Four State QRP Group

Four State

Crystal Spotter
Crystal Spotter

Designed by Jim Giammanco, N5IB
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Kitted and Offered For Sale By The Four State QRP Group

Temporarily out of stock. Be back soon!

Designed by Jim Giammanco, N5IB, the Crystal Spotter uses a classic Pierce oscillator circuit to produce a signal at the series resonant frequency of a quartz crystal. The signal can be heard in a nearby receiver without any electrical connection to the receiver. It is useful for locating a crystal's operating frequency in uncalibrated receivers, or for checking whether a crystal is active.

This low cost kit sacrifices nothing in the way of quality. It features a high quality printed circuit board, with clear silkscreened labelling to aid the builder. There are only 14 components, all of which are conventional through-hole parts.

The construction is "Pittsburg Style" in which the components are soldered onto pads on the top side of the circuit board. This method permits the bottom side to be a continuous, unbroken ground plane, with no protruding wire leads. The board can rest on a metal work surface or reside in a metal enclosure without risk of shorting anything out.

First time builders please note: This kit is easy to build, there are NO tiny surface mount parts, and there is lots of room on the board. The only tools needed are a low wattage soldering iron, and some small long nosed pliers and wire cutters. The builder need only provide a 9 volt battery.

Specifications and Design Features
Frequency range:  Works with fundamental mode crystals from 1 MHz through at least 15 MHz
Power requirements:  Single 9 volt battery, drawing about 11 mA
Battery life:  Current is drawn only momentarily, so a battery should last its shelf life
NO SMT Parts:  All through hole parts.
NO Toroids to wind:  The only inductor is a molded, through-hole type
PCB:  High Quality, silk screened, two sided 2.950" x 1.775" printed circuit board.

Assembly Manual, with Schematic, Parts List, and Photos
Electronics 2000's Excellent Capacitor Identification Page  Posted with permission.
Electronics 2000's Excellent Resistor Code Graphic Calculator  Posted with permission.
STL file for 3D Printable case (top)
STL file for 3D Printable case (bottom)

Photo Page

The Crystal Spotter is carefully kitted and shipped by Johnny Matlock, ACØBQ
Please direct shipping, kit, and part related questions to Johnny
All proceeds are applied toward funding OzarkCon.   Thank you for supporting The Four State QRP Group.
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