was not an uncommon QSO. Link to comment Share on other sites More sharing options...
Sea Dog Posted January 8, 2019 Report Share Posted January 8, 2019 13 minutes ago, Jess-- said: Not quite... 10 watts from uk to australia was my best with voice, punching the power up to my 400w limit made almost no difference (apart from making my touch activated lights in the bedroom look like strobe lights) Ten watts is still pretty good though, eh? My experience is from way out at sea and 24/7 operation with military operators (with military kit and aerial arrays) who relished the challenge to ease the tedium. Can't say we did UK to Australia on 5w though - but the other side of the world didn't necessarily have to mean the full 12000 miles to impress me. Some of those guys really knew their game, but its a dying art at that skill level due to the convenience and data rates offered by Satcom. Link to comment Share on other sites More sharing options...
Alan de Enfield Posted January 8, 2019 Report Share Posted January 8, 2019 On 07/01/2019 at 14:19, barmyfluid said: I've got a baofeng uv-5r, which you can pick up new for about £25 and reprogram to the UK marine VHF channels Are you still using the OEM 'Rubber-Ducky' aerial ? If so try using the Nagoya NA771 (about 99p on ebay) you will be surprised by the difference in bot RX & TX https://www.ebay.co.uk/itm/Baofeng-UV5R-UV-82-144-430MHz-Dual-Band-Antenna-NA771-SMA-10W-Female-Nagoya-UK/132538490357?epid=2159908666&hash=item1edbe8ddf5:g:0dkAAOSwy0JaKkBQ:rk:2:pf:1&frcectupt=true The programming software you alluded to is probably "Chirp" The UV5R also allows you program for the Coastguard "Channel 0" and all of the Search & Rescue (SAR) Channels (both land and sea). in addition to all of the existing (and new 2019) Marine channels. The UHF channels can also be tuned in to the PMR446 channels so it is a case of 1 radio does it all (but not aircraft). Link to comment Share on other sites More sharing options...
barmyfluid Posted January 8, 2019 Report Share Posted January 8, 2019 2 hours ago, Alan de Enfield said: Are you still using the OEM 'Rubber-Ducky' aerial ? If so try using the Nagoya NA771 (about 99p on ebay) you will be surprised by the difference in bot RX & TX https://www.ebay.co.uk/itm/Baofeng-UV5R-UV-82-144-430MHz-Dual-Band-Antenna-NA771-SMA-10W-Female-Nagoya-UK/132538490357?epid=2159908666&hash=item1edbe8ddf5:g:0dkAAOSwy0JaKkBQ:rk:2:pf:1&frcectupt=true The programming software you alluded to is probably "Chirp" The UV5R also allows you program for the Coastguard "Channel 0" and all of the Search & Rescue (SAR) Channels (both land and sea). in addition to all of the existing (and new 2019) Marine channels. The UHF channels can also be tuned in to the PMR446 channels so it is a case of 1 radio does it all (but not aircraft). I still have it, but I usually use it with my own homebrew antennas, and I've some big extendable ones I can tune to whatever band I'm obsessed with at the time. It's an amazing amount of radio for the money, only just started looking at the marine uses, though I'd not want to trust it out on the lumpy stuff as a primary unit - good backup though. Yep, it is Chirp, I found a config for marine use on YBW somewhere, saves a fair bit of programming. Link to comment Share on other sites More sharing options...
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