Thread: Stupid UHF repeater question

James,you havit in one.
Andrew

Some extra bits of info for you:

When you do duplex - your set transmits on the following:
ch 31 for ch 1
ch 32 for ch 2
up to
ch 38 for ch 8.

if you are in range ( 5 watts = 10 km ? ) the repeater receives that input signal (eg 31) and repeats it (on the main channel - eg ch 1) from 20 to 50 watts.

If a mountain is in the way between you and the repeater - no go. UHF likes line of sight type transmissions (generally).

Avoid those input channels for local use - car to car. Especially chan 35, as it's the input for the emergency repeaters. (they get annoyed, as I found out one day)

Langy

One comment I would add - range is almost independent of power, assuming a reasonable antenna installation, (and it is illegal to use more than 5w anyway) but is very close to line of sight, and if it is line of sight, the range can be well over 10km - I regularly get several locations close to 100km from here with no repeaters - I am on top of a hill, they are as well. And occasionally hear calls from aircraft that are well over 150km away but calling from perhaps 7,000ft. But on level ground around 10km vehicle to vehicle is the best you can expect, and in hilly country it can be only a couple of km or even less.
John

Hey JD
Do they actually police this 5W rule????
My UHF (purchased from ebay) is pushing out 25W,it has a 10W and 5W setting but I dont know how to change it.
Then again at least I can talk over the top of most truckies unless they have a Icom jobbie.
Andrew

Originally Posted by LandyAndy

Hey JD
Do they actually police this 5W rule????
My UHF (purchased from ebay) is pushing out 25W,it has a 10W and 5W setting but I dont know how to change it.
Then again at least I can talk over the top of most truckies unless they have a Icom jobbie.
Andrew

I have never heard of ANY of the CB regulations being policed, so the answer is probably not. The only advantage of extra power is the ability as you note to talk over the top of others, which is not really a very socially acceptable activity anyway. The increased power is not all that significant - since signal strength varies inversely with the square of distance, halving the distance is equivalent to four times the power. And as I commented above, increased power does not increase range, as this depends on line of sight.
John

Having extra power is not always that much of an advantage using a repeater anyway, you may be able to trigger the repeater, but your mate with the lower power set may not and hence not be able to talk to you. I see it all the time at work with handheld sets through the repeaters.


Martyn

Thanks everyone.

cheers

J

Originally Posted by Bushie

Having extra power is not always that much of an advantage using a repeater anyway, you may be able to trigger the repeater, but your mate with the lower power set may not and hence not be able to talk to you. I see it all the time at work with handheld sets through the repeaters.


Martyn

Handhelds have a double disadvantage - most of them are 1w or even 100mW, so they are way down on power compared to the "standard" 5W, and added to that the antenna is usually way worse than the one on a vehicle, let alone the one on a fixed station. So effectively the power of a handheld may be between one tenth and one hundredth the power of the vehicle installation, and in these circumstances, yes, power does start to affect range. My handheld though has a low and high power switch - 1W and 200mW, and in the fifteen years I have been using it there has probably been less than half a dozen times where I lost communication on the low power (normally used to make the battery last longer) but could re-establish it on high power.
John