antennae

[mireland]

I have 2 antennae on an isolated backstay. One is a narrow cylinder clipped to the stay with jubilee clips. It seems to be an impedance of some sort. The other is a small square metal plate clamped to the stay by means of a backing plate. They are mounted close together a few feet up the stay from the deck.

What are they? Any ideas?

If you know the answer it's easy!!!

<hr width=100% size=1>

 

[Guest]

Post deleted by danfoley

 

[mireland]

I had wondered about that but I have no SSB radio! Could it be anything related to the GPS?

<hr width=100% size=1>

 

[Bergman]

Sounds very odd

Suspect the objects in question are nothing to do with being an aerial

The cylinder could be some sort of stub used for matching the aerial but I would'nt expect it to be clamped on with jubilee clips, it just becomes part of the aerial then. In any case using a matvhing stub would be an unusual thing to do - although it would work, at least on a limited range of frequencies.

Perhaps you could give us a more detailed description at the moment I'm doing heavy duty head scratching on this.

As for Fatipa:

A balun is a device to connect a balanced load to an unbalanced source (or vice versa) Typically it uses a ferrite ring with 2 windings. It can also act as a transformer with 2:1, 4:1 or 6:1 ratio.

An aerial on a boat will almost invariably be unbalanced, certainly a backstay or a whip antenna is unbalanced. Transmitter and receiver inputs are also unbalanced. There is no need to use a balun between receiver and aerial, in fact one should not do so. A tuning unit is what you need both for receive and transmit.

An aerial is an aerial

To the best of my knowledge there is no such animal as a "balun aerial" Not sure what it is you have there or indeed why it should improve reception but would be interested in a description and more detail.


<hr width=100% size=1>

 

[Oldhand]

A rat catcher? Give us a picture please.

<hr width=100% size=1>

 

[Graham_Wright]

It's a bird feeder.

<hr width=100% size=1>GBW

 

[tugboat]

Wondered if the square plate might have been a mount for one of those old octahedral radar reflectors?

<hr width=100% size=1>