Re: Vacuum Gaps

At 04:20 PM 09/05/00 -0600, you wrote:
>Original Poster: Esondrmn-at-aol-dot-com 
>I have a spare RQ gap laying around that I plan to modify.
>It currently is open on the bottom with a muffin fan on top.
>I plan to seal the bottom and cut slots in the sides between
>the gap sections then install a new end cap on top with a 
>fitting for an air hose to the vacuum motor.
>Thanks, Ed Sonderman
Hi Ed:

I know your question was directed to Gary, but having just completed
a mod to my RQ gap as you described, I thought I'd reply as well.
I didn't have a way of neatly cutting slots in the PVC between the
copper pipe segments, so instead I just drilled a row of 1/2 inch
holes spaced tightly together.  To direct the air between the segments
I fashioned some large plastic "washers" which where pressed inside
the PVC pipe until they rested on the copper pipe ends.  The bottom
washer has no central hole, while the top one has a hole of about
the same diameter as the inner edges of the copper pipe segments.

For my vacuum source, I used the motor and compressor unit from an
old Filter Queen vacuum cleaner.  It was almost a perfect fit to 
the 6 inch PVC pipe, and I used duct tape to attach and seal it in
place on the top of the pipe.  A variac allows the speed and hence
the airflow to be adjusted for maximum spark output.  It works
quite well with my 6 KV., 250 mA. radar power transformer, with
good quenching and no hint of power arcs.

73, Weazle, VE3EAR/VE3WZL

Listening: 147.030+ and 442.075+
E-mail:    weazle-at-hurontel.on.ca
           or ve3ear-at-rac.ca
Web site:  www.hurontel.on.ca/~weazle