But what about at 100 mHz and 200 mHz? I worry that a) there is no
filtering of harmonic energy through the windows (no pi network), and that
the inverse square law is significant when the antenna is 100 feet away and
an vacuum tube admirers corneas are inches away.
I have never measured this, though many years ago I did perform part 15 EMI
testing on communications equipment and discovered that small rectangular
slots passed lots of RF energy.
'Festooned with fingerstock and nickel paint"
----- Original Message -----
From: "R.Measures" <firstname.lastname@example.org>
To: <TexasRF@aol.com>; <email@example.com>; "AMPS" <Amps@contesting.com>
Sent: Tuesday, March 02, 2004 3:24 PM
Subject: Re: [Amps] 2 x 8877
> >Whoa, wait a minute! That 150cm by 100 cm opening might be a waveguide
> >cutoff but the attenuation for this size opening is pretty low according
> >the Bill Orr Radio Handbook.
> ** My guess is that, at 28MHz, the radiation from the antenna is at
> least 30db stronger than that from the window. .
> >The chart for this size opening shows a constant attenuation from about
> >1000mhz and lower frequencies on the order of 8db per inch. If the metal
> >is .125
> >inches thick then the attenuation is on the order of only one db!
> >When the opening is reduced to .125 inches the attenuation is on the
> >124 db per inch from about 2000mhz and down. With that level of
> >attenuation a
> >.125 inch thick screen would have about 30db of through loss.
> >Cutoff means there is signal attenuation, not a total loss of
> >73 de K5GW
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