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Success Stories If you have successfully repaired or restored a piece of equipment, why not write up what you did and post details here. Particularly if it was interesting, unusual or challenging. PLEASE DO NOT POST REQUESTS FOR HELP HERE! |
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28th Mar 2017, 7:28 pm | #1 |
Dekatron
Join Date: Feb 2009
Location: Chesterfield, Derbyshire, UK.
Posts: 3,761
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Columbia DC radio
And now for something different. This it a DC only radio the valve line up is
DCPen DC hl DCsg DC2sg All very rare valves , The story is when I bought the radio they were two valves missing ,the only DC equiv were different voltages and different current ,and these took some finding. The voltage for the heaters came to 40 volts but the two replacement were only 0.1a whereas the two original were 0.3a so a shunt resistor was fitted accross the two 0.1a ones. I proceeded to construct a power supply to supply 40v DC and HT about 180 volts.a 120 volt tx was used for the ht and a low voltage one for the heaters , Bridge rectifiers were used in both HT and LT .That's the power supply on it's own shelf top r/h corner of the cabinet. All the usual capacitors in the can's were replaced , the chassis was very clean for it's age ,but the cabinet req a total strip and re lacquering . The set works very well as with all TRF set you have to know how to drive them . Mick. |
28th Mar 2017, 11:50 pm | #2 |
Dekatron
Join Date: Apr 2005
Location: Bewdley, Worcestershire, UK.
Posts: 4,748
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Re: Columbia DC radio
What a fascinating radio. Well done on restoring it, there can't be many DC mains radios still in existence, let alone working. Brilliant job!
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Phil Optimist [n]: One who is not in possession of the full facts |
29th Mar 2017, 7:39 am | #3 |
Dekatron
Join Date: Jan 2005
Location: Oxford, UK.
Posts: 17,846
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Re: Columbia DC radio
Lovely cabinet, in an elegant and understated way,
Well done, Mick! |