David W Knight
Ottery St Mary,
Devon, UK.

David W Knight

Precision RF bridge
From Transmitter to Antenna:
HF power transmission theory and practice
AC theory, Components and Materials, Inductors and Transformers, Impedance matching, RF bridges.

Fixed vacuum capacitor

Coil resonance experiments
Low-pressure gas ionised by the electric field of a resonating inductor.
see: coil resonance experiments.

Recent additions:
2015, Aug. 10th: Antenna impedance and matching solution calculator [Windows program], by Alexandr Fedaiev.
2015, June 11th: English translation of Paul Drude's 1902 paper 'On the construction of Tesla transformers: Period of oscillation and self-inductance of the coil.'
2015, March 27th: English translation of Cassou & Cayrel 1934, 'Remarks on the self-capacitance of coils'.

Gas discharge tubes
Gas Discharge Tubes,
spark gaps & thyratrons

Frequency display
Digital Frequency

Andy Cowley's
Valve Pages

(see also: Introduction)

Nixie tubes
Nixie and other digital indicator tubes.

Demodulators and signal rectifiers
Demodulators and
sigal rectifiers


Kenwood TS430s
Commercial radio equipment. Notes & mods.

Using the SGC 230 'Smartuner' in a balanced antenna configuration.

Racal RA17
Racal RA17:
Adapters, etc.

Astronony &
Radio Astronomy

Web Links -
Radio & Electronics

Last uploaded: 20th Aug. 2015 (3440 files, 356MB)

Neon tube