UHF Qustion/ Help
Submitted: Monday, Mar 14, 2011 at 14:00
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Whitewulf
I have a GME TX3100 UHF, and have installed it in a new patrol but I can not seem to get long range (over 80m+). Tested in convoy is no issues I can send/receive.
It was installed in my
old car which is now sold and worked like a charm.
So far I have checked the connections twice, (tested un-soldered and soldered)
Purchased a new cable and antenna (6db), but still can only get very short range.
I don't think its the UHF as it will transmit.. but
Has anyone else came across this or offer another idea to try.
Thanks
Reply By: Bravo Man - Monday, Mar 14, 2011 at 15:59
Monday, Mar 14, 2011 at 15:59
I fitted a second hand GME to my 4wd and had similar trouble,would only transmit about 1 km but receive at much greater distance.
Took it to a techy and he tested it and said the amplifier was gone.Said this can happen if the unit is used without the arial connected.He tested the arial but it was OK.I think it cost me about $170 to fix.Its been fine since I got it back.....I think most
places will
test it for you at no cost
Thats what you get for buying second hand,I should learn
AnswerID:
448196
Follow Up By: Whitewulf - Monday, Mar 14, 2011 at 20:34
Monday, Mar 14, 2011 at 20:34
Thanks for the reply, with all my un-plugging and mucking around I am not sure if I may have done that too. Might just go buy a new one.
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Reply By: Member - Bruce C (NSW) - Monday, Mar 14, 2011 at 17:45
Monday, Mar 14, 2011 at 17:45
Hi Whitewulf,
To those of you that don't know,
You should never press the talk button on your sets when the aerial is not connected and the unit is powered.
This will blow the output transistors and you can receive but not transmit in such cases.
This may or may not be the case, to some extent, here.
If you have a mate with a working setup try connection it to his set up and see how you go.
Maybe first try your earth terminals at the aerial base and at the set.
UHF radios are ground independent but all the same I would
check the earths.
Hope this is of some help,
Bruce.
| At home and at ease on a track that I know not and
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Follow Up By: Member - Bruce C (NSW) - Monday, Mar 14, 2011 at 17:49
Monday, Mar 14, 2011 at 17:49
Meant to say
"UHF aerials are ground independent but all the same I would
check the earths.
| At home and at ease on a track that I know not and
restless and lost on a track that I know. HL.Lifetime Member
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Follow Up By: Mike DiD - Tuesday, Mar 15, 2011 at 20:15
Tuesday, Mar 15, 2011 at 20:15
UHF antenna can be Ground Independant or Ground Dependant - I have both types.
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Follow Up By: Member - Bruce C (NSW) - Wednesday, Mar 16, 2011 at 11:00
Wednesday, Mar 16, 2011 at 11:00
Thanks Mike, I was not aware of that.
Bruce.
| At home and at ease on a track that I know not and
restless and lost on a track that I know. HL.Lifetime Member
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Reply By: Member - John and Val - Monday, Mar 14, 2011 at 20:22
Monday, Mar 14, 2011 at 20:22
Is it a transmit problem or a receive problem or both? (Can you only be heard over a short distance, or only hear others who are close?)
If both transmit and receive are weak, it points to the aerial, cable or aerial connections (are you using the correct type of coax cable - 70 ohms or 50 ohms?)
If transmit is weak, but receive is ok it could also be an aerial problem, and this may have killed the transmitter output transistors.
If receive is weak I'd expect transmit to also be weak, and I'd look very carefully at your aerial and leadin. Suggest disconnect the leadin from the radio and
check there's no short circuit between the coaxial conductors, and no open circuit along the centre conductor.
I'd also
check that the radio has a good power earth connection to the body of the vehicle.
HTH
John | J and V
"Not everything that can be counted counts, and not everything that counts can be counted."
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Follow Up By: Whitewulf - Monday, Mar 14, 2011 at 20:44
Monday, Mar 14, 2011 at 20:44
Hi
John and Val
Good info
Will need to
check cable, but sure its ok as it came with the aerial, but who knows what happened in the
shop.
Thanks to all replies has helped point me in some direction.
Will
check cable and earth, if ok try to
test uhf in another car.
Worst case buy new.
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720563
Reply By: olcoolone - Tuesday, Mar 15, 2011 at 10:57
Tuesday, Mar 15, 2011 at 10:57
I would take it to someone who knows what they are doing and get them to
check it out.
It could only be 1 of 2 things, the radio or the antenna and both appear to be out of your league.
Spend the coin and get it right the first time , it might be money
well spent.
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