It sounds strange, because to have 45,6 uH with 20 turns the Al should
be 1140.
With T300A-2 Amidon data (Al = 228), with 20 turns you should have 9,12
uH (103 ohm of Xl at 1,8 MHz).
73 de Guido, ik2bcp
P.S. Guy, please, answer to mailing list, not privately to Andy, because
the answer could interest many people.
Il 17/01/2016 17:24, Andrejs Pankins ha scritto:
William,
Thanks for idea. Are you absolutely right - 5uH is too small for 160m.
Looks like I have a wrong toroid. After playing with amidon toroid
calculator, I found that 20 turns on T300 will give around 5uH (like mine),
T300A-2 will give 45.6uH
Regards,
Andy - YL2QN
On Sun, Jan 17, 2016 at 1:52 AM, William Shanney <wshanney@verizon.net>
wrote:
5.7 uH sounds too low for 160M, I’d want ten times that to keep the
winding impedance >>50 ohms.
Bill, W6QR
On Jan 16, 2016, at 3:44 PM, Andrejs Pankins <yl2qn.andy@gmail.com>
wrote:
Hello,
Need your help. For a long time can't get working FCP for my Inverted L.
I'm looking for some way to check quality of my homemade isolation
transformer. I'm connect primary to 50 Ohm dummy load and secondary to
Antenna Analyzer. Get reading @1850 Ra=28 Ohm and Rx=34 Ohm. Rx is raised
with frequency. Inductance for primary and secondary is 5.7uH.
Capacitance
between primary and secondary is 140 pF.
These reading looks normal or somthing wrong ? I'm expected 1:1 impedance
transformation without additional Rx.
Thanks a lot in advance for your help.
Regards,
Andy - YL2QN
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