Ekco CR280 valve/tube car radio, 1950s

N_Cook · 2008-06-23T09:17:20+00:00

Story so far , had to replace a number of corroded/failed socket contacts and now have all 4 heaters working . Valves all tested ok on Avo CT160. Vibrator is working giving HT1 of 130V or so on low volume and 160V or so on high volume, yes that way round, should be about 270V. Severe noise crackle on speaker that varies across the tuning but no hint of radio reception. Next stage is to separate ps and radio sections by making an umbilical so I can monitor the valve base tags, but where to go next ? Something loading the vibrator or a failing vibrator ?, what sort of load to put across it to simulate a proper working radio ? Overall consumption should be about 2.7 amps at 12V , so extract 4 heaters and bulb from that but how to split the HT1 and HT2 loads and how much loss in the ps ? I can now see that the puttylike stuff around the vibrator is to damp sympathetic resonance of the otherwise bell mechanism inside. -- my OCR'd Cross-reference of pre-1960 radio valve types to models

Jun 23, 2008 22 Replies

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N_Cook 18 years ago

short.

use.

switches,

Kudos, great job! 'Specially on having the points running with little visible fireworks. The hash should quiet down with shields in place.

Bill(oc)

Easier than that, just moved the aerial to the other side of the bench as well as putting the internal screen back and the can back around the hummer. Secreted some heated silica gel under the foam and sealed around the base, before fitting back in with hot-melt glue all around the can, for sound absorbtion.

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on

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Meat Plow 18 years ago

Will the glue melt or soften? I've worked on a couple vibrator radios way back when and I recall them running a little too hot for hot glue;.

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N_Cook 18 years ago

the

250V

fair comment. This one after running for 20 minutes, in can , but not in surrounding casing or in a dashboard was barely detectably warm. The original putty or mastic softened and quite easily fell away, with the hot-air gun at about the same temperature as hotmelt

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on

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