The Edison Effect

by Bob Wexelbaum, W2ILP

Most people think of Thomas Edison as a great inventor or wizard. The truth is that the Edison Company employed technicians who were tasked with perfecting Edison’s dreams. When I was a kid I learned about Edison from two movies: “Young Tom Edison” staring Mickey Rooney and “Edison the Man” staring Spencer Tracy. There were few details about the 24 technicians who worked for Edison at the time that a practical incandesant lamp bulb was perfected. Nothing about Lewis Latimer, who was Edison’s only Black draftsman-technician. Latimer, the son of an escaped slave, had had experience working for H.P. Maxim’s father. Working independently, Latimer had invented a water closet for railroad trains. Edison’s staff was tasked with producing a light bulb that would last longer than as few hours before it would burn out. It was Latimer who first suggested the use of a carbon impregnated fiber filament, which became the standard for early long life light bulbs, although superior tungsten filaments were later developed. Early light bulbs were troubled by having carbon deposited on the inside of the glass envelope. There was also the problem of evacuating as many oxygen molecules as possible from the lamp bulb. If many air molecules remained this would lead to early burnout of the filament. A solution for removing air molecules led to the development of what is known as a “getter”. A getter is a strip of magnesium that is caused to burn suddenly by running an electric current through it. This would use up most of the oxygen that remained in the bulb or tube, however the getter flash might also cause undesired blackening or silvering of the glass envelope, which was later OK for vacuum radio tubes but not for light bulbs. While experimenting with getters it was found that a small electric current could be measured between the getter (or any metal device or plate) within the lamp bulb and the filament, even when there seemed to be no conductive path connecting the filament to the metallic plate. This mysterious curiosity became known as “The Edison Effect”. When a bulb was so configured it became what is now known as a vacuum tube diode. Even with no positive voltage connected to the plate such a diode could be used in a primitive radio receiver (crystal set) to replace a crystal diode, since it permits only electrons to travel from the filament to the plate. Emission of electrons from a hot filament became the basis for the new field of “electronics”, which (before the transistor was invented) was based solely on thermionic emission. Radio detection involves the rectification of bipolar modulated RF and any diode can serve as such a detector. However the sensitivity of a vacuum tube diode is poor when compared to a crystal diode. Only strong local radio stations can be received by the Edison effect. A sensitive spot on a galena crystal might enable a receiver to detect RF signals as small as 200 uVolts, while the Edison diode would only be good for receiving local signals that exceeded 600 uVolts. It was only after the triode was invented and RF and audio amplification became practical that diode vacuum tubes could be used for practical radio reception. The concept of diode tube rectification led to the development of power rectifiers. It is ironic that although the principle of vacuum tube rectification was discovered in his Menlo Park, NJ lab, alternating current (AC) power held little interest for Edison. He strongly believed that all electrical power distribution would only utilize direct current (DC).

PRESIDENT’S NOTE by ED GELLENDER, WB2EAV

I found out recently that Riley Hollingsworth, who had been virtually the entire FCC enforcement division for some years now, and who had an excellent rapport with the amateur community, has retired. Riley was a great help when we were having trouble with the Bethpage repeater frequency. Anyway, I can’t help but wonder about the timing of his retirement – coming so soon after the ARRL won a court decision over the FCC on BPL (broadband over Power Lines). I have no way of knowing anything about it; I just find it an interesting coincidence.

I have been working on the Bethpage repeater to get it working as well as possible. What I need is more user feedback. If you have any comments, make sure I get them. Things on the repeater seem to have gotten very quiet lately. Perhaps it has something to do with the summer and now that schools are back open, maybe everybody will be getting back into the old groove.

Northrop Grumman has announced to the member clubs (that includes us) that budgets have been approved and with proper documentation, some expenses will be reimbursed. In the past, and with proper documentation when Pat, KE2LJ was President, occasionally they would ask for receipts for reimbursement, but nothing happened. I will give it a try and hope that we get better results than Pat was getting.

The big news is the September meeting and picnic with Frank Fallon N2FF. Frank is always a pleasure to meet and listen to. Not only are we having a picnic with the usual hot dogs and hamburgers, etc. but we get to hear what is going on in the big picture. We will be by a large pavilion so we can hold it even in less than perfect weather. It is at the same place as we had for the June 2007 meeting: Marjorie Post Park in Massapequa. In general, to drive to there you take NY 135 (Seaford Oyster Bay Expwy) to its last southernmost exit -Merrick Road East. After about 3 miles you will see the park on your left. Go past the park, then at the end turn left onto Unqua Road. Make a quick left into the park and then head right to go west through the second parking lot toward the far left corner. Park and then walk about 200 feet further west to the picnic pavilion.

Looking forward to seeing you there.

Ed, WB2EAV

GRUMMAN AMATEUR RADIO CLUB

MINUTES OF GENERAL MEETING 8/20/2008

By Karen, KC2OPX, secretary.

