Hi Frank, as cq-contest reflector is quite slow these days, I paid more
attention to your RX bandpass filters and discovered that capacitor values for
C1/C7, C2/C6 & C3/C5 differ although they should be all the same in 50 Ohms
symetrical system! How comes, OM?
73 de Mario, S56A, N1YU.
>From donovanf@sgate.com (Frank Donovan) Tue Jan 14 12:06:01 1997
From: donovanf@sgate.com (Frank Donovan) (Frank Donovan)
Subject: Interference filters (fwd)
Message-ID: <Pine.OSF.3.95.970114070502.13572C-100000@jekyll.sgate.com>
Hi Mario!
Yes, the capacitor values are unsymetrical, which results in unsymetrical
VSWR at each end of the filter. The filters were developed as a messy
compromise between design simplicity (mainly ease of alignment), VSWR
bandwidth, one dB and 3 dB loss bandwidth, ultimate attenuation at one
suboctave, and "acceptable" attentuation one octave higher in frequency...
It was an awkward compromise to execute in the pre-PC days of the early
1970s, but they do work as advertised! Perhaps with today's real-time
interactive PC-based tools, a more elegant design could be created!
73
Frank
W3LPL
donovanf@sgate.com
>From rvhoeft@ingr.com (Hoeft, Roger V) Tue Jan 14 13:55:15 1997
From: rvhoeft@ingr.com (Hoeft, Roger V) (Hoeft, Roger V)
Subject: Elevated radials for inverted L - how high is good??
Message-ID:
<c=US%a=_%p=INTERGRAPH%l=HQ1-970114135515Z-7050@hq14.pcmail.ingr.com>
Hello all,
What do the experts out there say is the minimum effective height to
have radials elevated for a 160 inverted L. I have the radials and feed
point about 8 - 9 feet off the ground, but all I seem to have
accomplished is RFing the TV through the cable and my sons' personal CD
players. With the location of the L and my yard, I am not able to have
a good, well laid-out field of tuned radials for the L.
I've read about the big dawgs using elevated radials - I guess the real
question is what should I expect, performance wise, from having elevated
radials for the L?
As always, the assistance and information from the reflector is most
helpful and appreciated.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Roger Hoeft
KA9EKJ
rvhoeft@ingr.com
Amateur Radio is a contact sport
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