0.7watt 2 pack or 1 watt uhf handheld

Submitted: Sunday, Aug 28, 2005 at 07:35

ThreadID: 25929 Views:3116 Replies:5 FollowUps:2

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sxc_thing

hey guys (girls) i wanna buy sum more radios but dont know if i should get a 1watt or two 0.7 watts there just for fun nothing big i all ready have one 5watt handheld. just need them for when i go out with mates we can talk or to use in cars when going out on a daytrip any idea's i all ready have 5watt and 4 0.5 watts but i need sum more but betta. not sure if there is anything thing diff about 0.5 and 0.7 radios

thanks people

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Reply By: Member - Chrispy (NSW) - Sunday, Aug 28, 2005 at 08:01

Sunday, Aug 28, 2005 at 08:01

I just (yesterday) bought a twin-pack of the 1.5 watt jobbies - the Uniden UH060sx-2 "deluxe pack". I found that after looking at the 0.7 and 1 watt units, they were really plasticy and didn't look solid enough to last in a 4WD cabin. A bit more expensive, but much more solid units. The range is far better obviously, as we powered up all three varieties and I was talking to people that I knew were around 7 km's away - and not exactly in line-of-sight either - but only on the bigger ones.

They're all good units though, and for spotting or recovery work back to a car with a built-in UHF they all work great. If you're looking at using them in convoy situations and it's a dry dusty day - you might be spreading out a bit far for the 0.7 and 1-watt units..... especially if it's hilly country.

Cheers
Chris

AnswerID: 127149

Reply By: Utemad - Sunday, Aug 28, 2005 at 08:57

Sunday, Aug 28, 2005 at 08:57

If you already have 5 radios and you need more for talking in convoy, why don't you get your tight arse mates to buy their own radios?

AnswerID: 127152

Reply By: Boo - Sunday, Aug 28, 2005 at 09:08

Sunday, Aug 28, 2005 at 09:08

Hi,

We have two sets, 1 DSE (Dick Smith) which is 1.7w and the other set we got from cash converters (Xpedition) also 1.7w. Both sets work well, we've used them in the cars in convoy with others around town, and whilst heading off road. They are supposed to work up to 5km range and I'm sure they do. We've also tested a handheld against our in car unit and it still worked well even with the distance and hills in between, definately not line of sight.

After having ours, I would suggest you buy one of reasonable power otherwise you will be disappointed.

Kerrie

AnswerID: 127154

Reply By: VK3CAT - Sunday, Aug 28, 2005 at 10:50

Sunday, Aug 28, 2005 at 10:50

Hi scx_thing. Suggest that you read a
previous thread
The difference in power output from .7 watts to 1 watt will make bugger all difference. Of more benefit (transmit distance) will be the antenna efficienies / inefficiencies on the different units. Obviously a more robust construction will be advantageous. If available, radios that use AA batteries rather than AAA batteries are better due to the greater battery capacity.
Cheers, Tony.

AnswerID: 127163

Follow Up By: Nudenut - Sunday, Aug 28, 2005 at 18:34

Sunday, Aug 28, 2005 at 18:34

assuming antanae have same efiiciencies would would have more output

a transmitter sending 5 watts to antanae
or
15 watts?

FollowupID: 381736

Follow Up By: VK3CAT - Monday, Aug 29, 2005 at 17:24

Monday, Aug 29, 2005 at 17:24

Nudenut.
A transmitter outputting 5 watts into an antenna will put out 3 times less power than a transmitter outputting 15 watts into exactly the same type of antenna.
The difference in output power is about 4.5dB
Antenna gain is a different thing as it works on both transmit & receive & is a passive thing (doesn't require any power).
Antenna gain is also measured in dB (decibels) and is either refered to as dBi (referenced against an Isotrophic antenna which is an ideal antenna in free space that is impossible to achieve) or dBd (referenced against a 1/2 wave dipole)

OEM Hand held antennas are usually well short of a 1/4 wave so should not be credited with any gain at all. Some are actually better attenuators than radiators!

For our practical mobile installations, a better reference antenna is the 1/4 wave ground plane. According to the Radio Theory hand book page 244, a 1/4 wave ground plane antenna has about 1/2 a dB of gain over the isotrophic antenna 1/2 dBi. A dipole antenna has about 2.7 dBi gain over an isotrophic antenna. Common UHF antennas are the 1/4 wave, the 5/8 wave and collinear antennas which are generally multiple 5/8 waves joined end to end.
A 5/8 wave antenna will effectively have around 2.7 dB gain more than a 1/4 wave which will nearly double the Effecive Radiated Power (ERP) - the equivelant of having 10 watts out put instead of 5 watts. Two 5/8 waves will add about another 3dB of gain and give an ERP of 20 watts. Four 5/8 waves will give about 9dB of gain for around 40 watts ERP

So 5 watts into a 1/4 wave will give 5 watts ERP.
5 watts into 2 x 5/8 waves will give 10 watts ERP
15 watts into 2 x 5/8 waves will give 30 watts ERP

Antenna gain is not magic. It is achieved by concentrating the Radio waves into a narrower stream (by lowering the radiation pattern). This is simmilar to adjusting the nozzle on a garden hose from a spray (1/4 wave) to a jet (2 x 5/8 waves)
Hope that this was not too technical for you & has explained things somewhat. When purchasing and comparing antennas, always check the gain reference of dbi or dBd.
Cheers, Tony

FollowupID: 381837

Reply By: NJ SWB - Sunday, Aug 28, 2005 at 11:18

Sunday, Aug 28, 2005 at 11:18

Farnell has some UHF handheld packs at the moment; check out p7 of this catalogue (about 1M download) http://au.farnell.com/images/en_AU/pdf/AU_S27_part1.pdf

I've previously looked up the Oricom twin pack ($117 +GST) and they were listed as 1W each. I can't find tech info on them today...

Cheers,

Scott

AnswerID: 127166