Re: New Sangean DT-400W

Michael <michael.setaazul@...>

Thanks for the update, Paul. I look forward to reading how it looks and performs.

Michael UK
Apropos : Things seem to have gone quiet on the ferrite front.
Any new or improved designs in process?

Michael UK

Indeed, have the flat ferrites now (100mm*3mm*20mm) but looking for a large
diameter plastic tube dia => 12" to about 20".
This follows directly from Steve's assertion that a large diameter is needed
following his experimental evidence posted in this group.

Will place ferrites on each end and wind the contra-winding as per the
Polydorroff patents and will be the ~ 1/4" off ferrite surface.
This is the kind of plastic form I am

a grounded cage variable capacitor will be used to resonant.
pickup will be via a ~ 24" ferrite rod ( 3 * 8"by 1/2" dia 61 material Amidon0
this will have a contra-winding upon its surface (distance of wire to ferrite
surface ~ 1/4")
The idea is that placing this rod in the centre the mutual coupling will be such
that it is weak and therefore will not upset the Q of the main tuning circuit
yet enough signal for a sensitive radio.

all I have for now Michael
best wishes
Paul in the Northern Colony

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