Re: Scot's spark gap in progress
Hi Ralph, Scot, All
I am also building a Scot Gap, so here are my comments, and my question
>(...) As I previously posted, I view the accuracy
> requirement for the parallel ditches as being so critical that I may well
> give the milling job to a machine shop.
That is what I did, and even if I spent a lot of time looking around to see
how those machines work (it was the first time I was using them), I can tell
you that is worth the time...
> The locations for the 8-32 screws can be easily spotted and drilled.
> just a small hole neatly locates the centerline for the ditch. Now I have
> question: why do we need the ditch? I drilled several 8-32 holes and
screwed > two of the copper cylinders
> down onto the acrylic. The cylinders hold solid to the acrylic and
> the parallelism
> is a cinch. So why go to the trouble of milling that ditch into the G-10?
With perfectly parallel ditches, you can hold your tubes with only one
screw, and you are sure they will be parallel. Of course the other
possibility is to drill two holes in the pipes and in the G-10. But if you
make a little mistake with the holes on the tubes, and another mistake while
drilling the G-10, those two mistakes will be added, and your tubes won't be
perfectly parallel. But with one single screw and a ditch, I think you can't
Now, allow me to ask you a question about forced air into the gap. Can you
two tell me how you did?
Here is what I'am doing. any comments will be appreciated.
I also have one side with 5 tubes and one side with 4. On the 5 pipes side,
I drilled 4 (diameter 13.5mm) holes (one betwen each tubes) in which I will
put a plastic tube. The 4 plastic tubes will end in a PVC pipe, in which I
will blow air with a vaccum cleaner. On the other face of the gap (the one
with 4 tubes), I drilled 5 ditches that are about the pipes length, to allow
the air to escape. Of course, all the other faces of the gap are closed with
plexi sheets (that's what I used) to force the air to go between each gap
and escape at the top...
Does it seem to be a good idea?
> Happy day,
> Ralph Zekelman
Long life to the Scot Gap!