Topband: 160 m inverted L

[Herbert Schoenbohm]

Bread slicers have their issues and are not really the best solution.  
Using a fixed high current mica G2 broadcast capacitor of a higher value 
than you need, and making it variable with a series inductor is the way 
to go.  This is what broadcast stations do in their ATU's.  I haven't 
ever seen a bread slicer in a radio station ATU.  A good high current 
mica cap and a flat wound taped coil IMHO is the way to make everything 
work well with no breakdowns.  For a wide range of matching consider a 
bridge T with fixed components and taped coils.  Go to W8JI's wonderful 
site for the values you need based on the impedance presented to your 
feed-line.



Herb, KV4FZ


On 11/8/2016 6:55 PM, Rob Atkinson wrote:
> A vacuum variable for L impedance matching is unnecessary.  Vacuum
> variable capacitors leak eventually.  It take a long time for them to
> go through their ranges and you have to have the mechanics outside if
> you perform remote tuning, to sense or count turns to track when the
> v.v. is nearing its maximum or minimum.  It is far far easier and
> faster to use an air variable that rotates freely.  You only need to
> keep it sheltered.
>
> Elevated radials are fine provided they are high enough to be
> decoupled from earth, which for most hams is difficult to accomplish
> on 160 m.
>
> 73
>
> Rob
> K5UJ
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