UHF with poor reception

Submitted: Monday, Apr 29, 2002 at 00:00
ThreadID: 1049 Views:4399 Replies:5 FollowUps:0
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i have just installed a 3200 gme and dont seem to have great reception
i have a 6Db aerial about 700 mm long
on a axis base crome tube base about 300 mm long
is there a better setup that i could have ????????
i will be travelling mostly through the centre and want to be able to get in contact with other drivers ,for road conditions,camping spots and so on


look forward to your replies

.....
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Reply By: Chris Schulz - Monday, Apr 29, 2002 at 00:00

Monday, Apr 29, 2002 at 00:00
check all your connections especially the soldering job you did on the aerial lead. i have installed a 3400 with the same antenna and i get fantastic reception. also check your sql setting (see the manual)

c.
AnswerID: 3201

Reply By: Guy - Tuesday, Apr 30, 2002 at 00:00

Tuesday, Apr 30, 2002 at 00:00
Niko

The current mistake is to forget what the squelch is for on an UHF set?
If this is an automatic squelch may be the adjustement is not sensitive enough and
it will have to be re-adjusted by the techo at the manufacturer place.
The other common problem is the detuning of the antenna or non-tuned antenna.
To tune a UHF receiver you need an SWR meter for UHF (477Mhz).
A SWR meter for 27 MH will NOT do the job.
A standard UHF is not allowed to trnamsit more than 5 watts.
Usually with the best tuning of squelch, output RF coills, antenna and
antenna position and flat terrain expect 12 to 14 kms.
If you have direct and I mean direct line of site I can get 60 Km with
normal whip antenna.
In heavy rain forest and heavy canopy expect 1.5 to 2 kms.
If you want to get further contact use a 6 to 16 element Yagi antenna,
polarized vertically.
Guy
Guyr
AnswerID: 3221

Reply By: Eric - Wednesday, May 01, 2002 at 00:00

Wednesday, May 01, 2002 at 00:00
A couple of things to check
1. make sure you have a seperate power and earth lead all the way back to the battery, that way you wont have any voltage drop.
2. make sure the radio case is earthed to the chassis.
3. make sure the aerial base is earthed directly, not just via the coax.
4. You'll get MUCH better reception the higher you can mount your aerial. Ideally it should be on the roof.
5. dont have any sharp kinks in your coax.
Hope this helps.
Eric
AnswerID: 3251

Reply By: Fred - Friday, May 03, 2002 at 00:00

Friday, May 03, 2002 at 00:00
Nico - as a guide to whether your set is working well, expect about 30km in fairly flat country and if you're using a repeater 100+km is common. I spoke to a mobile near Mt Buller through a repeater while I was on the Hume highway. I knew his exact position (Mirimbah) and on my GPS he was over 80km away and the reception was perfect at 110kph. He faded at about 100km. Just to give you some idea of what to expect. Don't be too fussed about the antenna type. A mate up the bush uses a little wire one on the side of his car without a ground independent fitting (is that what the things between the antenna and base are called?) and it works as well as mine - I paid extra for that extra bit! He paid $15 for his!!! We've tried the sets from the same position and if anything he can trigger repeaters better than me! For contact with other drivers you would do just as well with a much simpler antenna I think - you certainly don't need anything "bigger and better" as the biggest restriction on UHF is that the waves travel in a straight line and therefore an enormously strong signal will simply go further into space!! I guess you understand that repeaters are usually in elevated positions and receive your signal and re transmit it thereby sort of "bending" it or giving it another straight leg over the horizon ....
AnswerID: 3317

Reply By: Fraser Coast Adventures - Saturday, May 04, 2002 at 00:00

Saturday, May 04, 2002 at 00:00
The tx3200 has three squelch settings, these can only be set by your dealer, of the three tx3200's in my company one was set at the highest squelch and two at the middle one, we had these changed to the lowest squelch and have much better reception of faint signals.
Your choice of aerial seems sound assuming that the connections are soldered properly, I too had this issue with a new aerial only to discover that i had damaged the end of the aerial lead pulling it thru the firewall. I chopped 10cm off the end amd resoldered and it was perfect. A continuity tester will tell you if you have damaged the coax.
Good luck, Dave
AnswerID: 3324

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