These pictures show views of the Philips 2514 showing the compactness of the design

Top view showing the coil pack with its wavechange switch mounted on the centre metal screening plate dividing the grid and anode coils. The left side contains the grid coil with its tuning condenser. Just visible on the end panel is a tubular device carrying three integral fixed condensers for allowing different degees of selectivity/sensitivity to be selected via three aerial sockets. On the left of centre, coloured black is a large high Q aerial or grid tuning coil of the RF amplifier. On the right are the anode and grid coils of the second stage with the tuning condenser. Coupling between the valves is via the pair of vertically mounted coils, the rear of which carries a variometer assembly (a pick-up coil which may be moved mechanically to alter the degree of coupling between two others) for setting the degree of feedback or regeneration. This is one of several ways, in those days, of implementing a reaction control. This inductive technique gives a noise-free infinitely variable setting. The mechanical control is via a rod passing through a hole drilled through the centre of the tuning condenser spindle. Setting of both the large tuning condensers is via slow motion drives which are integral to the design of the condensers and offset a few inches from the spindle carrying the condenser vanes. The tuning scales are fixed to rear projections of the condenser spindles and are calibrated with the usual 0-180. The end plates are made of black bakelite but that on the right is plated on the inside with metal to minimise hand capacity which would affect stability. The small pegs around the end plates are used for accommodating the case screws.

Rotating the chassis through 90 degrees reveals the valve bases, two of which, those for the detector and output valves are integated within a black bakelite assembly. The rectifier base on the left, is integral to its own detachable assembly.

This view shows the screened grid RF amplifier on the left, next to the power rectifier. On the right are the detector valve and the output valve. The output transformer is on the extreme right next to the power output valve. It was important to keep the two sets of tuning coils well away from each other to prevent instability through unwanted positive feedback.

This view shows the mains transformer on the bottom right next to a decoupling condenser block. The device at the centre of the lower edge is a safety switch socket which is used to disconnect the mains transformer primary feed. The lower part of the case covers the valves and most of the exposed connections carrying high voltages and incorporates an isolated metal tongue which inserts into the safety socket. When the panel is removed the HT supply is disconnected from the set's wiring. The centre metal plate to the left of the rectifier screens the RF amplifier valve from the detector valve.

See more>>