Owen's set

Photo and Text information

Owen also has a web site for his radio it is http://www.glynn.k12.ga.us/~opool/entry/compressotron.htm

The Compressotron Crystal Receiver and Companion Antenna Tuner
by Owen Pool WB4LFH

    This receiver is designed to be operated as a stand alone receiver or in conjunction with the companion antenna tuner.  It is a "hardware store" special, except for the wire (scavenged from a telephone cable),  a craft bead, some nichrome wire (nipped from a physics lab storeroom), and the galena crystal (found in the same storeroom).  The design is rather straightforward:  The receiver uses a solenoid wound coil with two detector taps, and  connections for an antenna and ground.  Connections are made using wing nuts.  The antenna tuner, also of conventional design,  may be configured for either  serial or parallel operation.
    Unusual construction features are the compression capacitor design, stolen elsewhere, and the clothespin holder for the catwhisker rod (original for me, at least).
    Operation of the set, with the singular exception of the detector, quite frankly stunk.  Oh yes, I was able to pick up the locals and a few of the bandmarker dx stations, such as WSM and WBT, but the capacitors were so touchy that tuning was a frustrating exercise, and quickly abandoned.  The T-nuts used for holding the tuning bolts (hidden behind the furniture knobs), were cut short to match the front panel thickness, and contributed greatly to slop in tuning, as did the nylon bolts, selected to reduce hand capacitance, but which fit rather loosely in the threaded T-nuts.  Adding to this was the aluminum flashing used for the 3" x 5" capacitor plates, which tended to wobble during tuning.  I may go this way again, but I might not, and I won't complain about the price of air variables any more.

Notice the absence of fancy switching and labels.  This is a one-man rig, and definitely not ready for prime time.  Besides, I hate to throw good money and time after bad.  Any needed connection changes are made by taps led out to wing nuts.

Rear view of receiver, showing detail of two-plate capacitor.  The dangling wire is one of the two detector taps, ready to wing nut into place.
(dates on pictures came with the borrowed digital camera)

The detector stand.  This worked fine and holds a point well.  The rock is held down by a modified safety pin.  Should have just entered it and forgotten about the rest.