UHF aerial tip replacement not working

Skip to the last sentence if you do not have a good clean and small soldering iron. And the "reliable and clean environment" skills to use it. And my advice.

That "bit of solder" was connecting the antenna cable (coax) that enters the bottom of the whole antenna to the "active" section of the antenna (the tip). When you undid the screw you broke the connection inside the "silver" 1 inch long bit. The cable has to be extracted from the antenna and stripped back and tinned and the braid prepared for a new fitting. Then all solder and left over wire has to be removed from the short section. You then screw it back on the antenna "base" and feed the prepared wire up the center of the base so that the tinned end sticks out the top. Depending on the design of the base the braid has also got to be folded back and connected to the base. Then the wire is soldered to the 1" bit and the rest of the natenna put back on.

I may have missed something there as it's years since I have done it.

The easy and best way: Get the communications mob to do it.

In 30 years of using UHF equipment, I've never seen a fibreglass aerial break, except when colliding with a gidgea tree, at speed. Those are serious vibrations on your bull bar, mate!

Seriously, if the fibreglass has broken, I'd be a bit concerned about the soldered joint, underneath, where the co-ax is soldered on. It may have fatigued, and broken, causing your apparent loss of signal.

Don't know if Katherine has any techs in town, but there should be some in Darwin. May only need the aerial to be dismantled and re-soldered.

Bob.

Sounds like the same base as my UHF antenna - if so, the design is more complex than it appears at first glance - some rings on the body insulate parts from others etc. -you'll may find that the inner wire in the coax cable was soldered into the item that you screwed off. Once a new part is just screwed on, you run the risk of cooking* the radio with shorted coax wires. I suggest dis-assembly of the whole antenna body - study the design and once understood, carefully reassemble, with the coax installed as required. Following that, the integrity of the coax's inner and outer circuits have to be checked with a test light or meter to make sure there are no shorts (vital). From you description, there is a fair chance that after fixing the antenna you may find that the radio is cooked* (transmitting with no proper antenna circuit for the energy to go to - here's hoping its ok but).
*bush radio tinkerers' term for "a thingamy inside the radio is probably buggered".

I forgot this bit.

Do not use the radio until it is fixed. You may blow the finals. Unlikely but expensive. In bush terms. It may blow a poofer valve.

Okay!!!!

Quote - "Even though the replacement antenna tip screwed on nicely my concern is that there is no contact internally between the remaining solder tip on the internal thread and the inside of the new aerial. Is this correct? Should I be able to simply screw on a replacement as I have done and have it work?"

Yes it should work OK. The male thread at the top of the base is the sole electrical connection to the whip. It sounds like you have a problem with the lower assembly. The lower piece that is left when you screw the upper whip piece off is half of a co-axial dipole. The male screw thread at the top is connected to the inner wire on the co-ax cable. The outer braid of the co-ax is connected to the metal outer sleeve (which forms the lower half of the dipole.)

Checking the lower section is very simple. You will have to extend one lead of your meter with a bit of extra wire. Disconnect the plug from back or your transceiver. Set the meter to its lowest ohms range. Check the continuity between the male thread on the base and the pin of the plug. Then check the continuity between the metal sleeve on the base and the body of the plug. The reading on both of of these tests should be zero ohms or very close to that. Then set your meter to its highest ohms range and check between the pin and the body of the plug. It should be open circuit.

If you don't get the results described above, you have a fault in the base (in your case you will know where the fault is.) You can have a shot at repairing it as described above. If that fails then you will need a new base. If you are still within range of the supplier of the whip he may agree to refund you for that and supply a whole new antenna.

Why do you need the UHF Aerial on the Bull Bar?

I was advised by a Communications Retailer in Adelaide that a "mudguard" mounted stainless steel arial is as good for reception as a "wanker pole" on the bullbar.
They sell all types to cater for all customer requirements.

Mine is 900mm in length and vibrates a fair bit I have never had a problem.

I had a similar aerial on the Jackaroo and also have one on my Colorado.

The main thing as I was advised, is that the top of the aerial should be higher than the roof and anything else mounted to it and reception will be as good as the big fibreglass poles mounted on a bullbar.

Another thing I like is the top of the aerial acts like a "gauge" for multi-story, or underground car parks. If the aerial is just touching the lowest obstructions then I know I have sufficient clearance:-)

Thanks for the advice everyone - my knowledge of UHF is limited so I will get it checked out in Darwin by a comms mob

OzNjB

Forget those wanker aerials
get one of these

Click here

Nothing much worries them, and I can guarantee them not to be effected by corrugations

They just last !

Cheers
Bucky