UHF Problems

Post by **antt** » Wed Apr 30, 2003 9:49 am

i've got a uniden uh013 (the scanner and uhf in one unit thingo) UHF and it has problems transmitting. some times it will transmit perfectly fine, but most of the time it transmits static, which other uhf's can pick up, but like i said, it's just static :(

it recieves fine and i've picked up as far away as bribie island on the scanner

anyone know what could be the problem???

Post by **Lil Menace** » Wed Apr 30, 2003 9:57 am

i'd check your aerial just to make sure, the scanner will pick up a long way away because its just reciveing, its the peoples that your listening to with the big power output,But yeah just check your aerial.

Post by **moose** » Wed Apr 30, 2003 10:02 am

check your mike !!!!
try someone elses if possible !!!!

Post by **purefmx** » Wed Apr 30, 2003 10:18 am

Do you know the difference between simplex and duplex and how repeaters work?
I hope im not offending, but some people are new to this.

Post by **antt** » Wed Apr 30, 2003 10:56 am

purefmx, i know the basics about simplex and duplex operation, how could this be causing my problem

Post by **antt** » Wed Apr 30, 2003 10:58 am

btw, it picks up my mates uhf's fine, not just the scanner

Post by **moose** » Wed Apr 30, 2003 11:01 am

thats why I reckon MIKE problem !!!!!

you can hear them !!!
they cant hear you !!!

so , kinda rules out aerial !!!

Post by **BUNDERA** » Wed Apr 30, 2003 4:26 pm

i fixed a mate of mines uhf the other day. It would recieve fine but transmit static and i found it to be the ammount of power getting to the unit.

Check with a multimeter that u are getting a good 12.5Volts.

Moose's idea of the mike shoutn't be over looked.
Hope u fix it.
Nick

Post by **baby_troupe** » Wed Apr 30, 2003 7:22 pm

Also check the aerial.
If you do not have an independant groud type, this can affect transmission. Also if the aerial is lower than your ground plane (roof line) it can have problems.

Post by **landy_man** » Wed Apr 30, 2003 7:48 pm

baby_troupe wrote:Also check the aerial.
If you do not have an independant groud type, this can affect transmission. Also if the aerial is lower than your ground plane (roof line) it can have problems.

Sorry but that is incorrect.
A ground independant antenna does not work better than a ground dependant one.....
Your roof line in not your ground plane....

Ground independant (G.I.) antennas were desinged for mounting on non-metallic surfaces such as fiberglass canopies etc. and have been adopted by most users as they provide an easy mounting system i.e. you don't have to ensure that the antenna is grounded correctly and on a large metallic area e.g. your roof, from which it can radiate....the steel tube on the bottom of G.I. antennas acts as the ground plane... a very small one at that

The ground plane is the surface on which a ground dependant (G.D.) antenna is mounted on.....i.e. if you were to mount a G.D. antenna onto a bullbar, the bullbar becomes the ground plane... not an effective radiation surface.

Website · Post by **XXXL80** » Fri May 02, 2003 8:31 am

i agree on the mike prob. I had an older electrophone and the same thing kept happening to me, i got a new aerial and it still did not fix the problem, then one day i had the s***s and i unscrewed the mike only to find that a wire had actually come loose 40 bucks later and i was back in business.

Post by **DAZZ** » Fri May 02, 2003 9:53 am

I would swap the mic out with a known good unit. Uniden mics are usually trouble free but I have seen this problem with them.....

I use an independant ground base with a 6db gain antenna with my TX3200 and it has improved range heaps. Even using a short stainless antenna with the IG base is an improvment over using a std base. And both have a good ground......
PLS explain??????

Post by **landy_man** » Fri May 02, 2003 6:50 pm

if you are mounting the antenna on the bullbar... yes a ground independant antenna is better as the bullbar is a terrible ground plane.....

however, the roof of a vehicle is a far superior ground plane compared to the bullbar or the G.I. base.

Post by **mick!** » Sun May 04, 2003 6:36 pm

I have found a problem similar, but mine is only a problem sometimes.

I have been told, that I should try an independant ground, aerial.

They are the best apparently.

Good luck !

Mick

Post by **antt** » Thu Jan 08, 2004 1:22 pm

well, thought i'd update this thread seeing as i 'think' (fingers crossed) i've finally fixed the problem. for the past few months, i couldn't be stuffed trying to sort out the uhf, so i've just been using a little handheld uniden.

anyway, i tested it to make sure i had good power (12.89v), which it did, checked the ground on the antenna, had a good one. finally, as i was about to smash the sh*t out of it, i noticed that the aerial was moving, and it would cause the static each time it moved. when the car was dead still, it was fine, but as soon as there was some movement, it would start to play up.

so, pulled the base of the aerial apart, and there looked to be a couple of little bits of metal in there. so, blew them out, screwed it back up, and it seems (hopefully) perfectly fine now. hopefully it should keep on working now

anyway, thought i'd drag this back up, cause the mods might wanna move it to the auto elec section

Post by **landy_man** » Thu Jan 08, 2004 5:14 pm

bad earth is a common problem on antennas.. be it comms, tv, radio...etc. that is why most radio shops recommend G.I. antennas as any fool can wire them up...

Post by **jasonmcc** » Mon Jan 12, 2004 7:34 pm

Hi Guys

As an aircraft radio technician. I would be guessing you have an intermittent Microphone. Clean the plug maybe pull the plug apart and have a look for dry solder joints/broken wires. Or just buy a new mic they are pretty cheap. If its intermittent problem I probably wouldnt think its an antenna problem. Is it happen when your talking in the radios maximum range or does it happen when your really close sometimes.

Cheers

Jason

Post by **oozuk** » Mon Jan 12, 2004 8:58 pm

i had the exact same problem with my mic and i replaced it and it was all good if you don't believe us then go to OLBIS Communications and get them to plug another handset into it and you will see the difference !!

they also do repairs so they could test your old one as well as your unit and aerial..

Post by **antt** » Mon Jan 12, 2004 9:02 pm

oozuk wrote:i had the exact same problem with my mic and i replaced it and it was all good if you don't believe us then go to OLBIS Communications and get them to plug another handset into it and you will see the difference !!

they also do repairs so they could test your old one as well as your unit and aerial..

well, the problem isn't fixed!!!!!

went out to ormeau on sunday, worked for most of the day, but started to sh*t itself again in the arvo

00ZUK, where is this OLBIS communications place?????

Post by **zuker1500** » Sun Jan 25, 2004 10:32 pm

Sounds like antenna and cable problems to me.

From memory Olbis comms is on the service road on Ipswich road at Rocklea.http://www.olbis.com.au I would look at getting them to fit a GME Electrophone AE4018K1 antenna. This is what we used to fit to all the 4x4's in Mt Isa as they were extremly robust and the were Ground Independant and make sure that when they run the cable not to use the crappy cheap connector provided with the antenna. Get them to fit a UHF-21 connector. This is one of the most common faults in antenna installations but when you fit the uhf 21 connector it perfectly isolated the conductor from the ground. This should hoepfully solve your problem. Also, if you are on the northside and cant get to olbis go and see Mark from Kyle Communications http://www.kyle.com.au he is on Lutwhyche Road.

Lets hope this fixes it!!

Danny

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