Bologna - Italy Oct 10, 2002
Following 11 -13 september postings by:
Re: Flag Xfmr Measurements (gary nichols)
Re: Flag Xfmr Measurements (Tom Rauch)
Re: Flag Xfmr Measurements (Maurizio Panicara)
and
Following 28 september messages by:
Pennant XFMR help (Luis Mansutti IV3PRK)
Re: Pennant XFMR help (k6se@juno.com)
Dear topband reflector friends,
Thanks to all for each contribution to the matter, I would like to give some
more data that could be of help as well:
Since I have also measured a less than optimal swr using FT140-43 at 1.830 MHz,
me and my father Romano, I4FAF, we have tested
other Ferrite Cores (original from Amidon) and we have got the following data
measured with a new MFJ269 and with a resistive trimmer
as a resistive closure to the secondary winding trimmed to 950 Ohm (with a
primary and secondary windings in opposite sides of the core):
FERRITE TOROIDAL type: FT-114-F (3000 permeability) see here link to
ferrite data from the manufacturer:
http://www.amidon-inductive.com/associates_prod_toroidal.htm
enameled wire diameter 0.80 (millimeters, metrical)
primary number of turns: 5
secondary n. of turns: 20
at 1.830 MHz R=51 Ohm Ros= 1,3
at 3.800 MHz R=51 Ohm Ros= 1,8
at 7.000 MHz R=62 Ohm Ros= 2,9
I believe it is a reasonably good result to cover both 80 and 160 meters.
Best 73. Sergio, IK4AUY
Our web-site: http://www.qsl.net/ik4auy/ (with a lot of links technical,
antennas and more)
e-mail: ik4auy@arrl.net
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