[Lf] LF: Insulators]

[Andre' Kesteloot]

Peter Dodd wrote:

> 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
>
> <g3ldo at zetnet.co.uk>