The meeting was called to order by Ed at 5:35 PM.

TREASURERS REPORT – Ed, WB2EAV REPEATERS Gordon, KB2UB

Finances continue to be in good shape. Nothing new to report...

VE REPORT – Bob, W2ILP NET REPORT- Zack, WB2PUE

There were 8 applicants. Four passed the Thursday night net on 745 was short.

Tech exam. Two upgraded to Extra. One The 330 was good.

failed the Tech exam. One failed the General

exam. 5 VEs were AB2NT, KA2GVD,

KA2RGI, KC2OPX and W2ILP.

OLD BUSINESS

Ed reported that there was a meeting of the Northrop Grumman Recreation Club asking for a budget.

We have applied for some money.

NEW BUSINESS

Our September meeting will be a picnic at Marjory Post Park in Massapequa, starting at 5:00PM..

Frank Fallon is scheduled to be our guest speaker. Dave, AB2EF will bring the charcoal.

PROGRAM

For our October meeting we plan to have “Lenny the Weather Man’ for our guest speaker. Bob W2ILP has volunteered to will try to obtain a list of ham radio speakers in our area from the ARRL.

The meeting was adjoined at 6:30PM

GARC NETS:

40 Meters: 7.289 MHz at 7:30 AM EST Sundays.

2 Meters (via repeaters): 146.745 MHz (-.600)at 8:30 PM EST Thursdays.

145.330 MHz (- .600) at 9:00 PM EST Thursdays.

[Tone for both repeaters is 136.5 Hz] (ARES/RACES) Mondays

MEETINGS

General Meetings of the GARC are held on the third Wednesday of each month, starting at 5:30 PM. The meetings are usually held at the Ellsworth Allen Park in Farmingdale. Driving directions and maps can be obtained from http://www.mapquest.com It is suggested that the GARC Web Site be checked to be certain of meeting location, which may change after this newsletter is distributed. Board meetings are held eight days before the General Meeting.

GARC WEB SITE

The web site of the GARC can be found at http://www.qsl.net/wa2lqo/ Webmaster is Pat Masterson, KE2LJ. Pictures of GARC activities, archives of newsletters, roster of members, and other information about the GARC may be found there.

INTERNET LINK OF THE MONTH FOR INTERNERDS

I learned about this month’s internet link from Bill Munsil, K1ATV of Mesa, Arizona. Bill has specialized in amateur television (ATV). I am a member of a ham radio Internet chat group for Mensans, and it is there that I became familiar with Bill’s ATV work. He recently introduced the group to the following link:-

http://www.batc.tv/

Don’t miss this link. Its address is short enough to easily enter and thus easy to get to. If you are not familiar with streaming video presentations, just remember to do the following. Slide the cursor up the narrow triangle on the right side of the bottom of the display to get the audio. Click on the “play” triangle on the left size. Click on the box that will enlarge the video for full screen viewing….and enjoy.

This video was produced by GW hams who have become expert TV communicators. It shows their antennas, their work in field conditions, their club meeting and their hamfest… all in Wales, UK. The presentation is well narrated and the ham radio hobby, as well as the specialized TV hobby, is explained in a non-technical manner. Humor is injected by the XYLs of the hams who meet in a coffee clutch (not really coffee but tea with milk and cookies). One of the XYLs admits that she does not remember her hubby’s call sign although she had put it on his birthday cake! It reminded me of many British comedy sit-coms…especially “Faulty Towers”.

PUZZLE

Here is another cryptogram:

SFV ZPF LERZWEL RVDX LR KZPLBQX LEFBN ANRVWCRBVWP JCV PUFFGE RVDX LR

GRVGFJD LEFBN LERZWELP. –ORDLJBFN--

Solution to August’s Cryptogram:

NEVER EXPLAIN – YOUR FRIENDS DO NOT NEED IT, AND YOUR ENIMIES WILL NOT BELIEVE YOU ANYWAY. --ELBERT HUBBARD—

EDITORIAL

I sometimes find it difficult to decide what I will write about in a cover article for this newsletter. Of course my task would be eliminated if any club member would submit a usable original article. I also know that I can’t talk about controversial politics here, although I may be quite opinionated about recent events. Thus I stick to historical events that relate to radio and especially ham radio. My facts can now be verified by Google research. This month’s cover article was inspired by an article in “QST” which told about the Edison effect. The “QST” article reminded me about that subject so I decided to try to tell the rest of the story here.

I am now trying to find guest speakers for future meeting programs. It seems to be more difficult than it was in the past. There isn’t anyone who now retains a local speakers list. To top this all; I recently learned that Tom Carrubba, KA2D, our NYLI Section Manager has resigned.

Again I want to remind all about this month’s picnic meeting. I hope to see you all there..

