[AMPS] Plate Choke

[km1h @ juno.com]

On Fri, 12 Dec 1997 08:25:13 -0600 w5hvv@aeneas.net (Roderick M.
Fitz-Randolph) writes:
>This is not exactly along the lines of this reflector but I
>know the expertise is certainly here, hence the following:
>
>I am in hopes that someone here can offer me some direction on
>how to wind a plate choke (gauge wire, no. of turns, diameter
>of wood dowel)  for a tube that will pull about 200 ma. at less
>than 1200 volts.  The choke needs to be suitable for 160/80/40
>meters.  I don't anticipate using it at any higher frequency.
>
>It is for a Hartley and frequency stability is of paramount
>importance.  Any suggestions will be gratefully accepted.
>
>Thank you,
>
>Rod, N5HV
>w5hvv@aeneas.net

The ARRL handbook has covered this for ages Rod. However at 160M I doubt
that you have the equipment to turn out a 1mH or larger RFC. RF to PS
isolation is a lot more critical in that Hartley and a garden variety
200uH RFC will be insufficient.

Time to look for an old National, Millen, JW Miller or similar pi wound
choke. JW Miller # 4533, 4534, 4535 would all fit the requirement. 

B&W once built a QRO choke wound around ferrite that was based on a HRM
article. Perhaps a reader can offer insights into the use of ferrites in
high voltage high current applications. 

73   Carl   KM1H 

--
FAQ on WWW:               http://www.contesting.com/ampfaq.html
Submissions:              amps@contesting.com
Administrative requests:  amps-REQUEST@contesting.com
Problems:                 owner-amps@contesting.com
Search:                   http://www.contesting.com/km9p/search.htm