Photo of a "home-brew" Galena Radio
Galena radios deserve a special page of their own in my home page.
These sets take us back to the primordial times of radio, an era in which Marconi and othe self-sacrificing scientists would conduct experiments with the radio waves
The majority of Galena radios are of the home-made construction, thus the great variety of circuits.
The basic Galena radio is resumed by a coil, a capacitor, a Galena crystal rock a high impendance headphone set with the minimum of 2,000 ohms, a good antenna and grounding.
The refinements were up to the builders, who would add to their sets, a variety of components.
The "cat wisker" was the best known component, utilized to find the junction of the crystal detector to the Galena rock, which made tuning of a station possible.
The cat wisker was made of a spiral of ultra fine steel wire on a movable base for operation.
The operation of the radio set it self, is very simple, although not always satisfactory, due to the lack of signal amplification.
Not needing electric current to operate, it was popular in areas where these services were not available.
These sets were employed by troops in times of war, making it ideal to carry, due to the small sizes, needing only to lay out a length of 20 to 30 meters wire antenna to receive transmissions from thousands of kilometers away.
The Galena radio shown above was set in a deactivated explosive mine shell, probably over 60 years ago.
The headphone is a NEUFELDT & KUHNKEKIEL - "N & K".
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Radiguet & Massiot
Constructeur
P A R I S
The "Radiguet" firm was founded in 1872, with production of precision
instruments, scientific games and toys.
In 1889, with the new denomination "Radiquet & Massiot", headquartered
at 13 et 15 Bould des Filles du Calvaire, a neigborhood of Paris,
France, initiates in the field of high tension, high frequency research
and medicine diagnostic instruments, with studies published in 1902.
In 1910, with the new denomination of "Massiot et Cie", relocates to 37
bis rue de Belfort Coubervoie, Seine, yet another suburb of Paris,
producing among other things, retro-projectors.
In that same year, the first wireless telegraph services are inaugurated
in Paris, making possible its citizens to adjust their watches with
greater precision, therefore turning the town into "The Center of The
World".
The station, callsign FL, was located in the Eiffel Tower.
Messiot et Cie ceased to exist during World War I.
A set of rare beauty, with modular metal construction, in a varnished
cedar cabinet.
With 1915 technology, all modules had an inscription "RADIGUET A PARIS",
and the number "328".
In 1890, by international agreement, every manufacturer adopts the now
familiar "MADE IN..." in lieu of the name of the locality where
produced.
The signal from the antenna passes through several coils (left of
photo), interchanged by a 10-position key for adjustments, plus a
fine-tuning feature acheived by the use of a slide-rule cursor, allowing
for tuning from a few kiloHertz, to the top of the MediumWave band.
It features two other coils of the "Inductive Coupling" ( Loose Coupler type ) type for further
adjusting.
The tuning is accomplished by variations of the larger coil tapes,
through a second cursor..
The coupler for the detection phase is done by another coil that is
interned in the first coil, allowing for variation in the coupler.
This second coil has a key with eleven positions, which along with the other
cursors, makes possible a wide tuning range.
The detection phase is composed by a Galena Chrystal and a "Cat
Whisker", with an output to headphone muffs, aided by a sliding cursor,
where the user can add capacitors parallel to the headphones.
This Galena Set is in perfect condition, having needed only a thorough
cleaning after nearly 90 years of storage.
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GECOPHONE Model BC 1385
Wavemeter
Built in 1925 by British General Electric Co. Ltd., in mahogany cabinet.
A radio-frequency measuring instrument, features a variometer with a scale of 0o to 180o, calibrated and adjustable oscilator, bell and battery compartment, capable of exciting a galena set among others, by means of coupling at a short distance.
The ressonance reading and adjustments for frequency conversions are accomplished with the aid of a chart located under the lid.This instrument had several applications such as calibrating receivers, antennas and cat wiskers in galena sets.
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Homemade construction crystal set
This Galena chrystal set has variable capacitor tuning, fixed coil and is built in an Imbuia wood cabinet.
A lateral space is provided in the box, where a set of headphones and antenna can be stored.
This radio has few resources as far as tuning is concerned, since I was able to capture only one local station with it!
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