9 March 19

As early as 1839, the German mathematician and physicist Carl Friedrich Gauss postulated that an electrically conducting region of the atmosphere could account for observed variations of Earth’s magnetic field.

In 1926, Scottish physicist Robert Watson-Watt introduced the term ionosphere in a letter published only in 1969 in Nature:

We have in quite recent years seen the universal adoption of the term ‘stratosphere’..and..the companion term ‘troposphere’… The term ‘ionosphere’, for the region in which the main characteristic is large scale ionisation with considerable mean free paths, appears appropriate as an addition to this series.

The ionosphere is a shell of electrons and electrically charged atoms and molecules that surrounds the Earth, stretching from a height of about 50 km (31 mi) to more than 1,000 km (620 mi). It exists primarily due to ultraviolet radiation from the Sun.

More at Wikipedia

8 March 19

The 33-centimeter or 900 MHz band is a portion of the UHF radio spectrum internationally allocated to amateur radio on a secondary basis. It ranges from 902 to 928 MHz and is unique to ITU Region 2.[ It is primarily used for very local communications as opposed to bands lower in frequency. However, very high antennas with high gain have shown 33 centimeters can provide good long range communications almost equal to systems on lower frequencies such as the 70 centimeter band. The band is also used by industrial, scientific, and medical (ISM) equipment, as well as low powered unlicensed devices. Amateur stations must accept harmful interference caused by ISM users

More can be found at Wikipedia

33 Centimeters (902-928 MHz)

Frequency RangeMode
Functional Use
902.000-902.075FM / otherincluding DV Or CW/SSBRepeater inputs 25 MHz split paired with those in 927.000-927.075 or Weak signal12.5 kHzchannel spacing Note 2)
902.075-902.100CW/SSBWeak signal 
902.100                    CW/SSBWeak signal callingRegional option
902.100-902.125CW/SSBWeak signal 
902.125-903.000FM/otherincluding DVRepeater inputs 25 MHz split paired with those in 927.1250-928.000012.5 kHzchannel spacing
903.000-903.100CW/SSBBeacons and weak signal 
903.100CW/SSBWeak signal callingRegional option
903.100-903.400CW/SSBWeak signal 
903.400-909.000Mixed modesMixed operations including control links 
909.000-915.000Analog/digitalBroadband multimediaincluding ATV, DATV and SSNotes 3) 4)
915.000-921.000Analog/digitalBroadband multimedia including ATV, DATV and SSNotes 3) 4)
921.000-927.000Analog/digitalBroadband multimediaincluding ATV, DATV and SSNotes 3) 4)
927.000-927.075FM / otherincluding DVRepeater outputs 25 MHz split paired with those in 902.0000-902.075012.5 kHzchannel spacing
927.075-927.125FM / otherincluding DVSimplex 
927.125-928.000FM / otherincluding DVRepeater outputs 25 MHz splitpaired with those in 902.125-903.00012.5 kHzchannelspacingNotes 5) 6)

1) Significant regional variations in both current band utilization and the intensityand frequency distribution of noise sources preclude one plan that is suitable for all parts of the country.  These variations will require many regional frequencycoordinators to maintain band plans that differ in some respects from any national plan.  As with all band plans, locally coordinated plans always take precedence over any general recommendations such as a national band plan.

2) May be used for either repeater inputs or weak-signal as regional needs dictate

3) Division into channels and/or separation of uses within these segments may be done regionally based on needs and usage, such as for 2 MHz-wide digital TV.

4) These segments may also be designated regionally to accommodate alternative repeater splits.

5) Simplex FM calling frequency 927.500 or regionally selected alternative.

6) Additional FM simplex frequencies may be designated regionally.

6 March 19

The Boy Scouts of America’s “Radio” Merit Badge… The Boy Scouts of America holds a Jamboree on the Air once a year which the ARRL is involved with at several locations, this event is also known as “JOTA”. Many Ham’s volunteer to be counselors to help scouts in obtaining this Merit Badge and promote Amateur Radio.

K2BSA Amateur Radio Association is all about scouting and amateur radio communications…. (Click Here)


5 March 19

RTTY dates back to the mid 1800’s but was not transmitted over radio till 1922 by the US Navy between an aircraft and a ground station. Later that year RCA transmitted between a radio station in Chatham Massachusetts and a ship the R.M.S. Majestic… For more (Click Here)

The typical RTTY baud rate is 45.5 on amateur radio. For more history on Baudot (Click Here)

2 March 19

The USAA-CQ put on by CQ magazine is an ongoing world wide challenge for USA Counties. The rules and regulations can be found (Here). This challenge is ongoing and in the regulations you will find a link to the acceptable electronic logging program submissions. This contest is open to all Amateur Radio Operators. CQ Magazine has a few more Contests, (Click Here For The Calendar).

Source: CQ Magazine

28 Feb 19

Model J Echophone

The Echophone

Article and pictures are from The Perham Collections site.

The Radio Shop was founded by Arthur E. Bessey, Jr., a well-known amateur radio operator, sometime before May 1920. Bessey was already in business with his father in Sunnyvale, who had an innovative patent for incubators and brooders for poultry farmers. Bessey and his partners started their business in these poultry buildings, soon opening a sales location in downtown San Jose’s Bank of Italy building.

Patterning their parts after Colin Kennedy’s and claiming to have an official license from patent-holder Edwin Armstrong, they advertised a matching detector and two-step amplifier, and a three-circuit tuner. In 1922, as the radio boom hit the Bay Area, Bessey also started Sunnyvale’s first radio station, KJJ.

Initially, The Radio Shop built sets to order for other companies or distributors, then began to make simple sets under their own trade names, including the Echophone. Echophone eventually was sold to William J. Halligan, and became the basis for Hallicrafters.

The Perham Collection of Early Electronics includes two models of the Echophone:

24 Feb 19

Jamboree-on-the-Air, or JOTA, is the largest Scouting event in the world. It is held annually the third full weekend in October. JOTA uses amateur radio to link Scouts and hams around the world, around the nation, and in your own community. This jamboree requires no travel, other than to a nearby amateur radio operator’s ham shack. Many times you can find the hams will come to you by setting up a station at your Scout camporee, at the park down the block, or perhaps at a ham shack already set up at your council’s camp. … JOTA Website

Radio Merit Badge Requirements


23 Feb 19

The trembler coil was a device called a Ruhmkorff or induction coil, widely used in the 19th century.  It combines two magnetic devices on the same iron-cored solenoid. The first is a transformer, used to transform low voltage electricity to a high voltage, suitable for an engine’s spark plug. Two coils of wire are wound around an iron core. The primary winding carries the low voltage battery current, and the secondary winding generates the high voltage for the spark plug. Attached to the end of the coil is an interrupter or trembler, a magnetically operated switch or relay, which repeatedly breaks the primary current to create flux changes in the transformer needed to produce high voltage.

Source: Wikipedia

The black box on the far side with 4 white wires and 4 yellow wires is the trembler (or ignition box)

22 Feb 19

Spark transmitters and the crystal receivers used to receive them were simple enough that they were widely built by hobbyists. During the first decades of the 20th century this exciting new high tech hobby attracted a growing community of “radio amateurs”, many of them teenage boys, who used their homebuilt sets recreationally to contact distant amateurs and chat with them by Morse code, and relay messages. Low-power amateur transmitters (“squeak boxes”) were often built with  ignition coils from early automobiles such as the Ford Model T …

The Images below are from Hamfesters Radio Club Chicago Ill …. W9AA

Source: Wikipedia