450 



and message practice, sending the words 

 most used in army practice first, then others 

 later as the operator becomes more pro- 

 ficient. 



Popular Science Monthly 



Relieving the Strains on an Aerial 

 Fastened to a Tree 



r |^HE amateur who has his aerials sus- 



between a house and a tree 



Careful Sending Is Essential 



In sending, strive always to make care- 

 fully and accurately timed dots, dashes and 

 spaces. Give particular attention to the 

 length of spaces between letters and 

 between words, as explained last month. 

 The receiving operator will not be able to 

 write down your letters correctly unless you 

 form them correctly, and without careful 

 sending many serious errors may result. In 

 calling, for example, be sure not to run the 

 call-signal letters together. Each time the 

 call is sent, pause for a word-space before 

 repeating it; otherwise instead of hearing 

 three well separated groups of letters 

 (KSW KSW KSW) the receiving operator 

 will get a jumble of nine letters (KSW 

 KSWKSW) and will not be able to tell 

 whether your call is KWS, WSK or SKW. 

 Similarly, keep the "de" well separated 

 from the call letters themselves, and the 

 "Attention" and "Finish" signals sharp and 

 distinct. Beware especially of making the 

 "Attention" signal sound like KA, or the 

 "Finish" signal like AR, by introducing an 

 extra dot space that should not be there 

 at all. 



When copying messages sent from an- 

 other station, even in the very beginning of 

 practice, wait till a single letter is com- 

 pleted and then write down that letter in 

 script. Never write out the dots and 

 dashes themselves; the letters * should be 

 transmitted to you sufficiently slowly, and 

 with enough space between each pair of 

 them, for you to write out the letters them- 

 selves. As you become more and more 

 skilled you will find it possible to carry an 

 - entire word or several words in your mind 

 before writing them down. To do this, 

 however, requires much practice and an 

 excellent familiarity with the Morse code. 

 The two-station practice method de- 

 scribed in this article, according to which 

 two students progress together, is far better 

 than studying for Morse reading by the use 

 of an automatic sending machine alone. 

 The ideal method, however, combines the 

 two. In the next article some further 

 points to be considered in operating will be 

 explained, together with an arrangement 

 for combining several stations and an 

 automatic sender on a practice buzzer 

 telegraph line. 



A tension spring in 

 the holding rope of 

 an aerial to relieve 

 strains on the wires 



- CHECK ROPE 



is often bothered by the breaking of 

 the wires. This is usually caused 

 by the tree swaying and pulling on 

 the aerial. The sudden strain so 

 exerted may be lessened by attach- 

 ing a spring to the aerial rope as 

 shown in the sketch. The spring stretches 

 when the strain becomes greater than the 

 wires will stand with safety. A check rope 

 should be attached to the spring so that if 

 the spring should accidently break the 

 aerial will not fall. — Paul L. Keating. 



An Inexpensive and Quickly Made 

 Detector 



HERE is a detector that can be built in 

 half an hour. It is simple to make 

 and easily adjusted. Upon a base 3 Yz in. 

 square, mount two spring connectors on 

 top of small blocks at the sides of the base, 

 as shown. The spring connectors may 

 be taken from an old dry-cell. A piece of 

 cat-whisker wire — mandolin E string — is 

 soldered to a small rod which is inserted in 

 the loop of one of the spring connectors. 

 The end of the rod is threaded and provided 



A detector made of scrap material mounted 

 on a wood base with wire connections beneath 



with a small insulating handle. The other 

 spring connector holds a piece of No. 14 

 copper wire, to which is soldered the cup 

 of an old dry-cell. — E. F. Jaspers. 



