As promised, here are the answers to yesterday’s quiz.  They appeared in the September 1961 issue of Radio-Electroincs.

These two quizzes appeared 60 years ago in the August 1961 issue of Radio Electronics.

We’re confident that most of our readers can figure them out. If not, we’ll post the answers tomorrow. If these look vaguely familiar, it’s probably because you’ve seen them here before. The first “black box” quiz is very similar to a circuit we showed previously from October 1956 QST. And the second one with resistors is almost identical (only the values have changed) to the one we previously showed from the January 1957 issue of QST.

The 1961 answers (which are similar to the 1956-57 answers) will appear here tomorrow.

FM stereo is 60 years old this year, and 60 years ago this month, the August 1961 issue of Radio Electronics carried an update on the status of FM stereo broadcasting. The format had been approved by the FCC on April 19, 1961, and the first station to start stereophonic broadcasting was GE-owned WGFM in Schenectady, NY, followed soon by Zenith’s WEFM in Chicago.

FM stations were free to start stereo service whenever they wanted, as long as they used approved equipment and gave the FCC 10 days’ notice. But the magazine noted that due to shortages of equipment, there would only be 20-25 stations on the air before the end of the year.

The magazine was advertising a few stereo receivers, and the article noted that there were two ways to get stereo. Some receivers had been constructed with multiplex inputs, and the manufacturers were tooling up to produce adapters. However, in most cases, it would be necessary to use an adapter from the same manufacturer.

Table model receivers were also soon available. The magazine predicted that FM stereo would not mean the end of monophonic FM. In fact, the additional demand for FM stereo would probably add interest to FM in general, to the benefit of stations broadcasting in mono.

Seventy-five years ago this month, the August 1946 issue of Radio Craft carried this simple circuit for a one-tube receiver. The circuit had been sent in to the magazine by one Robert Sherrington of High Prairie, Alberta, who noted that the circuit was very selective and would pull in locals with good volume on a loudspeaker. It employed a 117L7GT, half of which served as a rectifier, with the other half serving as a regenerative detector.

The designer of the circuit was almost certainly the same Robert Sherrington, who was 16 at the time he sent the circuit into the magazine. According to his 2015 obituary, he attended the Radio College of Canada in Toronto in 1949, and then owned a radio repair shop in High Prairie. He later moved to British Columbia, where was licensed as VE7DLX.

The magazine’s editor noted that the circuit, while unusual for the time, was not new, having been used in earlier receivers, including the Reinartz.

Sixty years ago this month, the August 1961 issue of Popular Electronics included this ad for an unusual combination from Hammarlund–the model HQ-105-TR.

The set was basically an HQ-100 receiver with one added feature: It included one additional tube for the CB transmitter. One CB crystal was included, and the receiver’s audio amplifier was used as the modulator.

The receiver covered the broadcast band up to 30 MHz, and had a bandspread calibrated for the ham bands. The ad noted that when the owner got the general class ham license, the transmitter could be easily retuned to the 10 meter band. In the meantime, the receiver could be used to copy W1AW code practice toward getting that license.

You can view the receiver in action in this video:

Interestingly, the mike connection is in the back, and there is no indication on the front panel that the unit also contains a transmitter.

Seventy years ago this month, the August 1951 issue of Radio Television Retailing reminded dealers that there was money to be made by selling clock radios, an item that readily sold to people in all income brackets.

The clock radio “looks just like any other table model set” to the customer, so some salesmanship was required. The salesman needed to be thoroughly familiar with the product, and emphasize the low price for something that could serve as a fine radio, an alarm clock, a timekeeper, and in many cases, an automatic outlet.

The magazine suggested that direct mail might be a profitable way to sell. Select customers could be sent a mailing offering a set on approval, and once in the home, the customer was very likely to keep the set.