Re: remote antenna for DCF77 clock

Joerg wrote:
>
> Hello Michael,
> >
> > A pair of simple LC power inserters will carry the power to the
> > preamp capacitively couple the RF at both ends, and use large chokes
> > with their SRF well below the RF signal to couple the DC at each end. ...
>
> That is the really elegant way but at this low frequency you need rather
> large chokes that must not saturate at the DC current the pre-amp draws.
> In Bernhard's case a few feet of extra wire might be easier. Unless it's
> visible, then I'd go for your version with DC over coax. In the US we
> can run cables through the hollow ceilings or through attic. In Europe
> that is much more of a challenge since the usual ceiling is concrete.
>
> Regards, Joerg
>
> http://www.analogconsultants.com


I built my antenna before NIST upped the transmitter power and built
the new antennas at WWVB so it was designed to be mounted on a side arm
on a 40 foot TV tower. It is a three foot square, 3/4" copper pipe
Faraday shielded antenna that I wound the wire inside the pipe after all
the joints were soldered. I used a polystyrene cap and a small trimmer
to tune it. It still has the prototype preamp in it, I never did get
around to laying out and ordering a PC board for it. I had a bag full
of chokes made for low frequency tone detectors for old tube type pager
radios and they were perfect for the job. The pre-amp uses less than 50
mA, so there was no problem with saturation.

--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida
.

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