NAEB Engineering Newsletter (Mar 1958)

by a new firm, I.T.A., Industrial Transmitters and Antennas, 7327-A West Chester Pike, Upper Darby, Penna. Their new line of fm transmitters, designed especially for the 88-108 me educational band, con¬ sists of 10, 75, 250 and 500 watt transmitters. The latter two transmitters have been type accepted by the FCC and the 10 and 75 watt models are now being processed for approval. With the number of fm stations on the air grow¬ ing daily, and with no more fm channels available in large population centers, educational institutions would do well to take another look at fm broadcas¬ ting. Pressure is certain to develop for the FCC to assign the unused channels for commercial use, once the available commercial assignments are occupied. For years Gates Radio Company of Quincy, Illinois has been the sole manufacturer of fm broadcast equipment. The RCA announcement of a new fm line and now the I.T.A. announcement points up the fact that fm is again on the upswing. The announce¬ ments also emphasize the need for educational in¬ terests to get busy and occupy these reserved chan¬ nels while they are so easily available. TV TECHNICAL TIPS (February) — Cecil S. Bidlack On Jan. 15, I had the privilege of attending a dem¬ onstration of the new RCA color video tape re¬ corder in Camden, N. J. More than 100 broadcasters and engineers attended the afternoon demonstration including Fred Remley and Larry Griewski of the University of Michigan, Dr. W. J. Kessler of the Uni¬ versity of Florida, Cy Braum of JCET and the writer. We saw Art Hungerford in the group attending the morning demonstration and there may have been other ETV representatives we missed seeing. We were very much impressed by the performance of the equipment. Some observers thought the quality of the recordings as good as live pick up. Sections of the Perry Como Show of the previous Saturday, and a portion of the same day’s Howard Miller Show were presented in color as well as a specimen of black and white recording. Tape dropouts were in evidence on both the monochrome and color record¬ ings and were especially noticeable in the color re¬ cordings since they produced white noise flashes. The RCA system is similar to Ampex in that tape width, tape speed and the tape itself are the same. RCA uses a revolving head mechanism holding four heads, although head rotational speed differs slightly from the 1440 rpm used by Ampex. At present tapes are not interchangeable between machines, however this feature will be available on production models. RCA and Ampex are discussing mutual standards so that eventually universal interchangeability will be possible. RCA equipment is entirely rack mounted while Ampex uses a console-mounted transport mech¬ anism with part of the equipment rack mounted. The RCA equipment also incorporates an erase head while Ampex tapes must be bulk erased. RCA has an addi¬ tional independent audio cue channel so that special operative instructions can be recorded along with picture information. A price of $63,000 has been announced for the RCA color recorder and $49,500 for monochrome equipment. Production models are expected to be available toward the end of 1958 with seven proto¬ type models to be built and put in service prior to the production run. Monochrome equipment contained in five racks, can be converted to color by the addi¬ tion of one rack of color processing equipment. The equipment requires 6 kw of 60 cycle single-phase power for operation. ***** Ampex, too, is making an accessory kit to con¬ vert its monochrome video tape recorder to color. It consists of an additional rack of equipment costing $29,000 for the prototype units. The first of these has been promised for June delivery to WGN-TV, Chicago. A substantial reduction in price is expected once this equipment is on a production basis. ***** Damage estimated at $75,000 was caused by a fire Jan. 9 in Swain Hall, which housed the studios of WUNC-TV and WUNC-FM in Chapel Hill, N. C. It is believed that the fire was the work of an arsonist as seven fires occurred on the campus that day. Spun glass used in the sound treatment of the studio area prevented the fire from spreading, thus saving the building from complete destruction. The radio area suffered only smoke and water damage. It is expected that the radio studio will be ready for occupancy before Feb. 1. Much video equipment was saved. TV programming was moved temporarily to the Raleigh studios. However, on Jan. 20 some programming was resumed from Chapel Hill by using the remote bus as a studio. It is ex¬ pected that it will take at least six weeks before the damaged studios and offices are ready for occupancy. ***** General Electric has announced that 50 TV sta¬ tions are now equipped with “1-0 guards” the wobbu- lating device designed to improve the useful service obtained from image orthicon camera tubes. Among the ETV stations which are using this equipment are MARCH 1958