UHF CB Channels

crew 153 · Post by **crew 153** » 11 October 05 2:59 pm

I have just picked up a pair of 1 watt UHF CBs mainly to give the missus peace of mind when I leave her in the car and go off looking for the cache. I was wondering which channel most cachers use when they are out and about? Also how useful are they?

Lt. Sniper · Post by **Lt. Sniper** » 11 October 05 3:11 pm

Channel 15 if I remember correctly.

Mr Router · Post by **Mr Router** » 11 October 05 3:15 pm

Pick a channel any channel

except ch 1-8 as these are repeater input channels and only should be used in duplex mode( using repeaters for covering much larger distances) where as ch 31-38 are repeater output channels.
In a nut shell do not use these channel on simplex as this causes heaps of probs chopping over repeaters.
And i think

most places have a ch 5 repeater that is only to be used to call for help in a emergency.

energizer61 · Post by **energizer61** » 11 October 05 4:54 pm

Channel 15 is the Norm, It was discussed here;
http://forum.geocaching.com.au/viewtopic.php?t=94
a few years ago

Also this newsletter http://alternatezone.com/ecoteam/files/ ... Issue1.PDF
mentions Channel 15

Cheers

Mr Router · Post by **Mr Router** » 11 October 05 5:37 pm

Ok so ch 15 is it , but if anybody wants to do a little test as to which ch works best you will find that ch 25 will give the best reception over a long but fixed distance, this has been tested many times, something to do with ant tuning? Sorry aerial.

riblit · Post by **riblit** » 11 October 05 9:49 pm

Mr Router wrote:Ok so ch 15 is it , but if anybody wants to do a little test as to which ch works best you will find that ch 25 will give the best reception over a long but fixed distance, this has been tested many times, something to do with ant tuning? Sorry aerial.

Interesting, do you have a reference to this?

GammaPiSigma · Post by **GammaPiSigma** » 11 October 05 10:32 pm

You may find this site useful.
 
Mike

GIN51E · Post by **GIN51E** » 11 October 05 11:12 pm

Mr Router wrote:Ok so ch 15 is it , but if anybody wants to do a little test as to which ch works best you will find that ch 25 will give the best reception over a long but fixed distance, this has been tested many times, something to do with ant tuning? Sorry aerial.

hmm i can see how it makes sense, to get the best possible signal and transmission you should tune the aerial the the transmitter/reciever and to do this you use a "SWR" meter,

now a hand held UHF unit has 40 channels and so i guess when they tune the aerial to the unit i thought they would use channel 20 for this as its in the middle of the freq range? but i wouldn't be surprised if i was wrong.

i carry 2 UHF units with me whilst Geocaching, now that i've seen this thread i'll make sure i keep it on ch15

crew 153 · Post by **crew 153** » 11 October 05 11:19 pm

Thanks everyone for the info. I will be using ch 15 as well.

Geof · Post by **Geof** » 12 October 05 11:38 am

For the full story download:

http://www.acma.gov.au/acmainterwr/aca_ ... s/cbrs.rtf

Remember no body "owns" any channel and they must be shared

.

Hounddog · Post by **Hounddog** » 13 October 05 12:34 pm

When manufacturers of UHF, and any other radio transceivers tune their untis they aim for the lowest SWR in the centre of the units channel range. So on the CB band this would be in the region of 15 to 25. Theoreticaly this should produce the best range on those channels but this would be hard to prove outside of lab conditions. Suffice to say the difference would be minimal.

The main reason we chose channel 15 is that it seems to be one of the least used by others on the band. The very thinking described above i.e channel 20 the best performer, makes it a better idea to stay away from the very centre.

With 40 channels being so affordable these days it seems silly to go and buy a handheld with anything less. Why restrict a user to just a few channels on a very congested band? The main advice I give here is on power. Do not buy a handheld unit with anything less than 1 watt output, 5 watts is preferable.

Not wishing to blow my trumpet but Snifter and I have been very active users of UHF and HF CB for over thirty years. There is not much about CB radio and it's usage that we don't know. I have installed very powerful UHF units in our cars, to allow us to get away with not using the very congested repeaters in most instances.

If anyone needs any advice on installations and what to buy for mobile or handheld, drop me a line.

Hounddog

crew 153 · Post by **crew 153** » 13 October 05 12:51 pm

Thanks Hounddog.

I have purchased a pair of Uniden 1watt handhelds. We are driving from Brisbane to Forster and back in the next few weeks with two cars and intend using them between the vehicles.

Hounddog · Post by **Hounddog** » 13 October 05 2:20 pm

crew 153 wrote:
I have purchased a pair of Uniden 1watt handhelds. We are driving from Brisbane to Forster and back in the next few weeks with two cars and intend using them between the vehicles.

You'll find 1 watt units work quite well for car to car on the hwy. What you might like to do experiment on just how far you can transmit if you get a bit seperated. I'm guessing on flat terrain probably up to 4 kms car to car "reliably", beyond this is asking too much of a 1 watt handheld unit. You should however, easily access repeaters even 20 kms away.

Have Fun

Mr Router · Post by **Mr Router** » 13 October 05 3:17 pm

As UHF cb channels are 25kc's apart ch 25 works right in there, And Riblet the only reference is quite a few test done many years ago, when you could turn the radio on without being told to f#$% off by some child or adult with a childs mind, But we wont get that one started!
UHF being what it is a good 6 odd inch bit of wire makes a great aerial, even better mounted in the middle of the car roof giving it equal ground plain, much better than mounting on the corners of the car as this tends to make the signal very directional.
We use a 1 watt handheld in GeoSuzie (I wont drill holes in it quite yet) and find it good as long as you can see the other car ( true line of sight) put a hill in the middle and no talkies, this also goes for repeaters with a handheld if you can see it all good, there are exception but unless there is a cache there climbing hills chasing repeaters is no fun anymore, unless you place while you are there!

Mr Router · Post by **Mr Router** » 13 October 05 3:28 pm

To Hounddog just fully read your string and we the very thinking have also been around a while to 1973-4 my first radio contacts were made, using one of the first Midland 23ch AM in the country after graduating from a 6ch Realistic, what a step up that was

And the difference to the ear over distance is quite noticeable on UHF over the channels, even away from the lab

Mr Router
Hey you did not live in Mt Peasant I mean Pleasant did you?