User-agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:29.0) Gecko/20100101 Firefox/29.0 SeaMonkey/2.26.1
Hi Charles,
You have a high-power DC resonant charging reactor (or choke) most
likely from a fairly large stationary or marine radar system. Bendix was
a major manufacturer of radar equipment during, and after, the 2nd World
War. Resonant charging reactors are part of a "line-type modulators".
The charging reactor efficiently (re)charges the pulse forming network
(PFN - a combination of inductors and capacitors that was designed to
mimic a charged length of HV transmission line). The charged PFN is
discharged into the primary of a step-down pulse transformer, using a
spark gap or thyratron switch.
The PFN and pulse transformer create a relatively square-shaped
high-power pulse, typically several microseconds in duration, that
powers an RF power oscillator tube (a magnetron or klystron). The power
oscillator generates an approximately square-envelope pulse of microwave
energy that is piped and transmitted through a highly-directional
antenna to echo-locate distant objects.
For more information, Google "Pulse Forming Network" or "Line Type
Modulator". The high-current rating of your reactor would allow it to be
used with a relatively large storage capacitor in a DC coil. The choke
can handle a 0.1 uF tank capacitor, allowing you to handle ~25 kW of
power at maximum break rate of about 480 PPS. Very nice find!
Radar charging chokes appear to be relatively rare at Ham Fests or
Teslathons. Over the last 25 years, I've only seen one. They tend to be
real boat anchors - heavy, oil-filled metal-cased, with large
asymmetrical insulators (a smaller Vdc input insulator and a larger 2X
Vdc output insulator). For example, here is the one I have:
The above oil-filled charging reactor is rated at 67.2H, 122 mA, 15 kV
in, 30 kV out, at 192 Hz (or a maximum of 384 PPS). It weighs about 75
pounds. It was designed to be used with a PFN having a total line-ground
capacitance of ~0.01 uF at 15 kV, delivering a bang size of about 4.5
joules. Unfortunately, the maximum power (at maximum PPS) for a DC TC
using this reactor would only be about 1700 watts.
Hope this helped and best wishes,
Bert
charles rakes wrote:
I'm using a Bendix choke on my dc Tesla coil, that has the following
ratings, 4.8H, 5 ohms, 2 amps dc and a 17KV working voltage rating with a
max of 35Kv . I'm guessing its weight at near 100 lbs or more. I've had
the choke for over 20 years and was wondering if anyone might know what
it's original use might have been? Are there anymore out there? tnx,
Charles
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla
--
Bert Hickman
Stoneridge Engineering
http://www.capturedlightning.com
***********************************************************************
World's source for "Captured Lightning" Lichtenberg Figure sculptures,
magnetically "shrunken" coins, and scarce/out of print technical books
***********************************************************************
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla
