beginner installation of GME TX 3540

[jimc]

Hi all.

Finally getting around to installing my new GME Tx3540 and GME antenna into my D3.

I ordered it some months back but finally got time to install tonight...well I thought I was.

Before I made the final install, I thought I would connect it up and see if it worked with antenna coax terminated etc in the footwell before I placed it in final postion.

I terminated the coax cable checked continuity and confirmed all was OK..no short in coax. Connected power and started scan...the unit could not find any channels. Was on for 1 minute or so.

So I pull everything apart to recheck..and find the coax termination has shorted with a continuity test on the coax plug.

I reterminate and reconnect once confirmed no continuity...and radio rescan has same result. No channel can be found with any voices/music or other.

I can turn off squelch and get heaps of noise, but nothing else.

Have I busted the unit with the short? or is is because I have no idea how to drive the unit?..which is the truth.

any advice would be greatly appreciated.

[tony66_au]

I doubt the unit has been damaged unless you tried transmitting a lot with the dead short but usually the units get a bit quieter with blown output trannies.

You may just be in a dead zone as UHF is a line of sight medium.

The quiet may also be due to CTCSS (Selcall) being enabled but as im not familiar with the unit its a guess at best.

[tony66_au]

What sort of aerial, where is it mounted and do you have any pictures of the aerial installed?

[jimc]

sorry..should have mentioned the antenna is a GME AE4703 and is mounted to ARB bar. The disco 3 bar antenna mounts on the main bar next to the headlight assembly...so quite low.

the car was outside when I was testing..in a semi enclosed car port...but I would have thought I would have heard something at least?

Good to hear I have not fried the unit!

Would be great if GME had some hand hints in their manual for first time users/testers of their radio.

[tony66_au]

Looks like a half decent GID aerial, so long as you dont tighten them using brute force and get the plug termination correct it should all be fine.

PL259 plugs can be a bit of a bugger and you need to solder them quickly to keep the heat from soaking down the plug and melting the center wire insulation and you need to be fairly precise paring back the outer sheath and folding the braid back over it for the eath component too.

Get the plug too hot and you get gremlins.

its been a long time since I did this for a living but when i last played with CB's the length of coax on the aerials was crucial as it was a tuned length so if my info is still valid (it should be) then chopping off spare or left over cable may also cause issues.

But UHF is line of sight so if you cant see it then you cant hear or talk to it as a rule of thumb so id be tuning to one of the repeaters depending on where in Melb you are but 1, 3 or 7 were always noisy and id go for a quick drive to somewhere open and elevated to see what you can hear.

I must say that the unit you have is a very high spec unit and probably a bit too techy for a first time user and that too may present some hiccups, I grabbed the PDF of the manual and its a fair old read.

Hope this helped,

Tony

[tony66_au]

BTW Channel 40 is the Truckies channel and good for a radio check, just sing out "Can anybody give me a radio check" and you will hopefully get a reply.

[tony66_au]

Here we go, this will give you a slightly better idea of range etc

Note the difference between the 3db and the 6db pattern.

http://www.gme.net.au/public/pdf/brochures/antennaslr.pdf

And this shows Plug installation.

http://www.gme.net.au/public/pdf/brochures/pl259_instructions.pdf