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[email protected] heathjohn2@gmail.com is offline
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Default NE-51 Neon Bulbs

On Tuesday, November 24, 2015 at 4:32:36 PM UTC-5, wrote:
On Friday, November 20, 2015 at 3:55:22 PM UTC-5, Madness wrote:
Just acquired a bunch of these lamps. They're in the same mini-bayonet
style as lamps like the #44/47. But would anyone know if these lamps can
be connected directly to 120 volts? Or do they need a resistor, @ if so,
what value?


Mpfffff....

This lamp was used by Zenith and more than a few other manufacturers in the 1950s/1960s as an indicator lamp (on/off) at about the time that radio manufacturers started to become concerned about user-servicing and hot-chassis radios - something that never really bothered them in the past. The worked on the theory that a neon lamp was far less likely to burn out than the old standby #44 or #47, so that loose fingers were less likely to get nipped. ASIDE: Audio devices held on to incandescent lamps (With specific reference to the 47) well into the 80s, before shifting - very slowly - to LEDs or Fluorescent lamps. But, they had transformers on board to isolate the chassis.

It is designed to operate at ~120V AC. It _CAN_ operate at ~120V DC, but only one post will light. It will trip (glow) at about 90V +/-.

Unless there is a voltage dropper in the circuit, it will fail quickly at 220 or 240 V - that is voltages outside of Japan and the Americas. As supplied, it has a 100K resistor in series with the lamp. For conversion to 220V, I have heard values of up to an *additional* 220K in series. Try there and work back if you wish to operate at 220V.

As about 2/3 of my hobby time is dedicated to vintage radios, I am quite familiar with, and keep a bunch of these lamps in my spares-box.

Peter Wieck
Melrose Park, PA


Yes antique radios. I like them to with filaments glowing in the tubes.For younger members the tube is old glass bulb valve with the led on top. Some of them have the magic green eye for RF strength if you are lucky enough to find one. Neat trick that you can do with the old variable capacity plate tuner. Charge it to 30 volts with a neon bulb across. When you turn the tuning knob to open the plates the neon bulb will flash? With only 30 volts how could it flash a neon bulb with a 80 volt trigger voltage?