On Wed, 7 Apr 2010 21:42:14 -0700 (PDT), bpnjensen
wrote:

On Apr 7, 2:44*pm, wrote:
On Wed, 7 Apr 2010 14:19:12 -0700 (PDT), bpnjensen





wrote:
On Apr 7, 2:16*pm, wrote:
On Wed, 7 Apr 2010 13:28:18 -0700 (PDT), bpnjensen

wrote:
On Apr 7, 1:20*pm, dave wrote:
bpnjensen wrote:

Dale at PAR advertises that his matching transformer is wound on a
binocular core...but he does not go into precise detail. You'd have to
buy one and disassemble the unit casing to find out.

Bruce

Maybe we shouldn't have chased him away...

We've lost more smart people that way...

I think it was the part about buying one and disassembling it. Could
be using one of these. Probably type 43.http://www.surplussales.com/Inductor...FerMisc-5.html

Jim

Indeed! *I bet I know which one Dale uses ;-)

Maybe even cheaper with instructions and diagram:http://www.aytechnologies.com/TechData/9-to-1_XFMR.htm

Jim

Thanks Jim - I have two compound questions about this diagram that he
does not answer in the FAQ:

1 - In this wrapping technique, does the 50 ohm node at upper left
lead electrically to the 450 ohm node at upper right, or the feedline
ground? I assume the latter, but...this technically creates a half-
wrap somewhere, which would give either 2.5 or 3.5 turns. Same for
the 450 ohm node. It is not obvious from the diagram or the text.

You would have 3 turns on one side and technically 2.5 turns on the
feed side but this would be completed in the connection to the radio.
Same for the other connection to the antenna. 9 turns on the opposite
side and 8.5 turns to antenna. This is how I see it.

2 - Is it automatically assumed that the feedline ground also goes to
a ground rod (somewhere?), or just the coax outer conductor? What
happens if there is no radio ground, just one at the antenna ground,
or vice-versa? What if both grounds are at the same rod?

Since there is no ground available the feedline ground just goes to
the coax outer conductor. Connnect the antenna and feedline grounds
together at the balun. Also, try them disconnected. Whatever gives the
least noise, best signal.

If something close to ground like a window frame or metal railing is
avaliable connect that to either or both ground connections. It
depends on where the noise is coming from which will work best.

Whatever you do, always disconnect the antenna if there is lightning
in the area.

Just wonderin'... :-)

Bruce