On Friday, 10 May 2019 19:41:44 UTC+1, tony sayer wrote:
In article , tony sayer
scribeth thus

Heres one I'd like to run past the leccy whizzes hereon for comment.

I have a need to twiddle a large FM radio aerial to three distant
transmitters that are 110 deg apart.

Managed to find a very nice aerial rotator on e-bay, brand new made by
RCA in America at a very reasonable price.



Thanks for all the replies! In no real order, the aerial concerned is a
FUBA UK Stereo 8 this is a bit of a beastie its an old design but its
been "renovated" It has a very narrow forward acceptance angle if it
were as simple as using a couple of aerials I'd have done that!. But
there is a situation where one Transmitter is only a 100 kHz away from
another so as best possible discrimination is needed.

I think we'll give up with the cap dropper idea, they did back in the
day go short which was fun not! for the series connected valves but
there do look to be much better plastic poly whatever around today.

Class X2 caps would get you better reliability in that respect. You'd probably need a bunch in parallel.

The problem using the Switch mode units is I believe the motors are AC
driven, there does not look to be any rectifier or switch mode built in

some ac motors are ok on dc, some aren't

to the unit furthermore the transformer looks a bit fiddley to rebuild

yep

and the extra wire needed for the UK mains may not fit so the idea of

it does. You use thinner wire.

using an existing tranny and tapping that at half way in autotransformer
mode seems OK and I do have a Toroid that would fit in there, but TNP's
reference to a simple 230 to 110 volts plug type reducer looks the job
so i think we'll go for that!

RS have one but its on flying leads and three times the price!

Cheers..

The only time a saleswoman made me laugh was when she told me they were cheaper than RS.


NT