SSB Insulators

[BigAl.NZ]

I noticed the other day every other boat in the marina with a SSB has a top and bottom insulator.

Now while my SSB I think performs OK, I was surprised to see we don't have a top insulator, nor do I think there is any other form of insulation.

I left under the impression that:

1. It probably works OK
2. All my running rigging may be live when I transmit?
3. I assume the tuner can compensate with its magic for what it probably sees as an unusual length antenna

I have contacted stations 1200NM away OK at times.

Thoughts? (Radio is a M700 Pro)

[nuku34]

To the OP:
I've never seen a backstay SSB antenna with only a lower insulator.

I'm not an expert, but I would expect that:
1) All your standing rigging (not running rigging unless its wire) is carrying some current when you transmit because the backstay is connected to your masthead crane then to the (I'm assuming) alloy mast and hence to all standing rigging attached to the mast.

2) Depending on your hull material and how the mast and chainplates are connected to the hull, and general electrical setup, this current could cause corrosion problems, but this is a very complex subject!
3) Sounds like your (automatic?) tuner is managing to couple the SSB to the antenna ok, so from that point of view "if it ain't broke, don't fix it".
Looking forward to hearing from more knowledgable commentors...

[Jammer]

Some people use that arrangement by choice (Jim Cate being a notable proponent).


There are two disadvantages. First, yes, the entire rig is energized, and someone could be injured from contact with any part of it while transmitting, including exposed portions of the rigging below decks such as the mast and chainplates (on some boats).


The second problem is that there are likely to be specific frequencies where performance is poor due to the complex electrical shape of the antenna. Whether or not that poses a practical problem is mainly a matter of luck.

[Brian.D]

What kind of antenna are you using? Is it a bare backstay like on any sailboat or is your antenna insulated? It is possible that the connection at the top of the mast is insulated and therefore, no insulator is not needed. Or, there might be some other reason you do not have an insulator. It is also possible that your rigging is not being directly energized.

If you did not do the install yourself, then you might want to do a little investigating.