10 Jan 19

At night, solar radiation ceases and the free electrons recombine with their host molecules. The D-layer completely disappears and offers no signal loss. The E/F layers merge into a single layer, but remain reflective to HF signals.

However, this combined layer has a lower electron density than daytime levels, lowering the MUF. Astronomers call these ionization layers plasma layers and the lowest frequency that escapes into space the plasma frequency, fp. QRPers look at it just opposite – what is the highest frequency that does not escape into space?

We call this the maximum usable frequency or MUF. In reality, the MUF and plasma frequency are exactly the same.

7 Jan 19

Built by AT&T in Houlton Maine, this array of 4 phased beverage antennas was used for the first transatlantic phone system which began operation on the 7th of January 1927… The first conversation took place betweenWalter S Gifford, the president of AT&T, in NY, and Sir Evelyn Murray, the Secretary of the General Post Office, which managed the British telephone system at the time.

History Channel… The First Transatlantic Conversation (1 minute commercial before it starts) 

Wikipedia … Good source for Beverage antenna history and more….

EDN Network … Good article with links on the first transatlantic phone call 

24 Nov 18

Rudolph Hell, born 19 December 1901,  died 11 March 2002 was a German Inventor and electrical engineer. In 1925 he began inventing the Hellschriber which at the time ran through cable lines and is the predecessor to the Dot Matrix printer. In 1929 he received a patent for the Hellschriber system. 

1930’s is when it began being used for news wire services and continued up to the 1980’s. The Germans used it sometimes during WW2 in conjunction with the German Enigma machine for land based communications.


300px-Hellschreiber-machine-at-bletchley-parkFor More

Rudolph Hell … (Click Here)

Hellschriber … (Click Here)

QST Article  April 1999 … (Click Here)

28 Nov 18

In the United States and Canada, the plural term candelabra is a nickname for radio masts and towers with multiple transmission antennas. Baltimore’s TV stations, WMAR-TV, WBAL-TV, and WJZ-TV in 1959 built the world’s first three-antenna candelabra tower, 730 feet tall. Other examples include the Mount Royal Candelabra in Montreal, the KXTV/KOVR/KCRA Tower, KSMO Candelabra Tower, KMBC/KCWECandelabra Tower, the Madison Community Candelabra Tower in Madison, and Sutro Tower in San Francisco.

Source was Wikipedia, you can follow it from the link at the bottom of my post on 26 Nov 18