VRW  PUBLICATIONS          HOME   |   BOOKS  |   SERVICE DATA   |   RESTORATION   |   RADIO HISTORY

 

CHASSIS RESTORATION: PHILCO 444

WOOD  BAKELITE  CHASSIS  ETHICS  DIODE, TRIODE  TETRODE, PENTODE  STANDARDS PHOTOGUIDE  VIDEOS

PILOT  BUSH  EKCO  COSSOR  PHILCO  BAKELITE HISTORY VALVES DIODE, TRIODE  TETRODE, PENTODE  STANDARDS

PHILCO 'PEOPLE'S SET' model 444

One of a series of so-called "People's Sets", a term generally assumed to have been used because of the supposed similarity between the Bakelite cabinet versions of the set and the rear window of the Volkswagen (People's car). The release date of the 444: 1936. The chassis is a three valve ‘short’ superhet with only one tuned IF stage and an output valve doubling as detector and AVC. The mixer is of the self-oscillating type and IF trimming is by compression capacitors. AC mains, full-wave valve rectification. ME loudspeaker. Two waveband, no tone control. Bakelite cabinet.

Brief restoration summary

The cabinet was sound with no cracks or severe scratches but it was very dull and dirty. The grille cloth damaged, badly soiled and rotting. There was no rear cover. Surprisingly there was little rust on chassis metalwork, but it was very dirty and encrusted with a greasy layer. At some time, additional loudspeaker leads had been fitted, not very expertly. The pointer on the scale was in the wrong place on the spindle, rendering it invisible in use. The two halves of the tuning gang capacitor had been wired together; a common misconception, where people mistake a 'wire wrap' low-value capacitor for a broken soldered joint, even though common sense should suggest that a twin-gang capacitor should remain so. The knobs are on the wrong spindles. All the foregoing indicated that the set had been 'got at' by an inexpert someone, previously. Illumination of dial seemed weak. The tuning gang and dial assembly was loose. Main smoothing capacitor, which should be visible above chassis, was missing. One of the special chassis securing bolts was also missing.

Valves tested:

 PENDD61 output valve: Almost 100% output on pentode section. Both diode sections OK.

80 rectifier: Although output was satisfactory on both anodes, some worrying ‘flicking’ of the tester meter needle indicates a problem.

78E I.F.amplifier: Low emission.

6A7 mixer/oscillator: Low emission.  

Accordingly, new valves fitted were Mixer/oscillator, I.F. amplifier and rectifier. Output valve was useable.

Under-chassis examination and work.  

Volume control dismantled, cleaned and reassembled. Wavechange switch cleaned. Valveholders cleaned.

The incorrect double reservoir and smoothing cap that someone had fitted by hanging dangerously in the wiring beneath the chassis was removed and a correct metal tubular replacement capacitor fitted to original clip. New mains lead fitted, using a new grommet and a restraining clip. New mains plug fitted.

Replaced components include C8 (HT RF bypass), C11 (LF coupling), C5 (V1, V2 screen bypass), C12 (V3 pentode cathode-grid decoupling), R6 and R8 ( AVC coupling resistors). Replacement rubber washers bonded to screw plates in chassis corners. General clean-up.

Realignment.

Full realignment of RF and IF stages was carried out. An Advance signal generator was the signal source via a dummy aerial and output was measured using an Avo model 8 as an output meter.

Above chassis work.

Chassis metalwork degreased and cleaned. Valve screening cans cleaned. Valvecap connecting leads replaced/repaired. Incorrectly linked tuning gang wiring returned to originality. Tuning gang and scale dismantled and cleaned. New rubber bushes for tuning gang on reassembly. New dial lamp and wiring. Damaged loudspeaker cone repaired. New fabric fitted to baffle board. Knobs and cabinet degreased and polished.

Replacement back made from painted greyboard and fitted using 6BA bolts after repairs to the threads of the mounting holes.

PILOT  BUSH  EKCO  COSSOR  PHILCO

 

 

Philco 444

Internal view of completed Philco

 

Chassis before restoration

 
VINTAGE RADIO world: SIXTEEN YEARS OF WEB PRESENCE