[Premium-Rx] Wellbrook excellence !

[Carcia, Francis A HS]

I was thinking or a similar problem with open wire feeders to a wire
antenna. It is a pain to readjust a tuner so wanted to make a broadband
interface to the radio. There could be some high voltages on the feed
line so I was thinking about doing a dual triode like a 12AX7 making a
dual cathode follower into a broadband transformer. A loop is a low
voltage device so I bet a FET or a pair of source follower FETs at each
end driving a BB transformer. Heck you could do a pair of gain stages
with a BB output transformer driving coax. I would think a FET gate
wouldn't be effected by the antenna reactance. The resistive load at the
gates could be pretty high like 1 meg so the signal wouldn't be
attenuated. OP amps would work but may not be quiet enough at low gain
settings?? frank

-----Original Message-----
From: premium-rx-bounces at ml.skirrow.org
[mailto:premium-rx-bounces at ml.skirrow.org] On Behalf Of Al Klase
Sent: Wednesday, November 22, 2006 12:32 PM
To: Alberto di Bene; premium-rx at ml.skirrow.org
Subject: Re: [Premium-Rx] Wellbrook excellence !

Alberto and the Group,

I too am an antenna experimenter, and one time manufacturer.  I don't at

all blame Well brook for protecting their intellectual property, I 
potted the magic bits of the antenna I sold years ago.  Anyway, to make 
a loop work without tuning it to a specific incoming signal, you 
probably need a "tranimpedance" amplifier that converts the current in 
the loop to voltage on the output.  Such a device will have a very low 
input impedance, like for instance, the summing junction (- input) of an

op amp.  See:  http://www.vlf.it/lowfloop/lowfloop.htm  Problem is, it's

difficult to get this working above MF.  I don't think the Dallas 
Langford circuit is applicable here.  If anybody has any ideas, let's 
hear them.  Loop antennas have a lot to offer, especially if we don't 
have to retune when we change frequency.

Regards,
Al

Ken chattenton wrote:

>HI Alberto, all from Ken in the UK,
>
>The number of times I have heard similar comments to yours Alberto
regards 
>duplicating the amp.
>I know it would be nice to do, but I'm afraid there's no chance really.
>Guy protects this little unit by 'potting' it in compound ( plastic
conduit 
>box ) and he will not release the circuit dia to anyone, and why should
he 
>after all the research and work he has expanded in it's design.
>I have never heard anyone complain about the products and support
offered by 
>Guy. A truly professional in every way.
>
>
>  
>
>> I know that I am asking almost the impossible. 
>>    
>>
>
>
>_______________________________________________
>
>
>
>
>  
>

-- 
Al Klase - N3FRQ
Flemington, NJ
http://www.skywaves.ar88.net/



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