Sta-lok terminal Insulators

djc

djc

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Hi , I have two Sta-lok terminal Insulators fitted to the starboard rear backstay. Photo attached .
I am due to renew my standing rigging in the spring and was wondering whether its worth re fitting them on the new back stay ? .
I believe they are used to make the back stay into a HF - VHF ? aerial ? not 100% sure on this , Just wondered what else they are used for . would this b/stay aerial be handy as a spare VHF aerial , or any good as tv or car radio aerial .

Any advise / comments / uses , welcome.
 
I'm not a Tels Tech, but I imagine a backstay antenna would be too long for VHF. As the frequency goes down, the length of antenna needed goes up. So almost certainly intended for HF / SSB.

Someone I sailed with said that the length of his had been specially selected to enable him to pick up Radio 4 long wave from as far away as possible :-)

Pete
 
You'll need them if you are going to use a single sideband tranciever (SSB). If not, take them off and sell them: they are quite expensive. If you refit them you will have to buy new cones to suit your rigging wire, but they're not expensive.

You probably have a sintered copper grouning plate on the bottom of your hull to ground the antenna too.
 
The insulators are for an SSB installatin so not much use to you if you don't have an MF/HF radio. You can reuse the insulators (have them checked by a rigger) in case you ever need MF/HF.
 
Likely the wire will work as a VHF aerial - whilst you can nget aeruials that are too short, and aerials that are a wrong multiple of the signal wavelength, you cant get aerials that are too long. But if you do use the backstay for transmission dont forget that the other half of the aerial is the sea and you need some sort of dynaplate to connect to it.

Incidentally those insulators are quite pricey (£00s) and re-useable. If you ever re-rig the boat and dont want the insulators, keep them and flog them on ebay. Or pm me.
 
Thanks for the replys regarding my sta-lok insulators and back stay aerial . No SSB fitted on board ,sounds as if the back stay aerial could be used for Radio 4 possibly . Yes there is a copper ground plate fitted to the bottom of the hull although nothing attached to it .

I guess it would be an idea to have these insulators checked and refitted as they seem expensive . Are there any other uses for a insulated back aerial appart from SSB radio and possibly Radio 4.

Thanks again.

David.
 
Thanks Vic , thats helped a lot . I now realize the back stay would have to be cut twice in order to introduce the two sta-lok insulators plus 4 wedges which must weaken the stay and create more to pull out or go wrong , as i have no intention at this point to fit or use SSB , i will leave them off for now , and if i should ever go down the SSB route , i will have the insulators to refit in to the back stay.

Nice One , Thanks.
 
>and aerials that are a wrong multiple of the signal wavelength, you cant get aerials that are too long.

Aerials should be half the average wave length of the radio's frequencies. Typically that's around 34 feet. That makes it easier for the Automatic Tuner Unit to kid the radio that it's on the right frequency.

As you said the ground/sea makes up the other half of the aerial. The best signals are when the there is a very large ground - a steel boat or (in 42 foot Cat we saw) copper foil glassed in the both hulls the full length of the boat. In a GRP boat link as many bits of earthed metal together as you can.

> must weaken the stay and create more to pull out or go wrong

No, Staloks are much more reliable than swaged fittings. Many swage fittings have failed but I've never heard of a Stalok failing.
 
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