Carl Hyde- The Balun I used is from Amidon- They just started manufacturing
W2FMI balun designs.. It's listed as a "direct connect Yagi" rated at 2KW,
and is mounted in an aluminum box with two ceramic feedthrus on one end and
an SO-239 on the other..Part Number is 4:1 HB50- you might want to do an
analysis on the completed antenna before ordering the Balun, to see if you
can get a 50 ohm match @ 1:1 first.. I found the feedpoint Zo to be about 13
ohms (which is what the antenna book says it should be ) so I went ahead
with the Balun.. AB4GX says it can be matched to 50 ohms,
but he also says he had an MFJ SWR analyzer to do it... I didn't get the
analyzer till afterwards, but measured the feedpoint Zo with a noise
bridge.. Since it showed the Zo to be 13 ohms per the book, I went ahead..
also gain is per the book, though I have not measured it, ---seems to be in
line with the antenna book charts, or about 5 Db
Good luck -- Jim W. K1EXE HB50 is $49.95 +S&h
--
FAQ on WWW: http://www.contesting.com/tentecfaq.htm
Submissions: tentec@contesting.com
Administrative requests: tentec-REQUEST@contesting.com
Problems: owner-tentec@contesting.com
Search: http://www.contesting.com/km9p/search.htm
|