UHF radio alternative use?

Talking about distances more like up to a km away............thick bush...alternative to GPS for a quick bearing check

OK,

How's the temp down your way Graeme? Freezing?

I do the same with the GPS as stated in my post.

The reason for the original post was simply because when out prospecting the UHF is always on and the GPS is always off (after first creating the vehicles waypoint).......as it interferes with the detector signal.

Obviously I always keeps the vehicle position in mind but all of us at some time or another can easily have our bearings out by a few degrees and when some distance out (and in thick bush) it might be easier to double check where u think it is ( with a quick UHF PTT) as against stopping turning things off /on.

oooops

just read my original post..seems as though I didnt state my GPS ground rules ...thanks :)

Jaycar kit shown in my post below to do what Peter says here.

With the little use you would be giving the system I don't think the kids would twig onto it. With the number of CTCSS tones available it would take a lot of fathoming to work out which tone you were using. The kids would also have to be in hearing range of your truck to experiment as well.

True about the kids and the city but my mind moved to the bush and I didn't think about the tones. You would only need any noise to break the squelch out there. And a bit of "test test One Two Hello Hello" would do.

Never use the CTCSS tones myself. I find them annoying when in open chat sessions with multiple vehicles.

Quote -"Telstra had an alarm hooked up to their HF radio. If they got a selcall signal, the vehicle's horn would sound"

When HF SSB became the norm we also had the introduction of transistorised transceivers. Transistors also made it much cheaper to build selcall into our transceivers. These featured external alarms.

Back in the HF AM days the RFDS developed an interesting call system. Their emergency medical kits all came with a whistle with two barrels. If the remote customers had an emergency between scheduled operations they would use this whistle. They operated the PTT switch, held the mike near their mouth and then blew into the barrels of the whistle in turn. It took both tones from the whistle to activate the call system.

This is a little more refined system than I explained above but this audio alarm system has been in use for more than 70 years. Anyone can add it to their CB radio providing they don't do it in a manner that compromises the type approval of their equipment.

Thanks for informative follow-up, Peter.

Had seen a couple of those whistles, on stations I worked at, on Barkly Tablelands and East Kimberley. Think the transceivers were both Traegars.

In later years, had to use the single tone emergency signal a couple of times. Mt Isa base had suggested we extend call time from 15 secs to 30 or longer, to ensure "latching" at the base in bad atmospheric conditions. Was certainly one way to clear all chat off the frequency, once the alarm went off.

Were using Codan 7727B's then(and a newer Eprom(?) model, in blue-grey colour), until about 1995, when we put a UHF repeater at station. About that time, RFDS radphone and telegram services were suspended too, as "everyone" had a phone in outback by then. Massive loss of community after that, as no one would talk on HF regularly, but suppose that's progress.

You should write a blog about the changes in radio, you seen over the years, Peter,

Bob.

That was interesting guys.

Bob don't start him. He will go on about chrystal sets.