The Birmingham age-herald., 1922-08-20
SUBWATER LOOP ATHENA GAN GUT
 DOWN THE STATIC |
New System of Buried Loop eaa Gives Very Successful
 Results

radios outstanding problem-hoW To limit static interference in receiv- ing-has been made, 1t has just been disclosed through a series of experi- ments conducted by the radio service of the post office department. The results are declared by government radio experts to have proven that the aerial antenna for receiving is about to be placed among the relics of early radio history.
 "Statis." the one big fly in the ointment of all operators, is about to succumb before a comparatively simple device, an underwater loop, according to the predictions, which are based upon report just made to James c. Edgerton. superinten- dent of the post office radio service, by his station at Bryan, O. Compar- ative tests were made there under the direction of MT. J. V. Maresca. who was formerly connected with the Radio corporation. with three antenna systems, the straight aerial, which was the same as Is used for transmitting, the pole loop and the underwater loop. The report shows the approximate signal statis ratio of the three systems used at Bryan are as follows:
 -Ratio-
 Antenna. Signals. Static. l straight aerial .......
 pole loop ..,.......r.. 2 underwater loop ....
 Single Turn Loop
 'This under water loop. which has been in use only two weeks, but Is now being used regularly in prefer ence, of course. to any other antenna for the routine work of the station, is a single turn, horizontal, 140xl90 feet, with the lead-in to the station 90 feet long. The wire used Is No 12, rubber covered. The wire is placed approximately three feet un- der water and the leads from the pond to the station are buried in the ground about six inches deep. From the ground to the receiving set the leads are fncased in lead sheathing, the sheathing being grounded.
 "The following description of the tests conducted has been made by flames C. Edgerton, superintendent of the radio section:
 "The air mail radio section has eliminated the use of regular trans hitting antenna for receiving pur- poses altogether, as it has been found that the severe static eondi- lions prevalent, especially in the middle west, made receiving impos- sible. Very good receiving condl- tions with favorable signal static radio has been obtained, however through the use of three different methods of receiving, which are se- leeted to conform to local conditions. They are, first large verticle outside multiple turn loops; second, ana last ly underground antennaes.
 d, ''The best results are obtained with. the underground antennas when in q a straight away of 1000 feet. The hori- zontal buried loop is more or less of new departure and has been very Successful when well insulated and hurled in water or very damp earth. Lightning Effect Reduced
 .1n actual use well constructed under ground antennae, such as IS used in the majority of the 10 sta lions in the air mail circuit the re- suits are rather unusual. Communi- cation has been carried on m tne middle west between ar nali s,d tions when lightning was actuaiiy strjlxfns nearby. As a matter or fact' If has been possible to carry on com i,nrnication when the currents Tn duced in the antennae from nearpy ilirhtning discharges blew out 'he arc. Receiving on an ordinary an tennae would have, of course been ainpossible long before the storm ''Yeached the vicinity.
 , M Inasmuch as the post ofiiee SUI .,t,ons. which have the primary duty ..ss controlling the transcontinental risir mail service flyers, have not been raahle to transmit through moderate .nliohtning it has been necessary to adevise a method of reception through Hguch condition and not burn up ,ethe receiving sets.
 ,un Each one of the 12 receiving sta ,atfons is equipped with five klio- Watt arc transmitter. During the Winter time and approximately eight amonths out of the year stations as efar west as Salt Lake City are able gro intercept traffic transmitted by ,,,WWX, the Washington station. uIi likewise, during the absence of local iinterference, this station is able to copy as far west as Salt Lake and has intercepted Elko, New, all during the daytime.
 at Summer Range Low
 ll, However, during July, August and aSeptember the receiving range Is cut Ndown so that the maximum working range of wireless as a rule is with Bryan, Ohio, a distance of 400 miles during the daytime. During the months of July. August and Septem- Der static interference starts in about tiluOOnllIlt anu COHlliutS uNlll gen erally or, T o'clock the next morn ling.
 The aim of this development is to .lenable all stations to work through out the 24 hours.
 The same form of loop as the Bryan Hoop has been used at Hazlehurst. L.. HI, with considerable success That lwire however, was not buried under lwater. but was used as a ground loop. Inasrnuch as this Is horizontal form iof loop and is probably not as direc- Ittional as the vertical loops it enables stations away from the center of in Interference, such as we have near New York and San Francisco, to get the i.traffic through. It must be under istood that the department realizes that there has been developed re- illreceiving systems by such companies las the Radio Corporation. which elim- llIinate static to a great degree, but 1.-the air stations work with other sta .iifions at variety of wave lenghts iil1hat make 1t necessary to have a