Outer Limits 4x4 Board

OK,

i know how to do it:

-strip the outer black insulation off
-peel back the silver sheilding
-strip the inner white cable insulation
- twist the inner cable, join cable and solder it.
-then put the shielding back over and tape up.

Once this is done i have found that my UHF range is farked....

i seem to be able to transmit maybe 2kms but i can only recieve about 1km

and this is in a good quality Uniden UHF hard wired unit and a top notch uhf areal......

do i need to get is swarred in or is there another problem with the soldering technqiue???

i used to get better range with this system......

screwy

Don't strip the insulation back so far - you should have just enough to connect the sheath to the 'ground' and solder in the centre wire. If the wire is old, it could be perforated and have internal water corrosion - totally kills antenna cables. If you have knotted the cable up (if you can see 'twists in the cable' from the outside, you have probably damaged the conductor - new cable time.

Both the radio and antenna are well earthed? Bad ground connection = bad performance. Make sure what you earth it to IS earthed (I had to put an earth wire from my bull bar to the chassis to ensure a good connection).

Scrapper wrote:Don't strip the insulation back so far - you should have just enough to connect the sheath to the 'ground' and solder in the centre wire. If the wire is old, it could be perforated and have internal water corrosion - totally kills antenna cables. If you have knotted the cable up (if you can see 'twists in the cable' from the outside, you have probably damaged the conductor - new cable time.

Both the radio and antenna are well earthed? Bad ground connection = bad performance. Make sure what you earth it to IS earthed (I had to put an earth wire from my bull bar to the chassis to ensure a good connection).

i only strip it back far enough to get at the wire and re shield it over.
i believe im doing it correctly.....

but the earth thing is interesting.... i may look into that.

screwy

are you trying to join the cable or putting new cable in

MUD80D wrote:are you trying to join the cable or putting new cable in

join it, but i already have... i know how.

im just saying that i have little to NO range.....

screwy

re-run new cable and see what you get uhf and am dont like cable being joined

Joining cable, for antennas, is bad. Period. You get 'moisture leaks', even if you heat shrink over it (I'm sure you don't use the moisture excluding gels!) and tape is almost as good as not using anything. Moisture from the air (or immersion!) will get into the cable and change its dielectric constant, that in turn changes the cable characteristics. Also even if you are a pro at joining cable, you still get tiny imperfections that can be detected with a Time Domain Reflectometer, that do impede performance.

I agree, it shouldn't STOP it running (though it may run poorly), but the cost of cable versus the hassle, use a new piece and check your earths.

OK, time for a silly question.

You did insulate the inner core from the shield where the two are joined? It's just that you don't mention it.

If the shield is shorted to the inner core at the join...

I hope it was a silly question.

Scott

Assuming its not got a low resistance short High frequency cables cant be sucessfully joined as you get what is called "reflection: at the joint. Caused by impedance mismatch from memory.

Better to replace whole cable or buy correct joiners and plug together,

Bazzle

gday screwy! im in ingleburn and am a uhf enthusiast aswell as 27meg, if you havnt sorted your problem out yet or perhaps would like me to sight your setup and give you any tips feel free to contact me on 0408 288 565 thanks HARV

As has been said, don't ever try joining coax by soldering two pieces together! It will only result in problems sooner or later.

Buy some new cable (make sure it's the right spec) and see how that goes.

another vote for install new cable. your SWR and impedance will be screwed if you try and join a UHF antenna cable. it work sort of ok for AM, but not for UHF - even one mm of exposed core in a UHF cable is bad juju.