UHF antenna
Submitted: Saturday, Jun 26, 2004 at 20:46
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Rowdy
I have a RFI antenna which has a cylinder at the base about 50mm x 25mm similar to the GME antenna A409L. It has zero resistance on the ohm meter when connected to the co ax cable, when I remove the antenna from the co ax the resistance is infinite. Another brand antenna I have has infinite resistance when it is fully connected. Does anyone know if this is normal for the RFI antenna.
Also does anyone know the measurement that the co ax needs to be peeled back to screw it into the base if the RFI antenna. I think it is 42mm but cant remember for sure. Maybe this is too much and is causing it to short circuit. Does the centre core of the co ax need to be stripped a couple of millimeters to insert up into the base. Any info would be appreciated.
Rowdy.
Reply By: Eric Experience. - Saturday, Jun 26, 2004 at 21:42
Saturday, Jun 26, 2004 at 21:42
Rowdy.
You have a falty base or antenna. The unit must be open cct with and without the anntenna connected. The inner must be stripped and soldered to the brass stud to make reliable contact, be carful not to transmitt without the antenna wired corectly or you will damage the radio. Eric.
AnswerID:
65265
Reply By: Phil G - Sunday, Jun 27, 2004 at 09:04
Sunday, Jun 27, 2004 at 09:04
I've had to fix a few of these out in the bush. The base rotates on the coax and breaks the wire. Very poor design. You can dismantle, solder it up and carefully reassemble. Be careful that the base doesn't turn when screwing on the aerial.
I prefer the ground independant bases that take the aerial with a PL-259 -style screw thread as they are never a problem.
AnswerID:
65289
Reply By: Rowdy - Sunday, Jun 27, 2004 at 13:15
Sunday, Jun 27, 2004 at 13:15
This particular antenna doesnt have a soldered base, the co ax actually is stripped of the outer cover to expose the braided shield which is then turned back down over the outer covering. The center core is then inserted into the base and then the whole co ax is twisted up into the base with the braided shield earthing onto the base of the antenna with the centre core just protruding into the chamber in the base. Its the only antenna of this style I have seen and is no longer made and I'm having trouble finding any info on them. When I changed it and another uhf over to another vehicle the radio died , thats why I believe that I probably got the length of the centre core wrong.
Rowdy
AnswerID:
65329
Follow Up By: Member - Bob L - Sunday, Jun 27, 2004 at 20:34
Sunday, Jun 27, 2004 at 20:34
Rowdy,
Just pulled a spare antenna (used) apart and measured 43mm
as you stated. This antenna is still available and I have one at work hopefully with spec sheet - if any different I'll let you know.
Cheers
Bob L
FollowupID:
326372
Reply By: Rowdy - Monday, Jun 28, 2004 at 17:33
Monday, Jun 28, 2004 at 17:33
Thanks Bob, I was hopeing to use the antenna but I think its rs. It's a bit more robust than the benelec I'm using now which has taken a hit on a tree branch and keeps separating at the join of the independant ground plain base.If I can't get the resistace right I'll scrap it.
Rowdy,
AnswerID:
65544