[TowerTalk] Tuners

[Steve Hunt]

Paul,

I made the measurements myself. The inductor was in the open, sitting on 
a wooden baseboard. It had a "tapered pitch".

The Qs I measured seem to be similar to those measured by Tom W8JI who 
says this on his web site:

"The trend of Steve's data agrees with my measurements, although there 
are differences in data because I measured different inductors. I 
measured less peak Q, but also significantly higher minimum Q in the 
inductors I tested. While the inductors I measured has less delta in Q, 
they also had a serious dip in Q up near 25-35 MHz when near 
half-inductance."

73,
Steve G3TXQ


On 29/11/2010 17:50, Paul Christensen wrote:
> Steve,
>
> Do you know if the plots were obtained with the roller inductor placed away
> from surrounding objects -- or placed within a metal cabinet?  The Q looks
> pretty pathetic above 40m.
>
> Also, anyone know if Q improves toward 10m when using a roller inductor with
> a non-linear turns count that allows for more turns per unit of inductance
> at one end? (e.g., Cardwell 229 series)
>
> http://www.cardwellcondenser.com/PAGES/md04g.html
>
> Paul, W9AC
>