Dan's crystal set

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The "Galenatron"                                                                           17 Dec, 2000

 The "GALENATRON" is a set that I had wanted to build for a while, so when the contest was announced I "got off the fence" and built it. I wanted to make a set so that it would appear as vintage as possible without tearing what's left of my hair out finding true vintage components. Hence the variable capacitors are a little on the modern side and the modern 1N34 diode used as one of the detectors is "camouflaged" under a modified bottle-top.

 The name "GALENATRON" comes from the practice in the early days of radio of giving some sets a scientific sounding name. This set uses as a primary detector a galena and cat-whisker assembly. There is a selector switch that switches between the galena detector and a diode. Sometimes I like to kick back and listen for long periods and I don't like to be interrupted by re-setting the cat-whisker. Switch it over to the diode and that's that.

 Physical Description:
The "GALENATRON" is housed in a walnut case I made in my woodshop and has a Plexiglas front panel that is painted semi-gloss black to simulate bakelite. The top is hinged and a tuning card is affixed to the inside of the lid to aid in figuring out where the set is tuned. Tuning is accomplished with the left-hand tuning knob. The right-hand knob controls the wavetrap frequency while the center knob controls the variocoupler. This variocoupler consists of the tuning coil, the antenna coil, both of which are fixed, and a rotatable wavetrap coil. The phasing of the coil controls the depth of the null. The labels on the front panel were all done on either AutoCad or Paint Shop Pro, version 5. All wiring was done with cotton-covered hookup wire to lend a vintage appearance to the set.

This set is one of my better performers. The balance between sensitivity and selectivity is very good. Within 25 miles are two 50,000 watt stations on 620 KHz and 750 KHz. Not only can I completely separate them but I can also in the evenings clearly pick up KNBR - 680 KHz from San Francisco between them with little interference. By the way, KNBR is more than 600 miles away! The wavetrap is very good. The combination of tuning and coil phasing gives me a powerful tool in reducing interference. The antenna is a 175 foot longwire up 30 feet aligned NW-SE with me at the NW end. I use an 8 foot copper ground rod as a ground connection.

 This set was a lot of work but all in all was worth it. I hope you can get some ideas from it that you can use in your future projects.


Good luck to all.

Dan Petersen
e-mail: petersen@worldaccessnet.com