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LF: Insulators

To: [email protected]
Subject: LF: Insulators
From: "Peter Dodd" <[email protected]>
Date: Sun, 10 Dec 2000 18:45:13 GMT
Reply-to: [email protected]
Sender: <[email protected]>
Laurie said:
I dont know how to calculate the voltage at the end of a top loading =
wire,but I use two ribbed ceramic insulators with a peice of terelene =
rope (5mm) between.The rope has burnt through!!!

Ceramic insulators should not be a problem. However my Admiralty Handbook of Wireless Telegraphy (1925) has this to say:
"Loss by Leakage over Insulators
..........................It is, therefore, the duty of the wireless staff to keep these (insulators) scrupulously clean, especially after high speed steaming, heavy rain or bad weather, since under these conditions the insulators will probably be covered with a semi-conducting layer of 'stokers dirt' and dried salt".

I don't know about 'high speed steaming' but the lake around my shack is now large enough for me to sign Maritime Mobile.

I find that ribbed insulators are worse for collecting dirt, which gets down in between the ridges. The long PA0SE ceramic insulators are best although the tooth brush handles should be OK. I think that a method of lowering the antenna for maintenance is a necessary design feature, especially in coastal areas.

--
Regards, Peter, G3LDO

<[email protected]>






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