[QRZ] 127 volts coming from the wall ruin older radios?

[QRZ.com via rec.radio.amateur.moderated Admin]

"Boat Anchor" & Classic Equipment

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127 volts coming from the wall ruin older radios?

Posted: 09 Apr 2019 08:40 AM PDT
https://forums.qrz.com/index.php?threads/127-volts-coming-from-the-wall-ruin-older-radios.653615/



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TS-830S Intermittant/Erratic ALC on CW Tune-up

Posted: 09 Apr 2019 06:38 AM PDT
https://forums.qrz.com/index.php?threads/ts-830s-intermittant-erratic-alc-on-cw-tune-up.653596/



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Heathkit TC-2 tube tester meter adjustment.

Posted: 08 Apr 2019 08:03 PM PDT
https://forums.qrz.com/index.php?threads/heathkit-tc-2-tube-tester-meter-adjustment.653601/

[Fred McKenzie]

Post by QRZ.com via rec.radio.amateur.moderated Admin
"Boat Anchor" & Classic Equipment
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127 volts coming from the wall ruin older radios?

Suppose a radio was designed to work with a "nominal" 110 VAC. It
should be able to stand a 10% variation, or 99 to 121 VAC. If it was
connected to 127 Volts, that would be 127/111, or 14.4% high.

Solid state rectifiers and electrolytic filter capacitors would be
places to look for trouble. In addition to marginal voltage design, a
filter capacitor might just go bad from old age!

Fred

[Ralph Mowery]

Post by Fred McKenzie
Suppose a radio was designed to work with a "nominal" 110 VAC. It
should be able to stand a 10% variation, or 99 to 121 VAC. If it was
connected to 127 Volts, that would be 127/111, or 14.4% high.
Solid state rectifiers and electrolytic filter capacitors would be
places to look for trouble. In addition to marginal voltage design, a
filter capacitor might just go bad from old age!
Fred

I would say the tube filiments would go first. For my boat anchor
station (Viking II and Hamurlund receiver) I have a variact and set the
voltage to 115 or less.

Most of the time my AC voltage is from 122 to 124 volts comming out of
the wall. Verified with a Fluke meter that was verified to be with in
1/2 of a percent near that voltage.

[Scott Dorsey]

Post by Fred McKenzie
Suppose a radio was designed to work with a "nominal" 110 VAC. It
should be able to stand a 10% variation, or 99 to 121 VAC. If it was
connected to 127 Volts, that would be 127/111, or 14.4% high.

Yes. That's not outrageously high, but it's a little high, and if the
owner has replaced selenium rectifiers and tube rectifiers with modern
silicon replacements, internal voltages will climb still higher.

It's not hard to take a small 12V filament transformer and create a bucking
transformer to reduce the line voltage from 127V down to 115V. Does not
take a big transformer... a transformer with a 2A secondary will give you
2A of 115V.
--scott