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Ekco Radio Continued, More Of The PB189

The principle of the motor tuning operation is that when the desired button is depressed a circuit is made between the track on the circular disk at the rear of the receiver and the contacts on the pushbutton clip on the track (close-up photo above right). When the circuit is completed the motor operates and turns the disc, which is mechanically linked to the tuning capacitor, thereby also turning the capacitor vanes. The motor runs until there is a break in the track on the circular rear disk, at which point the station should be in tune. It is this track break point that extinguishes the setting lamp mentioned in the previous paragraph. As the tuning capacitor cannot turn though 360° the receiver has to determine whether the motor should spin left or right to enable the station to be tuned in. This is accomplished by virtue of the fact that two semicircular tracks exist on the rear disk, and depending on which of the two tracks the disk clip contact connects with power is applied to turn the motor in the appropriate direction. Automatic Frequency Correction (AFC) is also provided on this receiver, because over the course of time wear on the mechanical motor components (or even frequency drift from the transmitter) might cause the station not to be perfectly tuned in. Therefore the AFC will correct any minor discrepancies.

In use the motor tune system is certainly audible as the motor trundles the tuning capacitor and pointer around the fairly large dial. Observing the set from the rear in subdued lighting is also vaguely alarming, as sparks can be seen to be flying off the dual concentric rails as the various clips are passed. I have of course considered attempting to reduce this effect with switch cleaners or even an HB pencil judiciously applied, though on the other hand technology this basic cannot be expected to work faultlessly after all these years!

A sheet of perforated labels was supplied including all the popular radio stations of the day that the user was likely to select, and these could be slid in the bakelite window recess adjacent to the switch to give a professional finish to a set customised for the owner. Presumably the original owner of the radio pictured must have been happy with the original factory settings, as not a single one of the spare station labels from the card has been used. Also shown in the picture are the original instruction book and guarantee card. Ekco’s are generally desirable anyway, and this one is no exception. It provides good everyday performance with a luxury that, as a result of World War II, was rarely to return ever again in British sets.

Continue to look at some Post-War Ekco's