Radio broadcast .. (1922-30)

55,000 Miles on a Dry-Cell Tube ANOTHER BEGINNER'S STORY By HARDING GOW WE SPENT last summer on Orcas Island of the San Juan group up in the northwest corner of the United States. Of course we took a crystal set along, but as that limited us to one station it naturally followed that we had to have a tube set. At that time I did not know the difference between a variometer and a grid leak, so 1 came down to the Seattle Radio Show in search of information and material. I selected a tube which had just been put on the market and which required only one dry cell for the A battery, inasmuch as there was no way of charging storage batteries at East Sound, and decided on spiderweb coils because I had obtained good results with them on a crystal set, and also because there seemed to be practically no data obtainable on them and I was curious to try out their possibilities. I may add that I have never regretted the choice. In first assembling my apparatus, I followed the conventional custom of compactness and got the condensers too close together. 1 tried shields between them and also a panel shield for body capacity but this seemed to me to reduce materially the signal strength, and in working distant stations on one tube, the tiny bit of energy absorbed by the shields may decide whether the voice of that fellow 1,800 miles away comes in clearly or as a confused murmur. So I pulled the set to pieces (a frequent occupation at first) and spaced the condensers well apart in a larger cabinet, mounting the coils on the ends of four-inch brass rods to get them away from the condensers. Then I began to get results. On Standardizing Radio Equipment Commander Stanford C. Hooper, U.S.N., is the man who suggested the formation of an American organization to maintain our position in radio communication. The Radio Corporation of America is the result. Commander Hooper has entire charge of the Navy's intricate radio communication system and is head of the Radio Division of the Bureau of Steam Engineering. He has some very constructive views on standardizing equipment and is preparing for RADIO BROADCAST an article on this important subject, which will appear in the March number. — THE EDITOR. The final assembly is shown in the photograph, which 1 am free to admit could not be called handsome, but the way it reached out and gathered in the distant stations was a constant surprise and delight. The hook-up is the ordinary three-circuit regenerative type except that I used a variable condenser across the B battery and phones, and another across the tickler coil, and find them of great value in tuning the plate circuit without changing the tickler coupling, and they also bring out the tone of both voice and music. The secondary condenser is sensitive to body capacity, but with the type of vernier handle shown it is possible to avoid annoyance from this cause. For the values given, the primary and secondary condensers work best on about the same reading. I usually set them at 35° to 40° and pick up the stations by varying the primary coupling, maximum signals being obtained by adjustment of the plate condensers and the primary vernier. The set is extremely selective. I think the most surprising feature to my wife was that she could shift from Fort Worth, Texas, to Calgary, Alberta, by moving the primary coil perhaps an inch! From six to ten stations could be tuned in and out in this way without resetting the condensers, and I frequently was able to pick up both ends of test conversations between stations. One night I heard Calgary, CFCN, calling Wallace, Idaho, KFCC. I listened to them for some time when KFAY at Medford, Ore., came in, KDZZ at Everett, KMO at Tacoma, and yXI at Portland, all by shifting the primary coil, and I seemed to hear them better