[Elecraft] Practical K2 versus K2/100

[Ron D'Eau Claire]

That's an interesting report, Bill. 

One thing to consider (because it plays a HUGE role in my small QTH) is
that it's the "Effective Radiated Power" (ERP) that is a big issue. 

Most ops can put up an antenna for 10 meters, or even as low as 20
meters, that has an ERP equal to a dipole in "free space" - or very
close to it. Indeed, a fortuitous height in the under 40 foot range can
produce significant low angle gain for a horizontal 20 meter dipole -
several dB over a dipole.

But it's a different story down on 80 and 160. Dipoles at 1/2 wave high
(120 to 240 feet up!) are not too common. Full sized 1/4 wave vertical
out in the clear and with good high-efficiency grounds or 1/2 wave
vertical (120 to 240 feet to the top) are probably no more common.
Almost all ops work with a fairly "lossy" antenna at 80 and 160 compared
to the higher frequency bands. 

So 5 watts on 10 meters into a good dipole might be 10 or even 20 watts
ERP. 

The same 5 watts into a doublet or vertical on 80 or 160 might produce 1
or 2 watts ERP, or less.  That's an S-unit or two on most "meters".

Then, as you point out, you have to add the higher band noise covering
up those weaker signals down on 80 and 160...

Ron AC7AC
K2 # 1289

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Subject: Practical K2 versus K2/100

The attempt here is to examine the 160- and 10-meter claimed scores from
the ARRL contests conducted in the fall of year 2002 for how differences
in power affected the results. The hypothesis is that higher power is
required on the lower frequency bands to overcome the effects of noise
and vagaries of propagation.
...
Bill, NI5F