Re: [TenTec] OT: Openwire Balanced Antenna Tuners (QST Test)

[Steve Hunt <steve@karinya.net>]

Pretty high Q values can be achieved if you choose the toroid mix and 
the winding spec carefully.
For example, according to the Micrometals Q Curve Application 
Information book a T200-6 core wound with 30 turns of #18 wire achieves 
a Q >300 across the range 1.5MHz to 7.5MHz, and peaks at over 400. 
That's significantly better than a commercial air-cored roller-inductor 
I measured at the same inductance value.
73,
Steve G3TXQ



On 18/02/2013 01:54, Bob McGraw - K4TAX wrote:
> I'll take an air-wound inductor over a toroidal inductor any day, 
> space available.  The typical loss in an air-wound inductor is IR loss 
> where a toroidal has IR loss plus eddy current loss.