"Jeff Liebermann" wrote in message
...
On Wed, 18 Nov 2009 07:00:26 -0600, "amdx" wrote:
The CENTER of the driven element (the plastic screw hole) to the
CENTER of the last director is 36.7cm (14-7/16")
Thanks. My numbers came out to 36.52 cm which is close enough.
ALL directors or the same length (within .003")
They are 46.6mm in length.
Amazing...
Also, measure the coax balun cable dimensions. Mostly, I'm interested
in the:
Nice. I'll see if I guess(tm) the coax type. It doesn't seem like a
good fit for any of the common cables as the center conductor is
somewhat larger diameter than any of these listed. See if you can
find an exposed center conductor without any tinning or soldering.
http://www.epanorama.net/documents/wiring/coaxcable.html
One more dimension... the approximate outer jacket diameter of the
coax (not including the shrink tube).
My guess is solid poyethylene, if you have a test other than poking it
with a pin to get feel of it, which I did.
Weird(tm). Low loss coax would need to be foam or teflon. Solid
polyethylene is easier to work with, cheaper, but not the best.
However, a short piece like this balun would not have much loss, so I
guess it doesn't matter what flavor is used:
http://en.wikipedia.org/wiki/Coaxial_cable
Gotta do paying work today. I'll play with this more in the next day
or two (so I don't forget what I'm doing).
Jeff Liebermann
I have found the need to work for a living, gets in the way of a lot of
fun!
I took the coax loose on the MFJ-1800 and and removed the toroids, I found
the letters found M1Z/111-RG and then the insulation ended. Argh!
Oh, I have a second antenna, so I took that one apart, Eureka! RGS-303
http://wireandcable.thermaxcdt.com/i...d-70-?&seo=110
50 ohm coax. PTFE center insulator, FEP jacket.
Mike