Page:February 1916 QST.djvu/6

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FEBRUARY, 1916
QST
23

primary. This means a fairly large degree of coupling between the primary and secondary of the oscillation transformer. Too close coupling will make your decrement high and this is hardly desirable. To make the secondary circuit absorb the greatest amount of energy, you must make its wave length equal to the wave length of the primary circuit. You see, it's a very neat little arrangement. The primary circuit is nothing but a condenser, gap, and inductance. The secondary circuit is very similar to the primary; you have the secondary inductance and the condenser effect is obtained between the aerial and ground as shown by the dotted line in Fig. 2.



“Now I can probably begin to argue about the arrangement of your apparatus. You can see how important it is to have the leads short that you may not lose energy. By short, I mean about a foot for each connector. In your case, the leads are probably five feet long on an average. If you had placed your oscillation transformer, gap, and condenser close together, it would have been possible to cut the length of the connections down to two feet. Suppose you had placed the oscillation transformer directly above the condenser and near the side of the condenser there would be room for the rotary.”

“Well if I do that, I'll have that noisy thing up in my room. Besides, it will litter up my table,” objected the listener.

"Well, of course, if you are fixing up your set to look at, have your own way,

but if you want to talk with somebody, take my advice and arrange your apparatus not for looks but for short leads. Try it in several positions and find out which works best. Then you should connect it with wire of respectable size; perhaps, No. 8 instead of 18. Copper ribbon is very good, but stranded wire is better. As to the noise, why don’t you put your rotary in a box, or buy some kind of a quenched gap?

All these things which I have suggested in regard to your sending apparatus apply to the receiver. In your case, the receiving set seems fairly efficient as you have purchased it in a complete unit. Just let me give you a bit of general advice concerning your operating table. You work your station right handed. I am also right-handed and I have always found it a good plan to have the receiving apparatus on the left with the aerial switch, then the key and finally the sending. That gives you a chance to change quickly from sending to receiving. You will find it very convenient.

“I suppose we might even improve your aerial,” I suggested. “You might raise it a few feet to clear some general obstruction, and again you might help things a great deal by straightening your lead-in and using a large wire or a better ground. I'm sorry that it's so dark tonight, but some time I’l1 come out earlier and we can look over your aerial. For the time being, I guess you will be busy enough looking over your set and trying to get the right arrangement. As it is now, I don't suppose you are sending ten miles, but fix it up and you will be able to talk with me.”

Then, we had dinner and after receiving his many thanks and numerous blessings, I started out on my mile walk through the one horse town and seven inches of snow. I was convinced that this visit had been a help to my friend. If I only had the time, I should like to visit several hundred other amateur stations which need improvement.

MORAL: Arrange your apparatus in an efficient way; make the leads short; use copper ribbon, or stranded wire; work for the best combination.

HONOLULU STATION GETS WAR DISPATCH FROM NAUEN, PRUSSIA.

A New World's Record 9,000 Miles.

Honolulu, Nov. 29th.―A new world’s record was made last night, when an operator of the Federal Wireless Telegraph Company picked up signals transmitted from Nauen, Prussia, to Tuckerton, N. J., a distance of approximately 9,000 miles. The German operator was sending war dispatches and the signals were very clear in Honolulu. This remarkable transmission

about reaches the limit on the earth as when 12,000 miles are covered no one can tell from which direction the messages come. That is, we can only receive messages from half way around the earth. It is peculiar to note that many of the long distance records have been made at Honolulu. The best previous performance in long distance wireless communication was 6,000 miles.