If you are bored, you might want to check out my blog at ka7oei.blogspot.com.
Misc. VHF/UHF/Microwave/Light:
The KA7OEI
Microwave page - A page with some
details of
microwave-band
amateur radio
operations and equipment, including 10 and 24 GHz.
KA7OEI Optical Communications page - This page has information about through-the-air optical ("lightbeam") communications using various types of light sources It is linked from the modulatedlight.org page.
Comparison
of
coherent
versus
nonconherent
light
for
transmission
of
audio
on
an
atmospheric path - Did you even wonder if the
phase-coherence of Laser light might impede the effective
transmission
of
amplitude-modulated intelligence on an optical communications
circuit
over an atmospheric path, and whether or not noncoherent light may
provide superior performance under similar conditions? I
did, so
I decided to check it out...
Weather
Satellite
Page - Some time ago, I
decided to
build a VHF Weather Satellite receiver from scratch
-
that's to say, not
from a kit. Here is a page that describes the receiver and
antenna - plus a link that will show recent pictures obtained with
this
receiver.
The
UARC
Synchronous/Voting repeater project - In 2009, a
long-running project by the Utah Amateur Radio Club was completed
in
which two sites - on the same frequency - were linked together to
act
as just one repeater with a large coverage
area.
For this project I was the main designer, organizer and builder of
the
equipment used to accomplish this, the result being a two-site
system
that provides seamless coverage for those moving between the
service
areas of these repeaters. The linked page provides a brief
overview of the project and how its various pieces go together.
A
product
review of a Yagi - This page
describes
in some
detail a Yagi that a fellow amateur radio operator bought on
Ebay a few years ago.
It would be true to say that no antenna performs nearly as
well
as this
antenna!
Direction Finding
(e.g.
"DFing"):
KA7OEI ARDF
page - This page provides
a
point-of-reference
for various Amateur Radio Direction Finding topics - particularly
for
pages relating to the Montreal I, II and III
Doppler
DF units by VE2EMM - including "alternate" firmware for those
units
that can provide additional functionality. There is also
information on a simple PIC-based TDOA unit and a few links to DF
topics in general.
LowFER/MedFER:
The "CT" MedFER Beacon page - These pages describe a PIC-based PSK31 MedFER (Mediumwave Frequency Experimental Radio) beacon on 1704.9something KHz as well as covering a few other LowFER/MedFER topics.
QRSS and
You... - This page explains QRSS
(extremely
slow CW) its advantages, and how
to use it to receive weak/distant signals. Although it is
somewhat dated,
but you may still find it useful.
Using
your
computer to ambush unsuspecting NDBs -
This
page describes
a bit about NDBs and their properties and how one may use a
computer to
aid in their reception. This is also somewhat dated, but it
also
may be useful if you are learning how to use the Spectran program.
A
Line-Synchronous
Noise Blanker for VLF/LF/MF use - This is a
noise blanker
designed
to attenuate noise generated by line-operated devices (light
dimmers,
etc.)
Special attention has been paid to the design to minimize
broadband IMD
produced
by the blanking action.
The KA7OEI FT-817 pages - This collection of pages describes in some detail the inner-workings of the FT-817, as well as various things that can be done to improve the performance of the transceiver.
The KA7OEI GPS page - This page talks a bit about using an HP3801A GPS receiver as a time/frequency reference.
Clint's
Friendship
Cruise page - This talks about a
public
service event
where we set up temporary repeaters to cover a large geographical
area
in some of the most rugged terrain in the U.S. This page
talks
specifically
about those areas in which I have been directly involved.
The Cycloid
Dipole - Developed for use with
the WA7X
beacon, I derived
2 and 6 meter versions of the "Cycloid Dipole" - an odd-looking
antenna
that exhibits omnidirectional, circular polarization radiation
patterns
at the horizon.
Restoring my Atwater Kent Model 20 Compact receiver - This page describes how I restored an old Atwater Kent Model 20-C receiver to operating condition - and how it was used for NDB reception!
Other misc. pages
maintained
(in whole or in part) by me:
modulatedlight.org
- This web site has information about
through-the-air
optical
("lightbeam") communications using various types of light sources.
The Repeaters of the Utah Amateur Radio Club (UARC) - This page has detailed information about UARC's repeaters, including the 146.62 synchronous (simulcasting)/voting repeater system in which two repeaters operating on the same frequency operate as a single, wide-coverage repeater.
The Utah VHF Society
page - This is the official web page of the
Utah
VHF Society which, in addition to providing technical and
financial
support for repeater operators in Utah, provides Frequency
Coordination
in the state of Utah.
Miscellaneous
miscellany
(that is, things that don't fall into the above
categories...):
The Cybernator - This is an ad for a device that may be useful in the field of speech therapy: Get this for a person that talks too much, too little, or just likes the sound of his/her own voice!
A
Cold-War Mystery - In the mid
1950's, after
an above-ground
bomb test, this boat limped into Truk lagoon: What happened
to
it?
The
NiCd/NiMH
page - This
page describes in
some detail the care and feeding of NiCd and NiMH cells and
batteries.
This explains how to keep NiCd cells going, and what that "memory"
affect
really
is! (Hint: It's not the "memory" effect at all!)
The "Floaty-Thingie"
-
This device puts a small maintenance charge on NiMH cells to
counteract
their tendency to rum themselves down during non-use to prevent
their
being dead when you really want to use them! It can
also
be used to catch cells that are on their "last legs" and should be
discarded.
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This page maintained by Clint, KA7OEI.
Last
update:
20120511