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General Vintage Technology Discussions For general discussions about vintage radio and other vintage electronics etc. |
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29th Jul 2019, 8:35 pm | #21 |
Dekatron
Join Date: Jul 2007
Location: Penrith, Cumbria, UK.
Posts: 3,684
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Re: (Another) MW/LW interference problem
Well... They won't now!
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Regds, Russell W. B. G4YLI. |
13th Aug 2019, 8:23 pm | #22 |
Pentode
Join Date: Nov 2007
Location: Cork, Ireland
Posts: 134
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Re: (Another) MW/LW interference problem
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13th Aug 2019, 9:00 pm | #23 |
Dekatron
Join Date: Oct 2003
Location: Croydon, Surrey, UK.
Posts: 7,548
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Re: (Another) MW/LW interference problem
Probably causes as much interference as a spark transmitter.....
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There are lots of brilliant keyboard players and then there is Rick Wakeman..... |
19th Oct 2019, 11:14 pm | #24 |
Dekatron
Join Date: Aug 2016
Location: Colchester, Essex, UK.
Posts: 4,081
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Re: (Another) MW/LW interference problem
..Update.. Just had to move the (Bison Bede, not Stannah) stairlift to admit a new sofa into the house, plugged the SMPS back in for a few hours but the (twin) 12v Nicad packs show no voltage whatsoever.
Tested the output of the 33v power supply with a 24w 24v lorry lamp; this resulted in a very small spark at the base of the bulb, and the faintest cheam of light from the lamp, which rapidly fades. Unfortunately it appears to me that the power supply is 'gubbed' (as bigclive would say) and has probably killed the NiCads by neglect. There is inevitably a big fat capacitor in the power supply (visually ok but possibly dried out) which i will discharge, remove and test. What IS gratifying is the amount of SMPS trouble-shooting info on the 'web. Just to add complication there is a control board between the 33V DC line and the battery leads. Text on one of the components infers that software is present. (Oh good..) No indication whatsoever that the 'lift was not parked properly on it's charging point. I will update as it seems this sort of failure (and resultant RF interference) is a common problem. Dave |
20th Oct 2019, 11:17 am | #25 |
Dekatron
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 13,951
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Re: (Another) MW/LW interference problem
Check the voltage on your NiCd packs before trying to charge them. Many modern chargers deliberately won't produce a significant output-current/voltage unless they detect a battery with a certain-degree of charge (a certain minimum voltage); this is a safety precaution to protect against failing battery-packs.
[I've got an old NiCd-powered portable drill here whose battery-packs are all-but-dead: the charger refuses to recognise them unless I hook an 18V supply to the battery for a few minutes before putting it on the charger - this puts just enough charge into the battery for it to be recognised by the charger - which then goes through a proper charge-cycle to the point where I can actually use the drill for a bit.] |
20th Oct 2019, 11:22 am | #26 |
Dekatron
Join Date: Aug 2016
Location: Colchester, Essex, UK.
Posts: 4,081
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Re: (Another) MW/LW interference problem
Thanks, yes, they will certainly need to be gently zapped by a 'dumb' charger in the first instance as they are showing zero volts. In truth they are probably ruined, but we'll see.
Dave |