HF/UHF and Satphone advice

**JDNSW** · 15th June 2007, 05:55 AM

Just a comment on the EPIRBs. The original type (developed to locate downed pilots during the Vietnam war) broadcasts a signal on 121.5 and 243MHz, these being the civil and military emergency frequencies respectively. All aircraft with two VHF sets (includes all airliners) normally have one tuned to this all the time (and use it for gossip), which together with high cruising altitude of pressurised airliners ensured coverage almost everywhere. When a signal is detected, the alarm is raised, and a search pattern is flown at decreasing altitudes to locate the position. Different modulation is used (or supposed to be) for Land, sea and air beacons, and some also have VHF transceivers built in.
Around twenty years ago several satellites were launched which detect these signals, and relay them to national search and rescue centres. They also allow the position to be determined using the doppler shift of the signals, but the accuracy is limited by the frequency stability of the beacon. With their proliferation in recent years, false alarms have become a major problem, and to alleviate this and to improve accuracy (and hence reduce costs of searches), a new set of satellites was launched around ten years ago. These use a higher frequency beacon with a more stable frequency, and each beacon transmits an identification code, and this is registered when it is sold (so that it is immediately clear who is missing - or responsible for the false alarm). They are also more expensive.
The old satellites will be decomissioned as mentioned, but beacons would still be detected by aircraft. Whether such signals would be acted on after satellite decomissioning is a moot point, but I'm guessing that if in a remote area they would be.

John

**DirtyDawg** · 15th June 2007, 08:09 AM

I run a 35w output UHF and carry an EPIRB when going remote areas..oh and a lot of fresh water

Nairbo · 1st July 2007, 07:38 AM

Originally Posted by nw393y

I have a Telstra Satphone, works great anywhere in the world as long as you're outside.

Don't sign up for a Telstra Satphone account, minimum cost is $30 per month. If you're not going to use it much just go to a telstra shop and ask for a standard (NOT nextG) GSM SIM card with global roaming enabled. These plans start at just $10 per month.

Telstra don't really acknowledge this works from my experience, but then again most of the telstra staff I spoke to - including those in the Sat division - didn't seem to really know what a Satphone was!

Nathan

That GSM SIM card info is gold I have been paying $30 per month for almost 2 years , my contract will finish in 4 weeks and then I will be talking to Telstra , I was close to getting rid of the sat phone due to the cost of it just sitting here doing nothing for months at a time,thanks Nathan

**Bush65** · 15th July 2007, 08:27 AM

Originally Posted by nw393y

I have a Telstra Satphone, works great anywhere in the world as long as you're outside.

Don't sign up for a Telstra Satphone account, minimum cost is $30 per month. If you're not going to use it much just go to a telstra shop and ask for a standard (NOT nextG) GSM SIM card with global roaming enabled. These plans start at just $10 per month.

Telstra don't really acknowledge this works from my experience, but then again most of the telstra staff I spoke to - including those in the Sat division - didn't seem to really know what a Satphone was!

Nathan

I have HF but hired an Iridium sat phone for a recent trip.

For interest I tried the sim card from my telstra nextG turbo modem that I use with my laptop. Global roaming was enabled on the nextG modem and it worked fine in the Iridium phone for making a call - I did not try recieving calls.

Now I will start looking around for an Iridium sat phone.

**Hymie** · 15th July 2007, 12:02 PM

Originally Posted by Bush65

I have HF but hired an Iridium sat phone for a recent trip.

For interest I tried the sim card from my telstra nextG turbo modem that I use with my laptop. Global roaming was enabled on the nextG modem and it worked fine in the Iridium phone for making a call - I did not try recieving calls.

Now I will start looking around for an Iridium sat phone.

I bought 2 Irridium phones with 60 seconds of talk time on each of them from Graysonline Auctions.
They had a big stack of 20 or so and they went for $420 each.
Apparantly the NAB bought a heap for the impending Y2K global meltdown in 1999 and they are trickling into the market place now.
Occasionally a few pop up on Eb@y.

**waynep** · 15th July 2007, 03:10 PM

As has been mentioned already, the new EPIRB system will be much more accurate in giving your position than the old one. The old system could only report your position by satellite to within 20km or so then they had to zero in using ground parties or aircraft. This meant it could could take some time to get assistance. The new system also sends an identifier code that tells them exactly who has activated it.
The new EPIRB is basic cheap insurance if you go remote infrequently.

If you're going to be in really remote areas a lot the simplest way to go is a handheld SatPhone. They can be hired. Some 4WD clubs also have them but normally only allow them to go out on official Club trips.

HF is good if you are a social person because you can chat to other travellers on the VKS737 network totally free of charge. It will take more effort and space to install and you need a little more technical nouse to use it.

Nairbo · 6th September 2007, 06:03 PM

Originally Posted by nw393y

Don't sign up for a Telstra Satphone account, minimum cost is $30 per month. If you're not going to use it much just go to a telstra shop and ask for a standard (NOT nextG) GSM SIM card with global roaming enabled. These plans start at just $10 per month.

Nathan

I tried this and it just comes upon the phone screen "INVALID ACCOUNT" ?

**Blknight.aus** · 6th September 2007, 06:59 PM

My permanant car install is a single UHF/AM combined unit which has good range on am and has been of good use the AM band is still used but mainly by ham radio buffs so you can get in touch.

Uhf is good for not much better than LOS.

The satphone Id hire if I needed it but I have a few friends that have portable HF sets that are radphone compatable...

IMHO a good UHF/AM SSB takes care of your convoy coms and beyond that the satphone is the ducks danglies.

Mind you last time I was on HF sersiously I had a good conversation with some bloke in russia doing exactly what I was doing... Radio picket on an exercise.. through broken english over a 2 hour period I learnt that all AJ's gripe about the same stuff...

**jik22** · 6th September 2007, 08:26 PM

Originally Posted by Blknight.aus

IMHO a good UHF/AM SSB takes care of your convoy coms and beyond that the satphone is the ducks danglies.

Since posting this originally, I put a UHF in the car for the trips out, but haven't made a decision on Satphone vs. HF yet, as we haven't managed to find the time for a long trip into the middle of nowhere.

I'm going to do my amateur license, so if I can find a set that will also do the RFDS and 737 frequencies, I'll buy one, if not, it'll be Satphone (Probably hired) when we do venture further afield. Plus a cheap EPIRB!

**Blknight.aus** · 6th September 2007, 08:44 PM

some satphones Actually have an epirb function buried inside them... scroll through some menus and apparently its there...

Im not sure how much I trust that info as It was given to me by a yota driving fishing buff but If I was designing a sat phone sure as shooting Id put that feature in along with a feature that would allow it to be turned on by someone else over the satelight system.. Missed your scheduled call in time by 24 hours? lots of alarms ring then the eprib turns on.

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