Apparently a lot of people have been looking for this gem of an eBook and the associated images that were lost in the move to WordPress. The content has now been imported and a new gallery created so this excellent work lives on.
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!
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.
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.
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 underside view showing absence of BFO cover, discarded at some time due to overcrowding. This chassis has even gaps everywhere: a good layout.
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.
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.
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 general view, showing the cabinet and the unusually tidy chassis topside layout. Notice the huge gold-metallized 6TH8G triode-hexode mixer.
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.
I am trying to get access to a new band, for Australian Amateurs. Originally a UK band, much of Europe, plus parts of Africa and the Middle East now have it. It will allow experimentation, including with Trans-Equatorial Propagation, as well as being handy during emergencies.
