Welcome to my first DX crystal radio set page. I first need to give credit where credit is due:
The Rap 'N Tap forum, which is loaded with great info and people.
The Birmingham AL, crystal radio club which runs a contest each year that gives us a goal.
The RadioBoard, sponsored by Dave Schmarder also loaded with great info and people.
Dave Schmarder, who makes some truly wonderful radios which are a pleasure
to look at and I'm sure are a pleasure to operate. Dave has loads of parts you can
purchase.
Mike Peebles, who just called me out of the blue last winter after the 2007 contest, and has
become a great source of encouragement and even more parts!
The design of my set was inspired by Wayne Thelen, who used pluggable coils on the broadcast
band for hi/lo to optimize the Q.
View from front -- Antenna tuner (ATU) on the left, detector on the right. ATU still needs a dial marker. Notice that the coils are really up and away from most of the parts. All the white plastic you see is 1/8 inch thick HDPE. The coil forms were cut by Mike Peebles on a scroll saw (thanks Mike!)
View from right side -- 100/46 litz from variable cap to coil taps, hard to see in photo but it's there, trust me ;-)
View from left side -- with the banana plugs I can tuggle, series or parallel the coil on the ATU
How the spider coils are seated.
The hobbydyne
View from back left
I have about 10 local powerhouses, which require 2 very serious wavetraps.
I must give credit to Jack Bryant for the wavetrap configuration, he suggested it before the 2007 contest.
For the 2007 xtal contest I used 26 gauge on 82-61 toroids, but the litz on the larger toroids is a big improvement.
I have not yet mounted the wavetraps, but will hopefully get around to it soon.
The wavetraps use variable caps, and use 100/46 litz wound on 140-61 toroids from CWS-bytemark.
About 6 turns of 100/46 litz from the antenna lead through the toroids for the coupling and the traps work very well.
For those interested in construction methods, here is a description of how I