Clint's Page(s)

The following pages are those that I maintain either in whole or in part.  I hold the amateur radio callsign of KA7OEI, hence the common theme of many of the following links:


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 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.

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.


Other amateur ("Ham") and other radio-related pages:

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!

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:

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.

A Capacitor-Powered 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.

Spectral analysis of a "Powerline" Ethernet modem - A Western Digital "Livewire" modem became available for a short time and curiosity resulted in putting it on the workbench and seeing what it's RF spectrum looked like:  These are the results!  Note:  I don't own this modem so please don't ask for advice about it - just read the page, follow the links and do futher research!

Random Bits - A few completely random comments/repair notes that may or may not be useful to anyone else...

"Old Stuff" - This page has older, not-recently updated content that I moved to de-clutter this page.

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This page is copyright 1999-2012 by Clint Turner.  All rights (and wrongs) are reserved.

The various trademarks and names used on this page are the property of their respective owners and no endorsements or infringements are intended, expressed or implied.

This page maintained by Clint, KA7OEI.  Last update:  20120706
 

Since 12/2010: