[Elecraft] KPA1500 in the IARU Contest Last weekend

[CUTTER DAVID]

Skip

Was any attempt made to redress the imbalance?

David G3UNA

> On 17 July 2020 at 03:19 Fred Jensen <k6dgw at foothill.net mailto:k6dgw at foothill.net > wrote:
> 
> 
>     They were around somewhat before the patent in several forms, and they
>     were around in 1960, which is the last time I looked hence my estimate
>     of 60 years.  Lots of other "balanced" antennas fed with open line were
>     also in use commercially during that rough period, they too exhibited
>     the same characteristic ... while carefully engineered to be balanced,
>     RF currents in the two wires never were exactly balanced, which was the
>     original and only point.
> 
>     I still have an RF ammeter in my junk box, from some airborne WW2 radio
>     I think.  It's probably an antique by now.
> 
>     73,
>     Fred ["Skip"] K6DGW
>     Sparks NV DM09dn
>     Washoe County
> 
>     On 7/16/2020 5:47 PM, donovanf at starpower.net mailto:donovanf at starpower.net wrote:
> 
>         > > Hi Skip,
> > 
> >         Conceptionally you're correct about rhombics and V-beams but your time
> >         frame is way off.
> > 
> >         Edmond Bruce's rhombic antenna patent was filed in 1931.
> > 
> >         www.aktuellum.com/mobile/circuits/antenna-patent
> >         <https://www.aktuellum.com/mobile/circuits/antenna-patent/>
> > 
> >         ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=1685103
> >         <https://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=1685103>
> > 
> >         The heyday for the rhombic ran from the 1930s through the 1970s with
> >         the advent of satellite communications.  The 200 foot tower for my
> >         40 meter stacked 3 element Yagis came from a decommissioned
> >         Laport Rhombic installed at the NSS receive site in Cheltenham MD.
> >         We removed it in 1985, but it hadn't been used for years.
> > 
> >         73
> >         Frank
> >         W3
> > 
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