Gollum´s Crystal Receiver World

Simple crystal receiver with ferrite pot core coil.

With a 500 pf solid isolated tuning cap and a ferrite pot core coil you can construct a simple but sensitive xtal receiver. Use a pot core RM6 and r.f. litz wire 40*48 AWG

Crystal receiver with variable antenna coupling.

Spider Web Coil Receiver.

High selectivity, high sensitivity. DX receiver

Triple tuned crystal receiver with spider web coils.

Dual circuit. High selectivity, high sensitivity.

"Mystery Set".

Double tuned variante by Gollum.
Construction plan

Crystal receiver with transistor amplifier using home brewed salt-battery.

Crystal receiver with silicon diode.

Construction plan. Germanium diodes are usually for detector receivers. These diodes can process weaker signals. If you want to use silicon diodes, you must operate these diodes with a bias voltage. The receiver works with a 1.5V battery. You can use magnetic or crystal phones.

Crystal receiver with bias voltage.

This principle is good for reception of weak signals of Germanium diodes. For use of silicon diodes is the bias voltage necessary.
My tests with an AA112 and an OA90 (Germanium types) haven't produced any audiable improvement. You finds these bias voltage schematics in the literature again and again. The bias voltages were needed for definite semiconductors within the early years of crystal receivers. You can use this plan also for Schottky diodes. You can use magnetic or crystal phones.

Crystal set with LED.

The LED needs a bias voltage, here realized with two 1.5 volts batteries. Adjust the 10 k ohms pot for loud and clear modulation. Has your local broadcast station a HIGH field strenght you can see the modulation. This construction is designed for use with crystal ear phone, but it will work also with magnetic phones. Remove the batteries after operation or add a switch.

Rust crystal set

Rust as rectifier for a crystal set

Crystal receivers with transistor amplifier.

Construction plans for receivers. The here shown transistor receivers don´t need any power supply or battery, they are self-powered.

Ferrite rod crystal receiver.

Reception without antenna and ground.

Push pull rectifier receiver.

When you will use a crystal phone read these notes.

Detector with good audio frequency signal.

For crystal- and magnetic phones.

Old-time high selectivity crystal receiver.

Construction plan of periodical "Funk-Bastler", 1926, volume 9, page 109 with 4 coils. Coil 1 and 4 with 90 turns, coil 2 and 3 with 45 turns, diameter 1 inch. Tuning capacitor 500 pf.

Translations:
Bewegliche Spulen = movable coils
Feste Spulen = Fixed coils
Zwischenkreis = Coupling circuit
Detektorkreis = rectifier circuit

(More details for translating German to English here.)

Crystal receiver created by Werner Diefenbach.

Found in periodical "Funktechnik 10.1953, page 307". 2 bands: MW, LW, crystal phone, C= 500pf.

Translations:
Bereich = Area
Spule = Coil
Draht = wire
Aufteilung in Kammern = Separation in sections
Anzapfung bei Windung = Tap at winding
Iduktivität = Inductance
HFL = r.f. litz wire

(More details for translating German to English here.)

Homebrew crystal detector for your crystal receiver.

A more simple rectifier created of a rusty tie you will find here.

Extraterrestrial Crystal Receiver.

No joke. With a little piece of iron meteorite from Canyon Diabolo in Arizona, U.S.A you can create a fine working crystal rectifier for every crystal receiver. Perhaps you will use this holder for the crystal. A very simple rectifier created of a rusty pliers you will find here.

A.f. test unit for comparison of different ear-phones.

With this a.f. unit you can compare and use crystal phone (1), normal magnetic headphones (3) and sound powered headphones (2).Connect ground and diode of your xtal set with the test unit. Disconnect components from a.f. side of diode. Example of a.f. unit in use. In case of sound powered head-phones use an a.f. transformer (100 Kohms to 500 ohms e.g. for DLR5H phones). More information here.

Project 1. Experimental Crystal receiver.

Diode, capacitor and crystal phone for this plan you can order here. I have received with this receiver 11 broadcast stations here in Berlin at night! Frequency range 5.0 - 10 MHz. For crystal- and magnetic phones.

Project 2. Simple Crystal receiver.

Frequency range 6-14 MHz. I have received in Berlin, Germany at night broadcast stations. When you will use crystal phones read these notes.

Project 3. DX Crystal receiver with spider web coil.

You can use magnetic- or crystal phones.

FM-Band slope crystal receiver .

You can use magnetic- or crystal phones.

Most visited page of this site. Details

What is the longwave band?
Because in America, Australia and most regions of Asia and Africa this booadcast band is not in use, here more information.

Loop (frame) antenna crystal set.

You do not need ground or antenna. The frame coil is antenna and resonance coil. The dial of a frame antennas x-tal set can be calibrated because there isn't a dependence of various antennas. When you will use crystal phones read these notes.