Re: Tesla Receiver Coil ..........success?

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Ed Phillips <evp@xxxxxxxxxxx>

"Thanks for the detailed description of your beacon, that's exactly 
what I was looking for.  I'm planning to build a Part 15 compliant 
beacon myself and am wondering if you could share the circuit diagram 
and parts layout. In addition to a Part 15 radio beacon I also plan 
to build a Part 15 compliant Tesla coil transmitter that uses a 
nearly identical driver circuit.  Both transmitters will be designed 
to operate on the precisely the same frequency, around 165 kHz.  The 
radio antenna is to be a 49-foot tall vertical (including tophat 
radius) with an 8-foot high counterpoise, as large in diameter as 
possible (on the order of 150 feet).  The loading coil is to have an 
aspect ratio of about 1:1 and be wound with AWG 22.  A variometer 
will be used for tuning.  AWG 22 will also be used for the TC 
transmitter secondary."

> I like that counterpoise!  Where can you find the space for 
> it?  I'll try to dig out the schematic.  If that fails I'll trace 
> the circuit by hand but I'm pretty lazy so that will take a while.
>
> > The transmitter is solid state . . . Uses a crystal oscillator at 
> > 32 x the output frequency, a CD4024 divide by 32 circuit, a CD4007 
> > buffer amplifier driving four Siliconix VN66AF "power" fets.
>
> "Am I correct in understanding that the four VN66AFs are connected 
> in parallel?"
>
>      Yes they are [with ferrite beads on drain and gate to suppress 
> VJF oscillations) but there are a lot better FET's to use now; 
> remember this was over 25 years ago.
>
> >    "Not sure if I answered all of your questions, and probably 
> > none to your satisfaction. . . .On the contrary, your insights are tremendous."
>
>
>  I just dug out of my files all but the first two pages of a 22 
> page set of notes I put together when we were putting out those 
> kits and trying to get guys on the air; includes schematics and 
> suggested coil winding details.  Too much stuff to scan but I could 
> probably copy it for you sometime and send the package to 
> you.  Give me your mailing address and I'll try to work up the 
> ambition.  All I have to do is remember how to make two-sided 
> copies as I'm too cheap to pay postage on 20 pages when 10 can hold 
> all the dope.  By the way, this was so long ago that you could get 
> new crystals in FT-243 holders from Jan Crystals for only $1.50 each!

Ed