Fitting A UHF

G'DAY MATE.DONT KNOW DISCO'S WELL BUT IN OUR CRUSIER PETROL WITH EVERYTHING ELECTRICAL WAS ADVISED BY ARB REP TO WIRE UHF INTO CIGARETTE WIRE (+) AND EARTH OFF BODY UNDER DASH NEAR CIGARETTE SOCKET,FIND THIS EASIER THAN RUNNING OFF BATTERY

Hi dolfin,

I got a couple of automotive type connectors from Dick Smiths and wired in both a permanent & an accessory circuit. That way I can change it over quickly & easilly if I want to. You just need to place the plugs somewhere where you can get at them without pulling the dash to pieces. Also, you can make up an adapter to run something else like a GPS later on if you want to. They all just plug in.

Cheers

Dolfn
The Cig Lighter Circuit in a Disco is only powered when motor running which would be a real pain. Suggest you run a decent dc line say minimum 4t from battery and make sure you use a 10 amp fuse at the battery. Normally if negative is off battery we fuse that as well otherwise choose a good ground point.
Look for an existing grommet in fire wall which will take both dc and antenna coax but DONT take wiring across firewall as it gets too hot especially for coax as Ive seen the internal insulation melt causing a direct short.
If you wish to switch off with accesory line try a relay activated from any accesory source ie radio, wiper motor?.
Current draw on rx only is pretty low and should not be a problem if accidently left on for a day or two.
Which Antenna did you choose and where do you plan to install it ?
Cheers Bob.

PS used to own a 91 Disco but converted to Nissan Patrol a few years back.

Hi dolfin,

I bought my TX3200 from ATRC in sydney (very good, only sells radios) and he told me to run it straight off the battery (no voltage drop as you want the maximum supply voltage to the radio). Also, your original wiring is left as is.
Originally I wanted it off the acc as I thought that it would be turned on most of the time but the novelty soon wore off and there are too many idiots on air in the city. mostly the radio is left off unless on a trip.
Being able to use the radio without the ignition on is a plus (anyone can use it or you may have lost your keys!).
I have accidently left the radio on for 3 days, no problem.
I ran a 2.5mm cable straight from the battery (both +ve and -ve) and use it to power any other accesories I add such as radio/gps/chargers etc.
You MUST fuse it at the battery terminal (I used a 10A fuse) and use rubber grommets thru the firewall.

JC

Hi Dolfn,
My sugestion for running electricals for yout new radio - DC power - use minimum 4mm "figure 8" auto cable. Something in a nice red/black or red/red-black trace colour is easiliy identifyable. For the connector at the radio end, shorten the supplied DC cable to around 10 to 12 inches. You will find that the factory DCplug- lead will only be 2 or 3mm square CSA cable (Cross sectional area) - bare minimum for the required current draw. Extend the power lead using the 4mm CSA all the way to the battery. Solder the joints at the radio end and insulate like your life counts on it. ( one car fire later it just might !!!) run the power cable where the original manufac. loom is. - This will be the most protected from heat/under bonnet nasties. At the battery, use only a quality fuse holder, weather proof and insulated. As stated earlier fuse the positive side of the cable as close to the battery terminal as possible. ( around 4 to 6 inches is practicable). Only use solder joints or very high quality crimps with proffesional crimping tool. Steer away from the earlier mentioned Connectors that "splice " the cable. These have a habit of cutting strands of the main conductor, and also loosing the outer plastic casing resulting in a short. The reason to pay particular attention to good joints and quality connectors is simple - reliabilty and functionality. The name of the game is minimise the voltage drop.- for every crimp/splice/push terminal, a small voltage drop ( due to resistance) will occur. Too many of these and the Transmitter will operate at far less than optimum perfermance. - just like "yellow headlights", voltage drop causes your radios out put to fall significantly with only very minor drop in operating voltage.

As for using accesory/ignition circuit for power - ever tried listening to Fox fm without the keys in the car ??? - only consideration here is remember to turn the thing off at night ( especially with only one Battery). - Whilst on a winter tour of duty of Antarctica, Stationed at Casey as an RF techo, I remeber One Balmy minus 17 degree night, a snow cat operator lost a very important key ( yes they had keys for the ignition, never know when one might get stolen!!!!) but still managed comms - why ? we always radio direct wired the radio. ( a hole nuther storey...) which is probably why I stress the high reliability, water proof, job - you may just find that ( and I pray you never do) have a situation that you need the damn thing to work!!!

As for coax - quality cable ( beldon rg58), connector, good stress relieving and water proofing, make sure you go through the fire wall using a solid grommet, ( I assume you are bull bar mounting antenna) use cable ties sparingly. Once again watch hot spots in engine bay, try to run the coax on opposite side of engine bay to exhaust manifold. Electrical interference usually doesnt enter the receiver from the coax cable itself so run this with the other cable will be fine. ( running the power cable direct will actually help if there is any interference, the Battery has a "capacative effect" and shorts out all ac ) Maybe we should worry about an interference problem if one arrises !!!


Thats about all i can think of at the moment, just my 20 cents worth any way. ( And 15 years in the trade!!!)

all the best with it,

Jarrod.
P.s. have you got an antenna ?? can give you my opinion if you are interested.

My radio is connected to the heavy green-white wire coming out of the lower RHS in the fuse box under the DS dash. It is a switched wire and runs into a loom not long after the fuse box. After the red radio wire is spliced into the green-white wire it has an inline fuse and runs to the radio. The earth I assume is just bolted down somewhere or connected to another earth. The aerial passes through the DS bung into the engine bay and to the bullbar. To make life easy pull the bung out, drill a hole or cut a nipple and pass the aerial lead through then put the bung back in. Solder the aerial plug to the wires. I actually have the TX3400, with the main unit residing under the dash.
Regards
Slunnie