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Vintage Radio (domestic) Domestic vintage radio (wireless) receivers only. |
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29th Dec 2006, 6:05 pm | #1 |
Pentode
Join Date: Mar 2005
Location: Cairneyhill, Fife, UK.
Posts: 135
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Philetta 273; running at 230v on 220v tap.
I have recently obtained one of these sets from Germany, model BD273U.
Like most AC/DC sets of this era there is a selector to allow the user to choose the correct domestic voltage. Rather than the wire with the nut common on British sets which was moved to the correct point on the dropper it takes the form of a plug. The voltage rating only goes up to 220v. Will it do any harm to run the set on our domestic voltage ? given the 20 volts or so difference and would it be wise to modify the resitance in order make the set compatable ? Alex Last edited by Darren-UK; 6th Aug 2007 at 9:58 pm. Reason: Model variant added and general tidying. |
29th Dec 2006, 6:13 pm | #2 |
Retired Dormant Member
Join Date: Dec 2003
Location: North London, UK.
Posts: 6,168
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Re: Philetta 273
It's better for the valves to run their heaters at the correct current. You could add resistance. Alternatively use a capacitor dropper instead of the entire dropper which will keep the heat well down.
The HT is not usually so critical. |
29th Dec 2006, 7:33 pm | #3 |
Moderator
Join Date: Jun 2003
Location: Oxford, UK
Posts: 27,787
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Re: Philetta 273
The simplest solution is to add another 200 ohms to the heater chain, which will drop 20 volts. As Jeffrey says, replacing the dropper with a capacitive or diode dropper will also work but this requires a bit more effort: http://www.vintage-radio.com/repair-...per-calcs.html
You can also include a smaller but higher wattage resistor in the mains lead to drop a bit of voltage. You can run the set directly from a 240V supply, but this is likely to shorten valve life, not something you want to do with a UL41 output valve (if that's what it uses). Good luck, Paul |
31st Dec 2006, 1:20 am | #4 |
Heptode
Join Date: Jan 2004
Location: Stockport, Greater Manchester, UK.
Posts: 826
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Re: Philetta 273
Even easier is to just remove the wire from the voltage selector to tag on the dropper which is the junction of the 50R and 150R sections.
Martin. |
1st Jan 2007, 9:48 pm | #5 |
Pentode
Join Date: Aug 2005
Location: North Warwickshire, UK.
Posts: 108
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Re: Philetta 273
Hi Retroaudio, as Paul suggests you could add an extra resistor in the mains lead. I bought from the pound shop a small extension lamp which consisted of a 13 amp plug a small length of 3 core cable and a lamp holder. To this I added a 13 amp socket and an oblong plastic box, big enough to fit the 13amp socket and lamp holder. I wired up the 13amp plug and socket in series with the "live"wire in the lamp holder. I found by inserting a 60 watt lamp into the lamp holder I could get 220v to feed any "like" radio with no effort. This way you dont alter the wiring of any set and you always have a "test rig" to hand when required. Just check the voltage when on load with the lamp in place as I've found some bulbs are prone to be out of tolerance and you may need a 40watt or 100watt instead of the 60watt lamp. Regards Brian. oops!. PS change the 13 amp input fuse for a more friendly 3 amp one.
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