73,

w2ilp (Igniting Light-bulb Plates)

CQ de WA2LQO

SEPTEMBER 2008

VOL. 81, NO. 9

EDITOR

Bob Wexelbaum W2ILP

(631) 499-2214

[email protected]

CONTRIBUTING WRITERS

All the members of GARC (we hope!)

CQ de WA2LQO is published monthly by the Grumman Amateur Radio Club for its members and friends. Send articles and amateur equipment advertisements to: W2ILP. Articles may be sent by e-mail or postal mail. They can be in MS Word format or simply in plain text. Articles will only be edited when permission is granted by the author.

ELECTRONIC SUBMISSIONS

For insertion to the WA2LQO website, information may be sent to Pat Masterson.

Pat Masterson’s e-mail address: [email protected]

Ed Gellender’s e-mail address: [email protected] or [email protected]

GRUMMAN AMATEUR RADIO CLUB OFFICERS FOR 2008

President Ed Gellender WA2EAV X02-14 516-575-0013

Vice President Gordon Sammis KB2UB Retiree 631-666-7463

Secretary Karen Cefalo KC2OPX 631-754-0974
Treasurer Ed Gellender WB2EAV X02-14 516-575-0013

1Yr Board Member Zack Zilavy WB2PUE Retiree 631-667-4628
1YrBoard Member Dave Ledo AB2EF

1Yr Board Member Bob Christen W2FPF

2 Yr Board Member Bob Wexelbaum W2ILP Retiree 631-499-2214

2 Yr Board Member Jack Cottrell WA2PYK Retiree 516-249-0979

Trustee WA2LQO Ray Schubnel W2DKM Retiree

STANDING COMMITTEE CHAIRMEN

Contact VE: Bob Wexelbaum W2ILP Retiree 631-499-2214

Webmaster Pat Masterson KE2LJ Retiree 813-938-4614

GARC VE EXAMS

We are continuing to proctor exams for all classes of ham licenses on the second Tuesday of each month, starting at 5:00 PM.

The present exams are:-

The Element 1 CW exam is no longer required.

Element 2: Technician

Element 3: General

Element 4: Amateur Extra Class

Please Note:- THE EXTRA CLASS Q & A WAS CHANGED AS OF JULY 1, 2008.

The fee for 2008 is $14.00 for all exams taken in one sitting.

Applicants for upgrades should bring their present license and a photocopy of it and know their FRN number.

New, first time applicants should be aware that their Social Security number will be required on their application form, unless they register with the FCC for an FRN. All applicants should bring picture ID such as driver’s licenses.

Until further notice exams will be given at:

Briarcliffe College

1055 Stewart Avenue

Room: Long Beach #5

Bethpage, NY

Briarcliffe, Bethpage is located in a building that was formerly part of the Grumman complex.

All applicants should contact W2ILP to register, so as to confirm location. If no applicants apply, the exam session will be cancelled.

For any information e-mail [email protected] or phone- (631) 499-2214

Study material is available at the web sites of the ARRL

http://www.arrl.org

or W5YI

http://www.w5yi.org

All VECs use the same Q &A pools.

Since the beginning of the VE program the GARC has provided opportunities to take the ham exams monthly, during all 12 months of every year.

Bob Wexelbaum, W2ILP and the GARC VE team.

SEPTEMBER MEETING PICNIC AT MARJORIE POST PARK WITH GUEST SPEAKER ARRL HUDSON DIRECTOR FRANK FALLON N2FF

On Wednesday September 17^th at 5:30 PM we will be having a picnic at Marjorie Post Park in Massapequa. We also are having a guest speaker. ARRL Hudson Director Frank Fallon, N2FF. It should be a really good time. Be there! See President’s message page for directions.

Frank Fallon has recently undergone a sinus operation and we were not assured that he would be able to attend our picnic meeting - but as of this writing Frank has confirmed that he will be there. We are glad to hear that Frank is recovering. Last month Ed related how he was a student at a school where Frank later became a teacher. It’s a small world! Frank and I attended the same radio school…. at different times. It was the Southeastern Signal School of Camp Gordon (now Fort Gordon), Georgia. I had taken the US Army Signal Corp. course for Field Radio Repairman (MOS 1648) at that school first. I had held ham and commercial licenses before I was in the Army so I got through the 6 month course in only 3 weeks. The only part of the course I had to study for was the part on Radio Teletype (RTTY) because it wasn’t covered in detail for license exams and I initially knew nothing about it. I managed to study with a fellow student who was an engineer and a ham. His name was Roy Beck but I forgot his call sign. Anyway I never used RTTY or needed to know much about it until I took the ARRL computer course and used my computer sound card, etc to work RTTY. So what is the coincidence between The Southeastern Signal School (called Tessie Tech by the GIs), Frank and me? The coincidence is that Frank operated RTTY as a ham even before it could be run from a computer keyboard…and that both Frank and I learned about marks, spaces, and RTTY at Tessie Tech.

See you all at the picnic…

73,

Bob w2ilp