Eric Jacobsen wrote:

On Fri, 08 Aug 2003 13:31:25 -0400, Jerry Avins wrote:

... It has been one of my enduring regrets
that I didn't ask to keep the bulb. It was probably thrown out.

Jerry

I think that one may have been intended for an embassy somewhere...

About a year later, I read about such a bulb in QST. The author believed
that Edison-effect electrons excited a self broad-band resonance in the
doubly coiled filament, sustaining oscillation by a mechanism I forget,
but that seemed reasonable at the time. Incandescent lamps are filled
with low-pressure nitrogen to avoid damage from the Edison effect, and
interaction with the gas figured in his explanation. It was that
explanation that led me to build an open-air triode. I was surprised as
anyone when that worked, and I took it as a confirming instance for the
now-forgotten explanation.

Jerry
--
Engineering is the art of making what you want from things you can get.
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯ ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯ ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯

Eric Jacobsen wrote:

On Fri, 08 Aug 2003 13:31:25 -0400, Jerry Avins wrote:

... It has been one of my enduring regrets
that I didn't ask to keep the bulb. It was probably thrown out.

Jerry

I think that one may have been intended for an embassy somewhere...

About a year later, I read about such a bulb in QST. The author believed
that Edison-effect electrons excited a self broad-band resonance in the
doubly coiled filament, sustaining oscillation by a mechanism I forget,
but that seemed reasonable at the time. Incandescent lamps are filled
with low-pressure nitrogen to avoid damage from the Edison effect, and
interaction with the gas figured in his explanation. It was that
explanation that led me to build an open-air triode. I was surprised as
anyone when that worked, and I took it as a confirming instance for the
now-forgotten explanation.

Jerry
--
Engineering is the art of making what you want from things you can get.
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯ ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯ ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯

Frank Dinger wrote:

Without saying anything, I went over to the
stairway switch and turned it on and off a few times. "On" caused the
interference. When we swapped the bulb with one in a floor lamp, the
floor lamp caused the same interference. It has been one of my enduring
regrets that I didn't ask to keep the bulb. It was probably thrown out.
================
That bulb was probably an old coiled 'Edison' type . They were /are known to
form a tuned circuit resonating in the old TV band 1 ( about 48 - 62 MHz)
acting as a TX when power is applied.

Frank GM0CSZ / KN6WH

Thank you thankyouthankyou! I've been called a crazy liar more than once
over that bulb. There was no channel 1 when that incident happened, but
I suppose that a small change of geometry could raise the frequency. The
explanation in QST had it that the frequency was swept over a fairly
large range as the voltage varied during a cycle.

Jerry
--
Engineering is the art of making what you want from things you can get.
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯ ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯ ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯

Frank Dinger wrote:

Without saying anything, I went over to the
stairway switch and turned it on and off a few times. "On" caused the
interference. When we swapped the bulb with one in a floor lamp, the
floor lamp caused the same interference. It has been one of my enduring
regrets that I didn't ask to keep the bulb. It was probably thrown out.
================
That bulb was probably an old coiled 'Edison' type . They were /are known to
form a tuned circuit resonating in the old TV band 1 ( about 48 - 62 MHz)
acting as a TX when power is applied.

Frank GM0CSZ / KN6WH

Thank you thankyouthankyou! I've been called a crazy liar more than once
over that bulb. There was no channel 1 when that incident happened, but
I suppose that a small change of geometry could raise the frequency. The
explanation in QST had it that the frequency was swept over a fairly
large range as the voltage varied during a cycle.

Jerry
--
Engineering is the art of making what you want from things you can get.
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯ ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯ ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯

On Sat, 09 Aug 2003 17:35:45 -0400, Jerry Avins wrote:

Engineering is the art of making what you want from things you can get.

Love that byline.

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice:(480)460-2350 | |
| Fax:(480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

For proper E-mail replies SWAP "-" and "_"

Why is it that Democrats can't debate politely?
And are only rude and interruptive.
Lack of mental capacity?

On Sat, 09 Aug 2003 17:35:45 -0400, Jerry Avins wrote:

Engineering is the art of making what you want from things you can get.

Love that byline.

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice:(480)460-2350 | |
| Fax:(480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

For proper E-mail replies SWAP "-" and "_"

Why is it that Democrats can't debate politely?
And are only rude and interruptive.
Lack of mental capacity?

Jerry Avins wrote:

Eric Jacobsen wrote:

On Fri, 08 Aug 2003 13:31:25 -0400, Jerry Avins wrote:

... It has been one of my enduring regrets
that I didn't ask to keep the bulb. It was probably thrown out.

Jerry

I think that one may have been intended for an embassy somewhere...

About a year later, I read about such a bulb in QST. The author believed
that Edison-effect electrons excited a self broad-band resonance in the
doubly coiled filament, sustaining oscillation by a mechanism I forget,
but that seemed reasonable at the time. Incandescent lamps are filled
with low-pressure nitrogen to avoid damage from the Edison effect, and
interaction with the gas figured in his explanation. It was that
explanation that led me to build an open-air triode. I was surprised as
anyone when that worked, and I took it as a confirming instance for the
now-forgotten explanation.

Open-air triode?? Do tell, you have me fascinated...

Rob

Jerry Avins wrote:

Eric Jacobsen wrote:

On Fri, 08 Aug 2003 13:31:25 -0400, Jerry Avins wrote:

... It has been one of my enduring regrets
that I didn't ask to keep the bulb. It was probably thrown out.

Jerry

I think that one may have been intended for an embassy somewhere...

About a year later, I read about such a bulb in QST. The author believed
that Edison-effect electrons excited a self broad-band resonance in the
doubly coiled filament, sustaining oscillation by a mechanism I forget,
but that seemed reasonable at the time. Incandescent lamps are filled
with low-pressure nitrogen to avoid damage from the Edison effect, and
interaction with the gas figured in his explanation. It was that
explanation that led me to build an open-air triode. I was surprised as
anyone when that worked, and I took it as a confirming instance for the
now-forgotten explanation.

Open-air triode?? Do tell, you have me fascinated...

Rob

"Rob Judd" wrote in message
...

Open-air triode?? Do tell, you have me fascinated...

IIRC, field effect triodes {FETs} were made about the same time as the first
vacuum tubes, but they didn't work well enough, given materials technology
of the day.

"Rob Judd" wrote in message
...

Open-air triode?? Do tell, you have me fascinated...

IIRC, field effect triodes {FETs} were made about the same time as the first
vacuum tubes, but they didn't work well enough, given materials technology
of the day.