ANTENNA

[doctor]

HI GUYS;
I noticed in connecting my antenna to the swr tuner I noticed when attaching the pl259 to the connector the signals are very low and in fact do not pickup some of the signals the other antenna does. In backing out the antenna and just leaving in the center conductor signals loud/clear...that is with the outside of the pl259 not screwed in....This tells me that some where in the antenna it is grounded am I on the right path of the trouble?

DOCTOR

 

[The DB]

That is a definite maybe.

Need more information, not the least of which is what kind of antenna is it...

Just because an antenna is grounded might not be a bad thing, some antennas are designed to be grounded, others not, and others still can be used either way...

At first glance the two halves of the antenna seem shorted...

I don't have enough information to say much beyond that...


The DB

 

[Captain Kilowatt]

Either a short or an open in the coax cable. With the shield not connected the inner conductor of the coax is acting like an antenna itself accounting for the increase in signal. When you connect the shield you prevent that conductor from picking up signals.

 

[W5LZ]

Just because you hear more when the 'ground' is removed (unscrew the connector) doesn't necessarily mean there's a problem with your antenna. There certainly can be, but what you are hearing is fairly 'normal', happens with all antennas. As C.K. said it means that all of the cable to the antenna, AND the antenna are acting as the thingy that's 'grabbing' signals', not just the antenna by it's self. An antenna is usually resonant on some particular frequency, which means that it isn't 'listening' as 'hard' to other frequencies. When you disconnect 'half' of the antenna it means that it's listening to whatever signals happen to be present and 'hitting' the antenna. That's NOT a good way of describing it, but it get's you 'close' to what's happening, sort of.
Just don't forget to reconnect that connector before transmitting!
- 'Doc

 

[doctor]

FINAL...
I built another 80 meter antenna today<actually 75 meters>, and disconnected the other antenna and put up the dipole, work yes, swr with tuner 1 to 1. The other antenna<the problem>, is down , believe the problem was in the center connector, where water could have gotten into the center and after many years corroded the inner section, not sure but the problem has been solved this day.

DOCTOR