The Spark Gap

Meridian Amateur Radio Club Newsletter Publications 2008

Click Here for Old Issues

Please support the Sponsors that support this newsletter.

---

By Frank WG5X

The Spark Gap transmitter, first demonstrated by David Edward Hughes in 1879, was one of the early forms of generating electromagnetic radio waves. If you remember from your high school science, German physicist Henrich Hertz demonstrated that electrical energy does not leave a wire unless the flow of current is being started and stopped. Around the turn of the century, the rotary spark gap oscillator was how this was accomplished. The speed of the motor also controlled the wave length of the transmitted signals. This form of generating radio frequency was extremely broad banded and soon after the perfection of better oscillators was outlawed because it caused so much interference.

The Italian electrical engineer and inventor Guglielmo Marconi is generally credited with being the inventor of radio. For his efforts he received the 1909 Nobel prize in physics. One of the early methods for detecting these radio waves was with a tank circuit attached to a galena crystal and a crude antenna. This was one of the first solid state devices and was soon replaced by the vacuum tube. It took another fifty years for the semiconductor detector to be reinvented.

My Dad (W5MAV) used a spark gap transmitter and a crystal detector receiver when he was the radio operator on a coastal tanker back in the twenties. He was able to acquire an old 1912 spark gap signal receiver when they were replaced with the tube type equipment, and it is still in almost perfect condition. 73 WG5X

 

Spark Gap Links

• 5YM's Spark Gap Transmitter
• A Brief HISTORY of SPARK - GAP by W1FJI
• Explore the American Museum of Radio & Electricity
• John Jenkins Spark Museum
• Marconi 1 1/2 kw quenched spark gap transmitter
• Marconi emergency quenched spark gap transmitter of the Type 335
• Spark Gap Transmitter by HARRY, Lunda, Sweden

 

Old Issues

2007 January February March April May June - July August September October November December	2006 January April June July August September October November December	2005 January February March April May June July August September October November December
2004 January February March April May June July August September October November December	2003 January February March April May June July September October - November December	2002 January February March - April May June July - August September October - November December
2001 January February March April May June July August September October November December	2000 January February March April May June - July August September October - November December	1999 January February March April May June July August September October November December
1998 March April May June July August September October November December	1997 January February March April May June September October November December	1996 June July August September October November-December

Back to MARC's Page

 

Last updated 03/10/2008