Re: remote antenna for DCF77 clock

Hello Michael,

 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.


Wow, you must yield a heck of a SNR out of that after they beefed up the transmitter. I can barely receive it here in the office (California). The clock only works on one wall and only in one particular spot. That is because there is aluminum foil backed insulation in the walls. It has to face a window and I have to make sure the screen isn't pushed over that window at night or it won't receive.

How did you get the wires through the pipe joints? How many turns could you squeeze in?

The only antenna like that I ever made was round. When I bent the copper pipe I pushed sand into it first so it would not flatten out too much. Then I found out the sand was too moist and didn't want to come out so I had to let it sit to dry for a week or so. That was before shop vacs became ubiquitous.

Regards, Joerg

http://www.analogconsultants.com
.

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