Topband: Any way to check isolation transformer for FCP

[Andrejs Pankins]

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 at 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 at 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
> > _________________
> > Topband Reflector Archives - http://www.contesting.com/_topband
>
>