[ARC5] Radio Altimeter

[J. Forster]

The APN-1 (and Navy version) certainly is a clever design, and there were
many, many thousands built. They used to be in little demand, but recently
have gotten hot. The antennas, little dipoles, are much sought after. It
seems to be related to TBM Avenger collectors.

It had several Test Sets, including the TS-16/APN-1. I have one and would
dearly like to find the manual. Anybody got one?

-John

=========



>    The APN-1 always impressed me.
> It is a very cleaver and simple radio altimeter using a wobbulator.
> Now, some old times know what that is. I once had a  graduate student
> from
> Poland come  to my office and
> ask  for a wobbulator and the technical staff looked at him as if he was
> nuts, I said sure we have one
> you may borrow. It was in the Polish to English dictionary he had. He
> borrowed it for a few days and
> returned it.
>     It had a Continuous FM  transmitter and a simple vacuum tube balanced
> mixer with an antenna
> for each. The FM signal was sent to the ground and when the reflected
> signal returned it was
> mixed with the output from the transmitter, by this time it would be at a
> slightly different frequency.
> And this audio signal was amplified and its frequency measured with a
> simple analog frequency
> meter. The difference frequency was proportional to the altitude.
>    Later they went to pulsed systems. But as kid I was impressed by this
> simple but very
> effective system.
> 73
> Bill wa4lav
>
> ______________________________________________________________
> ARC5 mailing list
> Home: http://mailman.qth.net/mailman/listinfo/arc5
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:ARC5 at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>
>