-40%
Silver Galena Vertical Crystal Radio Diode Tungsten Cats Whisker Detector Stand
$ 27.42
- Description
- Size Guide
Description
Working and Functional Vertical Crystal Radio Detector StandFor the Experienced and D
iscriminating
Crystal Radio Enthusiast
Also a Very Popular
Mesmerizing
Executive Desk Ornament and Conversational Piece
https://youtu.be/4hMflvGtkFs
Cat Whisker Crystal Radio Diode Stand-
In this video, I record the Audio directly from the Headset to show the volume Level that can be achieved with out any power amplification.
The Volume that you will actually achieve is directly
proportional
to your
signal
strength from your Radio
Precision Brand New Premium Vertical Detector Stand
Premium Solid Large
5"
Diameter, 3/4" Thick Finished Walnut Wood Base
Brass Knurl Nuts For Easy Electrical Connections to your Radio
Extra Large Granular (Specular) Silver Content Australian Galena Crystal
Granular/Specular Silver Content Galena is Rare and more stable than the more common Cubic Galena
Tungsten Cats Whisker
Whisker and Crystal can be easily and quickly replaced
All of the Brass Components are
Precision Machined
The support brackets are Stamped Solid Brass
Whisker and Crystal Positions are Fully X and Y -Axis Adjustable by
repositioning on the Brass Plate
The Up and Down contact point and force can be adjusted by rotating the Black Ball Knob (Loosen the Knurled lock nut to adjust and then tighten the Lock Nut after the adjustment is made)
After any positional adjustments, you must remove your hands or fingers from the detector stand after each adjustment to keep from
loading
the circuit
1) T
o adjust the whisker position contact force, loosen the Knurled Lock nut and rotate the Larger Plastic Ball Knob
(the one that is attached to the end of the whisker rod)
and rotate. Tighten the Knurled Lock Nut after adjustment is made.
2) Position across the crystal top surface can also be sliding the Cast or Raw Mineral in the X or Y axis (always position the whisker away from the crystal surface when sliding to prevent damage to the whisker or crystal-do not drag the whisker
across
the crystal)
Future Options available soon for Conversion to Perikon or Point Probe Detector
Galena
C
rystal Radio Diode Detector Stand in Finished Wood and Base Brass Components
Crystal Radio Diode Stand attached to Wood Base, Brass Hardware and Tungsten Cats Whisker
Cats Whisker: .0085 Diameter Pure Tungsten
Solid Brass and Copper Components
Brand New
Includes a Freshly Sheared and Precision Cast Silver Content Galena Crystal
Included is a precision .632 Diameter Cast Crystal
or use your own Cast or Raw Crystal
Easy Screw Adjustment with knurled nut lockdown secure and provide for a stable contact
Can be adjusted for the Optimum Contact Force
Whisker can be easily replaced from the threaded whisker holder
Quick and Easy connection to your Radio
Premium Solid 3/4" Thick Finished Walnut Wood Base
(Only one Cast Australian Silver Content Crystal is Included with the
Detector
Stand)
Working with a Cats Whisker and Crystal can be very tricky and takes a great deal of patience, time, steady hands and acquired skills.
The surface of the crystal forms a crude and unstable point-contact metal–semiconductor junction that acts like a diode, current can flow from the wire into the crystal but not in the other direction.
The most common type was the so-called Cat Whisker Detector, consisted of a piece of crystalline mineral with a fine wire touching its surface.
Base Dimensions:
Diameter: 5" Base
3/4" Thick
Total
Height
: 4.5"
Replaceable Whisker and Crystal
Finished Solid Walnut Wood Base
4 Silicone Rubber non-skid feet on Base
1
Crystal Detector ( Actual crystal may vary in shape and size from picture)
Crystal mounted and Precision Cast in a .632 diameter casting alloy
Crystal Casting alloy is made from Lead, Tin and Bismuth
Casting Alloy Does Not Contain Cadmium
Fully assembled and tested, ready to connect to your Crystal Radio.
FACTS ABOUT OLD SCHOOL CRYSTAL
RADIO
MINERAL DIODES
Galena Requires only a Very low Contact force from the Whisker is the Best and Most popular Choice among Crystal Radio Enthusiasts.
Galena Mineral is also readily available.
Measuring forward and back resistance ratios of crystal-and-cats-whisker diode. There is a significant difference
between forward and back resistance readings on an ohmmeter, but the ratio was nowhere close to that of a modern germanium diode,
thus limiting the efficiency of a mineral crystal. However, connecting a germanium diode as a bias with the crystal in series or
parallel
can make a major
improvements in performance. In General, Galena and Pyrite can be used with a Series Germanium Diode and Minerals such as Carborundum can be used a
Parallel
Germanium Diode for Biasing.
Not every contact position on the crystal will perform, so fiddling with the ‘cat's whisker’ to find a sweet spot does take patience and a steady hand.
To find a sweet spot on the crystal does take patience and some acquired skill.
The wire whisker is the Anode, and the crystal is the Cathode.
Cat Whisker:
The "cat whisker", a springy piece of thin metal wire, formed the metal side of the junction. Hardened wire of about 30 gauge was commonly used because it had just the right amount of springiness.
Crystals that require a light Whisker pressure are Galena and Pyrite while silicon and Silicon Carbide (Carborundum) requires a heavier Whisker point contact.
Various crystal minerals require just the right amount of pressure by the Whisker wire to work properly.
For example: Too much Whisker pressure with Galena and Pyrite causes the device to conduct in both directions and the Mineral will fail to perform as a Diode.
Crystal Mineral Detector Diode:
It consisted of a pea-size piece of crystalline mineral in a metal holder, with its surface touched by a fine metal wire or needle (the "cat whisker"). The contact between the tip of the wire and the surface of the crystal formed a crude unstable point-contact metal–semiconductor junction, forming a diode. The wire whisker is the anode, and the crystal is the cathode; current can flow from the wire into the crystal but not in the other direction.
Having a lot of patience and a steady hand are needed when you listen with a piece of the rock. But this can also be very rewarding when you can hear the first station using a cats whisker detector.
Please note : This item not a Crystal Radio, but is installed into a Crystal Radio and used to replace a modern Germanium diode with an older technology developed during the 1920's.