Even More Old Radio Parts (11)


 I received a large box of radio parts in 2017. Presumably once belonging to a radio enthusiast, they date from the late 1920s to around 1939.


First.. a selection of fixed condensers, I guess dating from around 1930. I measured the GecoPhone condenser and got puzzling results. An ESR meter said it was 2.09uF at 0.27 ohms and an LCR meter reported 8.164uF at DC. An hour later, when the room was a little warmer I checked again and saw 2.93uF at 0.24 ohms and 10.34uF respectively. I imagine that the ESR meter uses an AC test voltage of some few KHz.






 Now some chokes or inductors.






 Views of a Varley HF Choke. Construction uses several series connected windings. This reduces resonance at a particular frequency and enhances the operation of the choke.



 There are several of these chokes in this junk box. Maybe a special offer was the reason?



Below, left a Bulgin choke marked 8-80 meters and bottom right another example but without a makers' name so probably a dreaded foreign import?










 Clearly the owner of the parts dismantled several old receivers to accumulate these assemblies.

They range from the late 1920s to about 1939.










 A low frequency choke made by Pye plus a couple of transformers







 Above left, several Dubilier resistors salvaged from an early radio and right a new Colvern wirewound resistor. Left, a slightly earlier wirewound resistor, probably foreign made.



Below a couple of valveholders both for horizointal mounting on a baseboard. The one on the left looks like a cheap no-frills foreign import.





 Left, an early Yaxley-style rotary switch and below a strange-looking component which is a reaction control. It was usual in cheap TRF radio sets to dispense with a volume control and rely on the feedback condenser to provide comfortable listening volume. This example marked for medium waves has a lower maximum capacity than one used for long wave reception. It can be dated to the era before medium waves were extended to 200-300 meters.




 Most of the parts in this junk box were tuning condensers, a mixture of types including compact solid dielectric and air-spaced.

Several have odd-shaped vanes which were designed to produce linear tuning dials.

Some examples have built-in slow motion drives and some feature both direct and slow motion drive.










  Above a couple of views of a 100pF split stator tuning condenser marked "Utility".




Left, this one was made by Ferranti and the pictures below this show a solid-dielectric reaction condenser made by Lotus Radio of Liverpool.




 Finally, another Lotus condenser, left plus a couple of foreign examples shown below...



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