For all high tech electronic equipment including GPS, PLB, chargers, phones, computers, software. Discussion of simple electrical devices such as torches, belongs in the main 'Equipment' forum.
Mon 29 Dec, 2008 10:20 am
I've often wondered if one could combine the two hobbies . With the talk of the EPIRB beacons being so costly .. why not take along a tiny HF or VHF radio. With the introduction of the 'foundation license', a ham radio license is very easy to get now ..no morse code test any more .
Possible HF disadvantages
For the lower HF bands ..you need a long wire for a antenna.. but a 1/4 wave sloper does work .
Battery requirements ..
These days ..the lower HF bands are pretty deserted... not much activity.
Propagation varies with day/night .
VHF Advantages .
There are VHF repeaters dotted around Tasmania ( on mountain tops ) .. you could make up a very light portable directional yagi antenna.The 'line of sight' ranges possible are amazing .
Mike
Tue 30 Dec, 2008 6:36 pm
We did an overnight walk on Mt Montgomery in the Dial Range NW Tas. in I think 1977. The purpose was to see how far we could communicate on the 5 watt CB radio. We took an unsealed wet cell 12 volt car battery, a SSB 27MHZ CB radio and a mobile antenna with 4 x copper wires as a 1/4 wave ground plane. I remember talking with the then illegal CB operators all along the N.W. coast from Stanley to Bridport and into Launceston. Must have been the one of the first CB transmissions from that mountain. I don't know how many people have spent the night up on that mountain top. Great fun for a 15 y.o.
Bill.
Tue 30 Dec, 2008 8:48 pm
Hi Bill
Lugging a heavy car battery around , sounds ideal for a 15 year old .
During WW2 , the army signallers set up a chain of signalling lamps around Tasmania, eg on Mt Barrow and 1 or two other mountain tops ..ending with Mt Wellington ..They would flash messages from Launceston down to Hobart in minutes .. just with lamps . Speeds were kept to about 10 WPM .. with a incandesant filament, the speed is limited by the on - off lapse , or slow switching . Ranges possible with lamps are 60 miles or more , line of sight. The lamps were LUCAS lamps .. WW1 era , still in service in WW2 , narrow focal point .
27 mhz is just about dead . There is still activity on UHF cb ..but its useless in the city because of the out of control masses who use it.
I've just been listening to the Sydney Hobart race on 6516 khz ... I was listening ten years ago when that horrible storm hit the fleet ... lots of excitement , the radio was buzzing with maydays etc. Not this year , very quiet thankfully.
Mike
Mon 12 Jan, 2009 1:01 pm
The sending of light messages across Tasmania reminds me of the old ex WW2 British Bedford fire trucks that the Tas Fire Service (then the Rural Fires Board)got in the 1970s. They had a huge capacity PTO driven pump that could pump at a high pressure and volume. It was said that as an exercise, a series of these were set up and and pumped water across England from East to West!
I'm back in Victoria after 3 nice weeks back in Tasmania, I took a UHF CB and some $69 UHF hand helds (100mW?)
I find them handy in the bush especially when with other 4WDs or with a group of walkers.
I was able to chat on the hand held from Prospect Mt near the Cradle Link Rd, to one of the Shuttle buses on the Cradle Mt Rd, somewhere between the Cradle Mt Lodge and Snake Hill. Must have been 10+ km.
You are dead right, here in Melbourne the UHF channels are full of the most idiotic ranting imaginable, but the outer suburbs and country areas are ok.
In the city I only use UHF walkie talkies for short distance communication, mainly at work (Industrial electrical automation etc)
I passed my novice amateur exams many years ago but never got on air, I dont have much radio gear at the moment, I had a HF Barlow Wadley receiver, but maybe when the budget allows....!
Bill.
Tue 13 Jan, 2009 10:02 am
billyboy wrote:The sending of light messages across Tasmania reminds me of the old ex WW2 British Bedford fire trucks that the Tas Fire Service (then the Rural Fires Board)got in the 1970s. They had a huge capacity PTO driven pump that could pump at a high pressure and volume. It was said that as an exercise, a series of these were set up and and pumped water across England from East to West!
I'm back in Victoria after 3 nice weeks back in Tasmania, I took a UHF CB and some $69 UHF hand helds (100mW?)
I find them handy in the bush especially when with other 4WDs or with a group of walkers.
I was able to chat on the hand held from Prospect Mt near the Cradle Link Rd, to one of the Shuttle buses on the Cradle Mt Rd, somewhere between the Cradle Mt Lodge and Snake Hill. Must have been 10+ km.
You are dead right, here in Melbourne the UHF channels are full of the most idiotic ranting imaginable, but the outer suburbs and country areas are ok.
In the city I only use UHF walkie talkies for short distance communication, mainly at work (Industrial electrical automation etc)
I passed my novice amateur exams many years ago but never got on air, I dont have much radio gear at the moment, I had a HF Barlow Wadley receiver, but maybe when the budget allows....!
Bill.
Hi Bill.
Interesting . Those Bedfords may have been RL's .. a very good 4X4 made in the early 1950's and production continued right into the 60's . Still in British army service in the first gulf war. In fact, I'm positive they would be RL's . The army here didn't buy them..but the Kiwi's did .
In the UK , during the cold war , they built hundreds of Bedford GREEN GODDESS pumper trucks ..in case of NUCLEAR war . These are still in storage , ready to go BTW ....fully maintained ..old 1950's vehicles ... the photos of them lined up in storage are amazing .... they look brand new still .
Yep ..I've got those cheap UHF hand helds too , they put out about 1/3rd of a watt ... they work very well .. if you could rig up a folding yagi antenna with some gain.. you could take it in your back pack on bushwalks .
The Barlow Wadley is a famous receiver , made in South Africa from memory .. they sold well here . I've played with one or two but never owned one . The Wadley loop design was taken up by RACAL in the UK .
Mike
Tue 20 Jan, 2009 9:20 am
Is there much second hand receiving gear on the market?
I occasionally look in the Melbourne Trading post or e-bay for HF receivers or VHF/UHF scanners, never see much.
I remember loads of people buying this sort of stuff in the late 1970s/early 80s, must be plenty of FRG7s etc in peoples sheds.
The idea of a portable yagi interests me, maybe I should dig out those old antenna design books again.
I built a 3 element yagi for the 27 Mhz CB and had good sucess. When the 'skip was in' was often able to talk from Tas to the eastern mainland states sometimes US, NZ, Sth Africa, SE Asia if the channels weren't too full.
The main problem was the huge physical size of the antenna, Dad wasn't too impressed with me up on the tile roof with the beam on a length of waterpipe attaching it to the chimney! A 477Mhz yagi would be much more easy to handle.
Bill.
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