[GreenKeys] Re: polar loops

[gil smith]

Hi Eugene:

With an adapter, you could convert a neutral-loop keyer to drive a polar 
loop.  Something like an H-bridge of transistors comes to mind.  Hafta play 
with it a bit.

The loop sense needs no change -- the zener will conduct in forward mode 
for the other polarity.

gil

At 01:53 PM 6/16/2004, Eugene Hertz wrote:
>Well, Jack (wa2hwj@)has become intimately familiar with the ticker, and I 
>believe his assessment was it could not be modified for neutral...
>
>If you want to see pix (Ticker 1 has good pictures of internals)...
>
>http://www.hertzmail.com/5a/
>
>Ultimately, I would love to find/build a circuit that could take rs232 and 
>key a polar loop +/- 60ma.  In that way I would use software to handle 
>ascii-6-level conversion and to signal the rs232 lines at the right baud rate.
>
>Any ideas?
>Eugene Hertz
>
>
>
> >-----Original Message-----
> >From: gil smith [mailto:gil at vauxelectronics.com]
> >Sent: Wednesday, June 16, 2004 04:57 PM
> >To: greenkeys at mailman.qth.net
> >Cc: 'Eugene Hertz'
> >Subject: polar loops
> >
> >Hi folks:
> >
> >Can anyone give a decent explanation of a polar loop? Eugene apparently
> >has a polar machine, and wants to drive it -- I presume there are other
> >polar machines out there as well, though we don't hear much about them.
> >
> >If I understand it correctly, a polar loop reverses the current direction
> >for mark/space, unlike the current-on/off of a normal loop. I presume
> >polar lines would support longer distances and do better under noisy
> >conditions.
> >
> >What is needed to convert a standard loop to drive a polar machine?
> >
> >Can Eugene's 5A machine get a simple wiring change to bypass the polar
> >input and drive the selector magnets directly from a normal loop?
> >
> >ps: Eugene: do you have any pics of your machine?
> >
> >thanks,
> >
> >gil
> >
> >
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> >; vaux electronics, inc. 480-354-5556
> >; www.vauxelectronics.com (fax: 480-354-5558)
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> >
>
>
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