Subj : Antenna
To   : WAYNE CHIRNSIDE
From : Roy J. Tellason
Date : Fri Jul 08 2005 09:06 pm

WAYNE CHIRNSIDE wrote in a message to ROY J. TELLASON:

->  MR> "TOM WALKER" bravely wrote to "WAYNE CHIRNSIDE" (06 Jul 05 
->  MR> 07:06:00)  --- on the heady topic of "Re: Antenna"

->  WC>->  They why do Battery Radios work so well?

->  WC>Because they have a balanced antenna, you know those ferrite type
->  WC>things with the windings on them.


->  TW> We are talking about a VHF Weather Radio. you cannot use a Ferrite
->  TW> antenna at frequnecies that high.
->  TW> Actualy though the RF ground is really of most importance with
->  TW> Transmiters.

->  MR> IIRC before the advent of digital synthesized tuners in car radios,
->  MR> tuning was done using inductive coils into which a ferrite piston
->  MR> would be inserted or extracted, instead of the usual tuning
->  MR> capacitor. 

-> I've only ever seen that in car radios,  myself.

 WC> I've seen them, along with "vibrators" to step up voltage
 WC> for tubes.

Been a *long* time since I've seen any of those...

I remember both a construction article and ads selling commercial replacements 
for those.  Probably more trouble than I'd want to go through,  though.  I did 
some car radios for a while,  and it was a real PITA trying to deal with them, 
but the one time the guy came up with a pile of real old tube stuff I just had 
to pass on them,  wasn't worth what he was willing to pay.

 WC> OTOH my Cub Scout Crystal radio had an inductor wound on
 WC> a Quaker Oats box with a slider for tuning.

 WC> The capacitor was fixed and made from the genuine tin foil
 WC> once found on gum wrappers you could peel off the paper backing.

I don't buy gum,  don't they use that stuff any more?

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 * Origin: TANSTAAFL BBS 717-838-8539 (1:270/615)

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