Radio age (Jan-Dec 1925)

44 RADIO AGE for April, 1925 The Magazine of the Hour A Novel Radio Frequency Receiver Chauncy De Pew, of Alpena, Mich., has given us an interesting circuit, that employs radio frequency amplification in quite a novel manner. A variometer and condenser are used to tune the circuit. His letter is as follows: RADIO AGE, Gentlemen: For the past year I have been using the circuit described herein, and have had very good results with it. I have never seen it in print, and for that reason I do not think that there are many of the fans who have ever heard of it. It was originally given to me by an "old time" radio man, and as he still uses it I think it might be worth while to pass it along to the readers of the Dial Twisters' columns. The apparatus needed for construction, can usually be found in any radio experimenter's workshop. The set is very easy to construct and once you get "the hang" of operating it, you will find that it is a regular DX receiver. Many of the so-called DX circuits can in no manner compare with my little two-tube "nameless." The variometer is of the series type, and should be of the best kind obtainable. The radio frequency transformer consists of two honey-comb coils, the primary side being a coil having fifty turns, and secondary having but thirty-five turns. Across the primary coil is a condenser having a capacity of .0005 mfd. The coils can be mounted on a double coil mounting, so the coupling between them can be varied until the best setting has been found. There is not much more to be said regarding this circuit, except that I might tell you of some of the distant stations that I receive with quite a little bit of regularity. WOC, KDKA, KFKX, KTHS, KYW, WGN, WBAP, and WBS are stations that I can get at will. On WOC, KDKA, or KFKX, I can rest the headset on the table and hear the stations plainly at a distance of fifteen feet. Yours verv turly, CHAUNCEY DE PEW Alpena, Mich. The same receiver as described by Mr. De Pew should be quite selective, and he seems to be a little bit proud and a little bashful about disclosing his DX list. Perhaps the circuit is as efficient as he says. There is no doubt but what the set can be constructed easily, and for that reason we are going to pass it along to some of our brothers who "crave" DX. William Vreeland, of 67 Union street, Montclair, N. J., wishes us to pass this circuit along to the readers of the D. T. columns. He has found this set very effective, ami would like to hear from any of you who will experiment with it. His letter is as follows: RADIO AGE, Gentlemen: I am sending you a diagram of a small receiver which I find to have good tone, volume and DX qualities. You will also find enclosed a list of stations that I heard one evening from 9:00 p. m. to 10:15 p. m. They are as follows: WDAR, WIP, WTAS, KDKA, WSAI, WEBH, WREO, WPO, WGY, WMH, WBZ, WJAR, WLS, WEBH, WEAN, KFKX, WEAO, WSAD, WQAM, WRK, WOAW, KYW, KSD, KFKB, and WOC. Not so bad for an hour and a quarter on a one tube set. I wish you would Ik "4 /ff o B ,34.9 +■ O 6 Chauncey De Pew's Radio Frequency Receiver, RADIO ACE passes it on to you. [iven to him by an "old timer," and publish this circuit for the benefit of the fans who want a sensitive yet low priced set. William Vreeland. 67 Union Street, Montclair, N. J. Mr. Vreeland calls his circuit the "Audiodyne." The tuning inductance is wound on a four inch tube, the primary consists of ten turns of No. 22 D. C. C. wire and the secondary consists of fifty turns of the same size wire. A variable vernier condenser is placed across the secondary. The grid condenser should have a capacity of .00025 and the grid leak will be about two megohms. A variometer is placed in the plate circuit for regeneration. Any of you fellows who want a good, sensitive circuit and do not care to "sink" a lot of money in new apparatus are advised to try the circuit contributed bv Bill. Another one of our contributors this month is Ernest H. Jones of 315 Wheeling Ave., Muncie, Ind. The outfit he describes is a simple one, and from all reports a good one. Using this circuit he has heard the following stations: WOS, WBZ, WDAF, WHB, WOAW, WAHG, WGY, WBAP, WEAF, WMC, WCCO, WGR, KFDM, KFNF, WOQ, WJY, KFNG, WSB, WJZ, WNAC, KGO, WOR, WOC, WJAR, CNRO, WJAD, WCAL, WLBL, WBBF, WAAW, WEEI, KFI, WCK, WFAA, WIP, KSD, KFKX, CKAC, KFKB, CFCA, WHAR, WHAA, WCAY, WCAP, WHO, and WNYC. Here is his letter: RADIO AGE. Gentlemen: For a long time I have been reading your magazine, or, our magazine, since it is for all radio fans. I enjoy reading your technical articles and the D. T. section. I have been afraid to send in a list of stations heard, but I can't hold out on the fans any longer. I am using a single tube set which I made myself. It is simplicity itself, "radiofied." I am enclosing a sketch of the circuit for the benefit of anyone who wants a receiver that always works and works well. Almost all kinds of apparatus will do, as long as they are electrically sound. However, any fan should not hesitate to use the best he can get. I have found that this policy always pays, in quantity and quality of reception. I have built several sets for my friends, using this circuit. One of them "copped" a prize offered for the best list of stations heard. The prize was a pair of well-known "phones." If any of the fans who try this circuit fail to make it work, I wish they would let me know about it. I would be glad to answer my letters relative to it. However, I might add that I do not expect to hear from any one from this cause. I would like to say that in more than two years of experimenting with tuning units and single-tube sets, I have never found one better than this one. Very truly yours, ERNEST H.'JONES. 315 Wheeling Ave., Muncie, Ind. Well, fellows, that's his letter, and it seems as though Ernest is mighty proud of his circuit. As he states, the circuit is simplicity itself; anyone can see that when he consults the wiring diagram. The tuning coil is wound on a tube four inches in diameter and consists of eighty turns of number twenty-two, D. C. C. wire, tapped at the 15th, 32nd, 45th, 60th, and 80th turns. The wiring diagram is self-explanatory and for that reason