9 months ago

Electronics-World-1959-05 Argos Model DSE -1 KLH Model Six Stephens' "Stereodot" Frazier " Stereorama II" bass that is supposed to be there, so stereo should have just plain, good bass. Some of the earlier small bass units relied on harmonic generation to give a "false bass" -like the car radio bass, but more modern approaches have resulted in units that do give real bass from much smaller units than hitherto was believed possible. Some manufacturers claim that trying to get big bass from small speakers is defying "the laws of physics." I think it would be more accurate to say that some designs have found some "loopholes" in these "laws." But do satisfy yourself that the unit you buy does give genuine, clean bass that is adequate for the room in which you will play it and working from the amplifier you will use. Two Identical Units So much for the "system" approaches, some of which come pretty much "ready- made" while others give plenty of scope for experimentation. But another approach that offers wide appeal for two reasons is of the two - identical -unit variety. This may come either as separate loudspeakers which connect to an I ST CO REO 0"0M1 Es>i?:i:l IA, CONSOLE IyREE"{nl I STEREO STEREO CONf0.1 NTENNA, So TE REO m a Fig. 9. Arrangements used In Columbia consoles: (A) and (B) use 2 full -range speakers; (C) combines lows in central woofer and mid -range and highs to external units. Fig. 10. Basic arrangement used in Ranger - Lansing "Paragon and "Metregon" units. I I ANU W MIOOLE CONNECTS sT THANT0S CWC "T TO IOTw Mhe[RS CORNER HORNS FOR LEFT ND RIGHT Fig. 11. Klipsch's recommended setup, with 2 corner horns and "phantomed" center unit. Fig. 12. Method of getting good horizontal distribution and avoiding unnecessary vertical spread with extended -range units. 44 RADIATION COMIWES IN HORIZONTAL PLANE RUT CANCELS M uR AND DOWN DIRECTIONS 10A5NE0 ARROWS, MAKER Columbia Electro -Voice Jensen Klipsch Stephens University MODEL 360,626,637 Stereon Stereo Director Heresy Stereodot Stereoflex BRIEF DESCRIPTION Central unit for mixed lows, part of console; small side units for stereo highs, above 250 cps; jack arrangement, see text. Add -on unit consisting of mid -range and tweeter speakers working above 300 cps. Bass in both channels handled by low- frequency speaker system. Ducted -port enclosure for woofer. Mid -range and tweeter units are swivel- mounted to permit varying of directivity. Corner horns with sealed back enclosure for center fill, phantom- connected to amplifiers. Central unit for mixed lows and controlled mixture of highs for center fill; small side units for stereo effect, above about 400 cps. Add -on unit consisting of mid -range and tweeter speakers working above 150 cps. Bass in both channels handled by dual voice - coil woofer. Table 2. Here are some of the special stereo systems with brief descriptions. conduct some careful listening tests of your own. Stereo Bass In going over different systems -or for that matter, individual speakers too -you will find a further area of conflict lies in the kind of unit used to provide bass response. Paul Klipsch won't hear of anything but a corner horn, except for the center fill. Other manufacturers maintain - as almost anyone would have until a year or so ago -that a speaker must be big to get good bass. Edgar Villchur (of Acoustic Research) says that there is merit in a low- efficiency and small bass system. So what kind of bass is good for stereo? As was explained in Part 1, pure bass is not materially stereophonic in any ordinary sized living room. But music is deficient without equipment cabinet or with the equipment included in one ensemble with a companion speaker to match. In achieving stereo, both offer similar prospects. Also some systems come as a matching set of three which can stand close together thus simulating the one -piece system or be spaced farther out if this is found necessary in a particular listening room. Directivity But we now get into another difference over which to choose: directional or diffuse radiating (omnidirectional) type loudspeakers? On this score most speaker manufacturers belong to one school or the other. The omnidirectional school uses diffuse radiators so that sound exclusively from one unit will be identified with it -wherever you are in the room. Cor- (Continued on page 126) ELECTRONICS WORLD TV Shop Uses Two -Way Radio From his shop, Devin can advise on home repairs, re -route vehicles economically, or approve purchases of used sets. Field technician Jerry LeCompte can check on late calls for fast service, get shop advice, or OK's on old sets. Many dealers are becoming interested in selling or maintaining two -way mobile radio. Here's one who uses it himself --to his advantage and profit! EDITOR'S NOTE : With everybody (including ELECTRONICS WORLD) talking about service opportunities in two-way to o b ile radio, opened up by the virtually unlimited applications in all businesses, let's not a rerlook o key possibility. A ser r ice business con benefit as much from this medium as can any endeavor using vehicles.' In addition, what could help you push two -tory sales and srrrice more than a Tiring example?' Incidentally. don't con) use the Rusin esa Service with operation on Ihr Citi :ens Rand. which is permissible without type -a pp rond equipment. For information on the lolirr, ,sec "('ilions Radio Faces the Futue," Sae nt ber 1955, and " /mild This Cit i_ens Rand Transceiver;' March 1959. THE NEW Business Radio Service is a natural for TV sales and repair organizations seeking an efficient 2- way radio system. Just ask Lee Devin, owner of Lee Defiles TV, 929 N. W. 10th Ave., Oklahoma City, Oklahoma. Devin was one of the first Oklahoma businessmen of any kind to apply for a license in this service: his Motorola system was installed shortly after the Federal Communications Commission opened the service on August 1, 1958. His initial system consisted of a 25- watt a.c. utility base station, an "Isoplane" antenna on a 50 -foot telescoping TV mast, and two 25 -watt mobile units. The two mobile radiophones were originally installed in Devin's car and the service station wagon. When he traded in his auto, he had a new 60 -watt, transistor -powered mobile unit May, 1959 installed in the new car and the original set put in the company's pickup truck. The original system provides 10 -15 miles range, sufficient to cover most of Oklahoma City's metropolitan area. In order to cover the fringe areas beyond this, Devin plans to erect a 100 -foot tower and a high -gain antenna. Besides operating a widespread TV repair service, Devin is heavily engaged in buying, renovating, and reselling used TV receivers. He finds two -way radio is most useful in both his sales and service activities. Dispatching service calls to technicians in the field is a "natural." By relaying new calls to the men in the field, efficiency and productivity can be increased greatly, since waste trips back to the office are eliminated. Devin feels his three -man organization should be able to handle 10 per -cent more calls through radio. This means increased income and also lower operating costs, since gasoline and vehicle wear are cut through the elimination of waste mileage. On puzzling service calls, the technician can also use the radio to get fast assistance from the shop. This avoids using the customer's phone, often a cause of embarrassment. Devin reports that an uncommonly competitive situation exists in the used receiver market in Oklahoma City. Oftentimes when a family wishes to get rid of a set, it will call three or four companies. Then bidding for the receiver (if it's in reasonably good condition) takes it out of the "good buy" category. Devin says that a 2 -way radio call to a man in the field enables him to "beat the crowd" to the seller's home and thus often snap up the set at a price that leaves room for a good, fair profit. One of Devin's men, Jerry LeCompte, says the radio is very helpful to him in passing certain decisions on to Devin. He says, "I really appreciate not having to stick my neck out on bids when I appraise a set. With radio, I can ask Lee how high I can go." The same situation exists in set sales at the store when Devin is out. A prospect offers a set price for a receiver. Devin can be contacted immediately to say "yes" or "no" to the deal. Fast action like this saves many sales that might otherwise be lost if the prospect were told, "I'll let you know this afternoon." In summary, Devin says that his new 2 -way radio system, made really effective through the Business Service, provides the means for tight, efficient operation of all phases of the TV sales - service business. -- 45

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