Content of Articles in Section A of this Site |
Article # |
Practical design considerations, helpful Definitions of Terms and useful Explanations of Concepts used in this Site: 04/25/00; 11/06/07 |
|
A New Way to Look at Crystal Radio Design. Get Greater Sensitivity to very Weak Signals and Greater Volume, less Audio Distortion and Improved Selectivity for Strong Signals: 07/15/99; 02/12/06 |
|
To maximize volume from headphones or a speaker, measure and use effective impedance. No lab test equipment is needed: 07/15/99; 06/21/03 |
|
Compare the impedance and sensitivity of headphones, earphones and/or speakers even if they differ greatly in impedance. No lab test equipment is needed: 07/15/99; 06/29/00 |
|
The best diode and audio transformer for a crystal radio, and a way to measure diode saturation current: 10/02/99; 08/22/02 |
|
Low-loss Impedance matching for magnetic and piezo-electric headphones, measurements on several audio transformers, and a transformer loss measurement method: 10/22/99; 03/30/08 |
|
A Crystal Radio Diode Detector Simulation using SPICE: 01/02/00; 11/23/01 |
|
Diode Voltage vs Current Curves: Does an Actual Knee Voltage really Exist?: 01/08/00; 05/25/00 |
|
Crystal Radio Diode Detector Power Loss with Current with Voltage Waveforms, as Determined from a SPICE Simulation: 02/13/00; 11/25/01 |
|
Build the Diode Detector Bias Box: a simple and easy way to determine if one's diode is optimum for weak signal reception, or should have a higher or lower axis-crossing resistance (0.026*n/Is): 03/30/00; 01/24/07 |
|
A New Diode Detector Equivalent Circuit, with a Discussion of the Linear to Square Law Crossover Point: the signal level at which the detector is functioning midway between linear and square-law operation: 04/04/00; 10/27/2002 |
|
A Procedure for Measuring the Sensitivity (Insertion Power Loss), Selectivity and Input and Output Impedance of a Crystal Radio: 07/21/00; 04/10/2003 |
|
Directivity of the Inverted L Antenna with speculation as to why it Occurs and how it might be enhanced: 07/29/00; 11/20/2005 |
|
How to Measure the Electric to Acoustic Transduction Power Loss of Magnetic and Ceramic Earphone Elements, with Measurements of some Headphone Receiver Elements: 08/30/00; 10/28/2004 |
|
A Zero Loss, Unilateral 'Ideal' Audio Transformer Simulator plus... This device makes it very easy to determine the optimum audio transformer input and output resistances for any diode/headphone combination. No test equipment necessary: 01/05/01; 01/17/2010 |
|
Quantitative insights into Diode Detector Operation derived from Simulation in SPICE, and some Interesting new Equations relating diode SPICE parameters to weak signal sensitivity: 4/10/2001; 12/07/2008 |
|
A Procedure for Measuring the Saturation Current Is, and Ideality Factor n, of a Diode along with Measurements on various diodes: 03/28/01; 02/10/2004 |
|
New ways to Increase Diode Detector Sensitivity to Weak Signals, and a way to determine if a diode detector is operating above or below its linear-to-square-law crossover point: 04/10/01; 11/29/2006 |
|
Get 3 dB More Output for Greater Volume on Strong Stations plus...: 07/09/01; 04/06/07 |
|
An explanation of how the "Mystery Crystal Radio" works: 08/11/01; 12/29/02 |
|
How to Measure the Impedance of an AM Band Antenna-Ground System, what one can do with the results, along with some measurements: 11/24/01; 04/16/2004 |
|
Design, construction and measurement of a single-tuned crystal radio set using a two-value inductor, along with a discussion of the cause of 'hash', short-wave ghost-signal and spurious FM reception. A way is presented to determine if the signal operating the detector is above or below its linear-to-square-law crossover point: 02/07/2002; 08/20/2006 |
|
How to Make a Very Efficient Double-Tuned, Four-Band, MW Crystal Radio Set using two Version 'b' Single-Tuned, Four-Band, MW Crystal Sets 02/07/2002; 07/27/2002 |
|
Sensitivity and selectivity issues in crystal radio sets including diode problems; measurements of the Q of variable and fixed capacitors, RF loss in slide switches and loss tangent of various dielectrics: 03/25/2002; 06/10/2008 |
|
A new approach to amplifying the output of a crystal radio set, using energy extracted from the RF carrier to power a micro-power IC to drive headphones or a speaker: 07/04/2002; 02/25/2003 |
|
Highly sensitive and selective single-tuned four-band crystal radio set using a new contra wound dual-value inductor, and having a 'sharp selectivity setting'; along with a way to measure the unloaded Q of an L/C resonator: 02/10/2003; 10/23/2006 |
|
Measurement of the senstivity of a crystal radio set when tuned to a weak fixed signal, as a function of the parameters of the detector diode; including output measurements on 15 diodes: 08/14/2003; 08/19/2006 |
|
How to Reduce Diode Detector Weak-Signal Insertion Power Loss to Less than that Possible when the Input is Impedance Matched Originally released as Article #15, later withdrawn Republished as Article #28: 03/04/05 |
|
About Maximizing the Q of Solenoid Inductors that use Ferrite Rod Cores, including charts of Magnetic flux density and lines, with some actual Q and inductance measurements: 10/07/06, 01/07/08 |
|
