If you are bored, you may want to check out my blog at ka7oei.blogspot.com.
The KA7OEI Microwave page
- A page with some details of microwave-band amateur
radio operations and equipment, including 10 and 24 GHz plus
information about Rubidium and Crystal-based frequency references.
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.
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...
Satellite Page - Some time
ago, I decided to build an APT (Analog) 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. Go here to see the pictures from the weather satellite.
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.
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
Direction Finding (e.g. "DFing"):
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.
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.
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.
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 Friendship Cruise has not been held recently - see its official page for more information.
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!
A remote antenna for 60 kHz
WWVB reception - In the middle of a busy
office building a "clean" source of 60 kHz WWVB was needed to
synchronize some "Atomic" wall clocks, so this system was built to
get a good signal to them. This same method could be applied
to other longwave time signals such as MSF, JJY or DCF77.
Other misc. pages maintained (in whole or in part) by me:
- 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?
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.
Flashlight - Recently, very high-energy,
low-voltage capacitors have appeared on the surplus market that
have enough energy storage to be useful, so a simple flashlight
was built using it. This article describes the technique,
usability and practicality of doing so.
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This page maintained by Clint, KA7OEI.
Last update: 20150513