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Old 28th February 2009, 12:27 PM   #1
dognut is offline dognut  United States
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Default help 124.3 vac

Hello to all. My house voltage here in south florida is 124.3 volts ac. Is there any cheep way to reduce this for my tube reciever? Thanks, tom
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Old 28th February 2009, 12:43 PM   #2
Geek is offline Geek
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Hi Tom,

I wouldn't worry about it.

The voltage where I live for as long as I can remember measuring it has been 126V, dropping to 122V at dinnertime. All my tubes still live

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Old 28th February 2009, 01:05 PM   #3
jeapel is offline jeapel  Canada
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Location: quebec
just a step down transfo

if you get a step up just reverse the
secondary wires
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File Type: gif set down transfo.gif (1.8 KB, 125 views)
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Old 28th February 2009, 07:12 PM   #4
kevinkr is offline kevinkr  United States
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help 124.3 vac
You can use an adequately rated " filament" transformer to buck the line voltage - not a bad idea as most tube receivers were designed at a time when nominal line voltages ranged between 110V -117V, and everything runs a little hotter than it should on current line voltages. (Some gear like my Realistic amplifier are so hard on output tubes that the additional line voltage results in the amplifier killing modern output tubes despite running close to the original amplifier design values.)

Basically the way it works is if you need 2 - 3A of AC choose a transformer with at least 30% more capacity than required, (say 4 - 5A) this will keep things quiet and cool. Wire the primary in parallel with the incoming AC, wire the secondary in series with the incoming AC (AFTER the primary connection) and verify that the line voltage is lower (bucking) - if not reverse either the primary or secondary connections depending on which is easiest.

Use a slow blow fuse ahead of the whole thing rated at no more than the rating of your filament transformer.. (4 - 5A with a conservatively rated 5A transformer)

Small toroids come in a variety of secondary voltage ratings, but even a conventional 6.3V filament transformer will drop things to around 118V which is fine. (If your receiver was rated for < 115V operation a 9 - 12V secondary will do the job nicely.)

This approach is generally very inexpensive and can result in a very quiet, compact unit.
"To argue with a person who has renounced the use of reason is like administering medicine to the dead." - Thomas Paine
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Old 28th February 2009, 08:37 PM   #5
eds65gto is offline eds65gto  United States
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Location: Mt Pleasant Sc
After complaining a few times over the last two or three years I finally got someone who knew how the lower the voltage at my house a couple of volts. Now the voltage is around 120 to 122 v instead of 123 to 125v at times. The tech told me that there were a number of people that complained when he came to my house , so maybe it takes a few people to make noise.
The tech said the voltage can be adjusted at the sub station to lower the voltage. Much Better !
Hope this helps
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Old 1st March 2009, 03:12 AM   #6
Poindexter is offline Poindexter  United States
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Location: Maui, Hawai'i, USA
There are line conditioners that can do this. &nbsp;They are fancy kit, and not cheap, but they reconstruct a virtually perfect sine wave that's adjustable over a certain limited range. &nbsp;This would not only solve your voltage problem, but take the ubiquitous fluorescent lamp and switching power supply rubbish off there as well, giving you the killerest starting base for your rig possible.

Google is your friend.


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