The OZARK PATROL

    Back    Page 1 Page 2 Page 3 Page 4  

An assembled Ozark Patrol regenerative radio kit. It is produced by the Four State QRP Group.
 

The regenerative radio circuit was invented in 1912 by Edwin Armstrong. The Armstrong U.S. Patent 1,113,149 was granted October 6, 1914. It was an almost miraculous improvement over the radio receivers in use at that time.

To avoid licensing fees, some companies offered kits you could assemble yourself. This may sound a bit under-handed, but the cost of a radio made it out of reach for many households. If you had some basic skills and tools, a radio kit that you assembled yourself would get you a radio at half the price, as well as a bit of pride.

New and  improved versions of regen kits emerged in the 1950s to the 1970s. The most famous of these were the Knight Kit Ocean Hopper and Space Spanner, the Radio Shack Globe Patrol and the Lafayette KT-135 Explor-Air. The Ozark Patrol was designed in homage to these kits.

The kit utilizes a novel soldering technique called "Pittsburg Style," where the components are surface mounted onto a circuit board.
 
The Pittsburg Style technique was invented by Joe Porter, according to the Four State website. Joe is from Pittsburg, ergo the name. The kit is very different in that you solder the components to the circuit board, yet the actual circuitry is hidden from view. The circuit board is also the front panel.

These are the parts you get with the kit. Everything you need is here, except for the batteries (six AA size) and the antenna.
This kit came with two extra transistors and an extra coil form. The plank of wood on the right is the base.
 
As with many kits, no knowledge of electronics is required. If you can follow directions you can assemble the Ozark Patrol.
 
Some of the parts are very small. Years ago this would have been a marvel of science. Today it is a pain in the neck. To assemble the kit you have to identify parts stamped with numbers smaller than the date on a dime, and you have to physically pick them up with human fingers.
The circuit was designed by David Cripe. While you're trying to solder the little capacitors in you can say, "Aw for Cripe's sake!"

 
 
The radio covers 3.5 to 14 MHz. (Even though the largest number on the dial is "12.")
This all short wave, no AM broadcast band. International stations and "hams" are heard.
 

So how well does it work? Not bad for a one transistor regen / reflex receiver (with a two transistor audio amplifier). By "reflex" we mean that part of the audio signal, as well as the radio frequency signal, is used as feedback. The feedback is controlled by the "Regeneration" knob on the front panel.

This radio has an AMAZING bandspread control! The front panel is so shiny that I had a hard time photographing it. Either I or the camera would appear reflected in the panel.

The two transistor amplifier lacks the ability to create adequate amounts of volume and the little speaker sounds tinny, but the earphone jack is there for a purpose. As a matter of fact, you can hear a lot more with headphones than you can through the speaker.

With your headphones on and your nimble fingers on the regen and bandspread controls you can pick up plenty of shortwave stations when the conditions are good.


 

For more information, plans, photos, prices, etc., click on the 4 State logo.

 

 
 NEXT