Marconi CR100 mounted in a home constructed handling frame which protects the chassis in any position while it is receiving attention on the bench.

PSEI Trophy-8 has paxolin valve sockets which cause earthing problems for the solder tags, as shown here on the RHS mounting screw sandwiched between the
paxolin and the chassis - look carefully!

GEC BRT400K showing a re-soldered chassis seam. Sprung joints are very common indeed on this model.

Eddystone EA12 uses nylon dialdrive pulleys which swell over time due to water absorption. The result is excessive pointer travel from end to end.

Marconi CR100 centrally captivated band change cord, which proved extremely difficult to replace. Look carefully to see how the cord enters the little metal drum in two places. It’s very difficult indeed to assemble it correctly.

GEC BRT400K steel dialdrive wire runs in greased brass guides. Early variants (without front panel handles or dial lock) used pulleys. Dial lamps have been removed for clarity.

British Army R209 Mk2 pressure testing set-up, showing the desiccator which has to be temporarily replaced by a purging bung for this operation. When all is well, the manometer shows unchanging pressure after initial pumping.

National NC100XA dialdrive endstop plate shown standing vertically with one bevelled corner visible. This is a very poor design which required careful filing to operate correctly.

KW202 tuning capacitor, showing its non-standard glued plastic cover which considerably reduces VFO drift. Also shown is the Kokusai 455kHz SSB mechanical filter.

Murphy B40D tuning gang, with its fragile ceramic shaft which snaps if the radio has been dropped. This is a scrap set, hence the dead leaf on the LO valve socket!

Racal RA17L filmstrip scale, a thoroughly well engineered solution. Dial bulb removed for clarity. The big disc is the MHz display dial. Its outer knurling bites the dial lock brakeshoe rubber when required.

GEC BRT400K SRBP tag board, now patched with an FR4 plate as is commonly necessary on this model.

Murphy B40D needs air to enter this very heavy radio from underneath. The tuning chain can be seen wound round its small drive sprocket which can be seen through the big hole in the casting.

Marconi Atalanta panel damage caused by botched knob removal, a common problem due to poor knob design.

Kwikfyl crayons, a tin of Humbrol enamel and the pointed application tool used by the writer.

Philips EFM1, a rare magic eye with integral AGC-controlled AF pentode on the problematic CT8 base. Also shown is an RCA 7360 beam-deflection valve.

Eddystone S770R/1 special RF valve socket with two turned pins instead of the standard stamped items.

British Army R209 Mk2 desiccator cartridge, with its rubber O-ring seal. Shown with home made pressure testing adaptor which includes the Schrader valve used to prove sealing.

Collins R-390A bellows coupler employed to turn the BFO shaft whilst accommodating squeeze & stretch. At the bottom of this picture are two Sprague Black Tubular (BT) capacitors which must be replaced. To the left of them is a Vitamin-Q which a reliable type.

Hand tools most commonly used by the writer in his own workshop for radio restoration work. Yes, the roll of kitchen towel is there deliberately! The chassis to the left is a Marconi CR100/B28.

Marconi CR100 is a very properly engineered radio which has an ill-deserved reputation for drift and unreliability. The little subchassis standing up to the left of the gang is the noise limiter, with its toggleswitch.

Marconi CR100 showing ceramic pillars used to replace original stud-ended tubular capacitors. A modern polyester capacitor is strapped across the pillar from top to bottom, to replicate the original earthing arrangement.

Marconi CR100 band change shaft is split to allow the flexibility necessary on mid production chassis such as this one. The misalignment is due to a design or manufacturing error which was fixed in late production models.

Marconi CR100 replacement mode switch is a very tight fit. Note use of wire identifier tags and ink legends on the switch wafer.

Marconi CR100 underside view showing absence of BFO cover, discarded at some time due to overcrowding. This chassis has even gaps everywhere: a good layout.

Eddystone EA12 showing two of these receivers, both unrestored but in basically good condition.

National NC100XA interior view of the catacomb casting. Centre top biscuit removed, to show stator contacts visible through the shaped hole. Rack & pinion drive mechanism to the right of the carriage.
Notice the mighty guide bar to the left of the carriage!

Eddystone S358X has a very unreliable single pole mains switch which can fail to break. B40s use the same family of switch: a potential fire & safety hazard.

GEC BRT400 Mk1 IFT carries 240VDC between the RHS (secondary) bobbin and its overwinding, shown here. There is no gap and no meaningful insulation so flashovers are common, especially in damp conditions. Notice the Philips beehive trimmer, a type prone to short circuits. Later BRT400D IFTs had mica fixed capacitors but kept the beehives.

Eddystone EA12 has an unreliable mains connector, relying on a single-sided blade to connect the earth.

GEC BRT400D with typical decomposing bitumen-impregnated Iron HT components, a very common cosmetic problem on GEC and Philips sets - and also on the RCA AR-8516L.

Marconi CR100 grid caps rewired in 16/0.2mm PVC for the LO (left), and RG316/U PTFE coax cable for the mixer (right). Also shows Hellermann insulating sleeves.

EKCO R1155A original screened cable fitted with a new 16/0.2mm PVC inner, to preserve appearances. The new PVC insulation can be seen next to the grid cap.

Philips 6H8MG, a rare double-diode pentode used in the unusual AME 7G1680BA receiver. The nearest sensible equivalent is the 6B8 from the USA

This PSEI Trophy-8 uses Meccano chain drive. One example has been seen with a rubber belt instead. Probably the writer’s set was modified at some time.

PSEI Trophy-8 chassis design gives plenty of room to its RF box. Note the retrofit HT fuse mounted by the output transformer, and the new mains cable, fitted by the writer. These modifications are intended to promote safety.

PSEI Trophy-8 front panel shows the barometer glass. Note the circular legend rings missing from two controls.

PSEI Trophy-8 general view, showing the cabinet and the unusually tidy chassis topside layout. Notice the huge gold-metallized 6TH8G triode-hexode mixer.

GE compactron type 6AS11 contains two signal triodes and an output beam tetrode, shown alongside a 5749/6BA6W pentode.

Acorn glass triode which seats into this type of special ceramic socket for the Hallicrafters S36 receiver. Also shown is a later, more advanced 6CW4 nuvistor triode which was in volume production for USA TVs for a couple of years.
These were very high technology devices employing ceramic/metal seals.