HF Radio Frequencies

Hi

Website is www.vks737.on.net

Hi again, we will be on the central road in June so if you a on
give us a call on 9754 we will be scanning in vks

regards

Thanks Bill,I am doing Coober Pedy to Laverton,Wiluna,nth to well 33,thenwest to Newman-Exmouth in June.Thanks for the info on the HF radio,may come in handy on the Anne Beadell "H'way".Will subscribe to VKS 737... Thanks to other guys also for info.. Cheers John W

If you want value for money, friendly service and all of the services that VKS and HFoZ offer on one network then I suggest to join HF Radio Club

$65 dollars per year
$0.50 per min Phone calls and no monthly fee.
$0.20 SMS to Mobile messages
Free Unlimited GPS Logging

And your family and friends can see your GPS positions via the internet at NO CHARGE at any time.

Skeds run twice per day from the east cost and west cost with a central logging system.

Brand new, State of the art Telephone Interconnect Systems.

Have been with them for years and they are the most helpful club of them all....

They also are developing new systems to complement there current network which we will see before the end of the year.

HF Radio Club
www.hfradioclub.com.au

Does that mean you cannot send out warnings from the SES etc?

No - any advice to hand re potential risk to travellers from whatever cause is broadcast at the front of skeds. Some road closures and adverse weather etc. may not come up in a sked discussion though, unless someone calls in from the affected area.

G'day Jedo,
This is from my Codan manual (i think). it gives an idea of which frequency to use for day or night.

Frequency Day kms Night kms
3995 400 800
5455 500 1000
8022 800 1600
11612 1200 2400
14977 1500 3000

Often later at night there is a fair bit of interference I am told from indonesian fishing boats.
The HF installation needs to have a good earth and aerial well placed. I have an old 80 ser 1Hz so no electronics. I hear the 100 with common rail fuel injection have problems with the motor running. Don't have your fridge or any inveretrs running, change the orientation of you vehicle.
Sometimes it isn't good and you need patience, but you can guarantee someone will pick you up and relay any messages.
You can also 'ping' beacons to see what the reception response is like - off skeds of course.

Cheers,
VKS 737 Mobile 0967
Bill

Thanks very much for that Bill...

Gives me something to work with...
I have a GU Patrol and have tried the "earthing" thing with broad braid - and got 'more' static noise, so I gave that away...
The Waeco is right next to the big box in the rear of the vehicle and doesn't upset the Codan at all..??!!
It is only very seldom I get a response revert signal from Alice or Adelaide from Broken Hill...
I think I live in 'no-man's land'... LOL
Have copy/pasted your Freq/Dist data and will use as reference.
Thanks again
Jedo

Radio propagation is almost a science in itself. But I will simplify a lot of it that may help you understand why you may hear someone and they cannot hear you. I will not go near the advantages and shortcomings of antennas. That is another topic.

Consider a station transmitting from Alice Springs. The time is noon.

The ionosphere is a layer around the earth that acts as a "rough" mirror to radio signals. The time of day and frequency affects how a signal is reflected. Some go straight through and into deep space. Others get trapped in the layer and don't pop out until thousands miles away. Thus sending Auckland taxis to Sydney addresses. This is NOT A MYTH.

It is also not a perfect mirror and sometimes if you hear a signal that has been reflected and call back your signal may end up on a different reflected path and miss the base station completely.

That's what you experienced in your example. The antennas can also make a big difference. The best you can do for mobile is get a good wet (!!!!) earth and just try again. I do not know if 4WD HF'ers are permitted to put up wire antennas but if you are, then using a wire dipole or even a fence pointing in the best direction can help. I tried a fence once in 1983 and spoke to a California station using only 1.5 watts on 28 Mhz.

The rule of thumb for picking HF frequencies is: at night use lower frequencies. This is mainly why at night we hear more fishing boats. Note for overseas contacts it depends on what the ionosphere is doing between the two locations.

I hope this helps

Phil

Note: I had to contact Tasmania from Melbourne for a particular award and after trying for several months we finally succeeded by pointing our antennas (big beams) directly away from each other and went the "long way round". We had to be careful of the time of day along that whole track as well. Got there and we both got the award.

Frequency Day kms Night kms
3995 400 800
5455 500 1000
8022 800 1600
11612 1200 2400
14977 1500 3000

- simple guides like this are wrong because Ionosperic Propagation varies with Sunspot Activity and that has an 11 year cycle.

We're currently at the bottom of one cycle so you have to use lower frequencies than "normal". e.g. at night 8022 has a skip rang of 3000km, so at night for 1000km you would have to use 3995.

Mike

I wouldn't say the chart is wrong because it is just a schedule. Its how we should use the chart that should be explained a bit. The experienced HF user will know instinctively how to use that chart but to the inexperienced user who needs a couple of "user hints" or rules of thumb.

As you know to accurately predict which frequency to use at what time, well we are then getting into a difficult science. I had an excellent job once as system controller for a defence communication centre. From ionosphere charts and guides I had to select the frequency. The boffins used to give us their best bet but it wasn't always correct. So you had to take the charts with a grain of salt, flip a coin, see what the tea leaves say and have a go. I enjoyed that type of job twice. Once in Oz and then another quite exciting time in the asian region where mother nature, just for fun, tossed in tropical storms, lightning etc as well.

I would also forget entirely about the distance column. Why? Because you may be in the "skip" zone for one base but perfectly located to pick up another base of realy station.

For those trying to figure out which sched to use may I suggest three things:
1. start low at night and work your way up in frequency and then go back low and start again.
2. scan them all and pick the best. and
3. keep an ear out for any station that may be able to relay for you.

Phil

Umm.. Thanks... for that info...
You fellows surely know your stuff. But I am both blinded and intrigued by the science:
Phil - Thankyou... Am aware of the vagaries of the ionosphere/time of day/etc and utterly intrigued by your refernce to a "wet" earth...
I don't even have 'dry' earth - so would you explain futher..??
And, Yes, lower freq at night... but read on...
Mike DiD - Yes, I have a slight knowledge of how cyclic sun-spot activity affects HF radio transmissions - but this knowledge is largely Academic to me as there is little I can do to effect nuclear reactions on the Sun... And VKS737 only use nominated frequencies to conduct Skeds - and 3995 is not an option...
I would imagine (could be very wrong) that mobile HF owners who are subscribed to clubs such as VKS737 tend to monitor the frequencies nominated by the individual clubs - the 'popular' freqs used on Skeds - 5455 and 8022... and some higher frequencies...
I've not seen 3995 noted as a Sked Frequency...
Jedo

Run a bit of braided wire from the car's body to a metal rod stuck in the ground. Then about the wet bit. I thought that after a few cans of beer or glasses of wine that there would be an excellent source of moisture for you to "wet" the ground around the metal rod.

Do need to give more details here!!!!!!!

Just stick to the three hints at the end of my previous post. Don't worry about anything you cannot control.

100 series have direct fuel injection NOT COMMON RAIL