Wednesday, February 20, 2019

Women in Radio



Hedy LaMarr

Hollywood Screen Seductress and the Mother of Spread Spectrum Communications


Other than some fleeting familiarity with her films, I first learned about Hedy Lamarr (9 Nov 1914 – 19 Jan 2000) while on a tour of celebrity homes in Palm Springs, CA. She was an Austrian actress, sex symbol and… yes, inventor. Not something usually attributed to screen seductresses.


She started her film career in Austria. When she worked with Max Reinhardt in Berlin, he called her the "most beautiful woman in Europe" due to her "strikingly dark exotic looks", a sentiment widely shared by her audiences and critics.  Friedrich Mandl, her first husband, objected to what he felt was exploitation of his wife. The 19-year old Lamarr had married Mandl on 10 August 1933. Mandl, reputed to be the third richest man in Austria, was a munitions manufacturer. In her autobiography ‘Ecstasy and Me’, Lamarr described Mandl as extremely controlling, preventing her from pursuing her acting career and keeping her a virtual prisoner, confined to their castle home, Schloss Schwarzenau. Although half-Jewish, Mandl had close social and business ties to the fascist governments of Italy and Germany, selling munitions to Mussolini.

In her memoir, Lamarr wrote that Mussolini and Hitler had attended lavish parties hosted at the Mandl home. Mandl had Lamarr accompany him to business meetings where he conferred with scientists and other professionals involved in military technology. These conferences became Lamarr's introduction to the field of applied science and the ground that nurtured her latent talent in the scientific field. She had been an excellent student and attended the best private schools in her youth.

Lamarr emigrated from Austria by posing as a maid, to escape her controlling husband. First she went to Paris, then met Louis B. Mayer in London. Mayer hired her and insisted that she change her name to Hedy Lamarr—she had been known as "the Ecstasy lady" — choosing the surname in homage to the beautiful silent film star, Barbara La Marr, who had died in 1926 from tuberculosis. She received good reviews for her American film debut in Algiers (1938) with Charles Boyer, who asked that Lamarr be cast after meeting her at a party. 

She became a contract star of MGM's "Golden Age”.  In Hollywood, she was invariably cast as the archetypal glamorous seductress of exotic origins. Lamarr played opposite the era's most popular leading men during the 1940s. She appeared only sporadically in films after 1950, and for a time gave up custody of her children as she became destitute. Twice during the 1960s she was charged with shoplifting.


And now the rest of the story… 

Avant garde composer George Antheil (died 1959), a son of German immigrants and a neighbor of Lamarr in California, had experimented with automated control of musical instruments, including his music for Ballet Mécanique, originally written for Fernand Léger's 1924 abstract film. This score involved multiple synchronized player pianos playing simultaneously.

During World War II, Antheil and Lamarr discussed the fact that radio-controlled torpedoes, while important in the naval war, could easily be jammed by broadcasting interference at the frequency of the control signal, causing the torpedo to go off course. Lamarr had learned something about torpedoes from Mandl. Antheil and Lamarr developed the idea of using frequency hopping to avoid jamming: using a piano roll to unpredictably change the signal sent between a control center and the torpedo at short bursts within a range of 88 frequencies in the radio-frequency spectrum (there are 88 black and white keys on a piano keyboard). The specific code for the sequence of frequencies would be held identically by the controlling ship and in the torpedo. It would be practically impossible for the enemy to scan and jam all 88 frequencies, as this would require too much power or complexity. The frequency-hopping sequence was controlled by a player-piano mechanism, which Antheill had earlier used to score his Ballet Mecanique.

On August 11, 1942, U.S. Patent 2,292,387 was granted to Antheil and Hedy Kiesler Markey, Lamarr's married name at the time. This early version of frequency hopping, although novel, soon met with opposition from the U.S. Navy and was not immediately adopted although it was held a closely guarded technological secret by the US military. Lamarr wanted to join the National Inventors Council but was reportedly told by NIC member Charles F. Kettering and others that she could better help the war effort by using her celebrity status to sell War Bonds.

Frequency Hopping was not implemented in the US until 1962, when it was used by U.S. military ships during a blockade of Cuba after the patent had expired. Her work was not honoured until 1997, when the Electronic Frontier Foundation gave Lamarr a belated award for her contributions. In 1998, an Ottawa wireless technology developer, Wi-LAN Inc., acquired a 49% claim to the patent from Lamarr for an undisclosed amount of stock. LaMarr was once again a wealthy woman.

Lamarr's and Antheil's frequency-hopping idea serves as a basis for modern spread-spectrum communication technology, such as Bluetooth, COFDM (used in Wi-Fi network connections), and CDMA (used in some cordless and wireless telephones). 

For more on Hedy LaMarr, watch this YouTube clip:
https://www.youtube.com/watch?v=_rlXHNeQD-s

~ John VE7TI

Sunday, February 17, 2019

The YL Contest Advantage?



A Communicator Reprise...

May 2014


When the idea of a YL only operation for a contest was suggested we considered a smaller contest like a QSO party or something like that. However when it was discussed, the YL's wanted something that would provide more activity so the CQ WW WPX SSB contest was chosen. It would be hosted at VE7IO.

Participants were six enthusiastic YL's, Marcy VE7JT, Christine VA7NLF,  Margaret VE7TJF, Pam VE7PFH, Jeannie VA7QLT and Shirley VE7SHL. We used the call sign VE7JT.
Contest weekend arrived, the schedule was in place and everyone was keen to get going.  We operated two radios in the high power category and happily everything worked well.  We had to leave the night time operation dark, no pun intended, due to family commitments but the early morning and evening operation was covered. 




By time they shut down on Friday we realized that this was going to be a good opportunity for the YLs.  Band conditions were looking very good and everyone now realized that this was going to be a fun weekend. Their best bands were 10, 15 and 20 meters with DX continuing to be heard late in the evening. They did not operate overnight and only had a very short opportunity to work 40m.




Over the past 3 years we have conducted contest training sessions here at VE7IO, VE7FO and VA7XB. The training program has been very successful and we can now proudly list a number of new very good contesters. The program has sparked interest in contesting so when the YL's asked if they could do a YL only contest entry with a training component it sounded like a great idea.  Two of the operators were skilled in the "run" mode and this served to motivate the others as they watched and heard the DX stations calling us.  With such good openings to the DX world, the "S&P" operators were able to log multipliers and  see how their contributions increased the overall score.  Between the "run" operation and the multipliers being added by the "S&P" operators, everyone had a great time and would definitely like to do this again.

Stan VA7NF dropped in on the Saturday to help with station management and plan strategy, the ladies just kept busy on the radios. Stan stayed most of the day and we both enjoyed assisting with band changes and monitoring activity.
For me this was the first time ever hosting an entirely YL group and it was great fun.  We operated Multi/Multi (M/M) which gave us lots of latitude in making band changes and operating in the assisted mode.  As a M/M entry they were nowhere near the big gun stations but the YL's were very proud of their accomplishment, having fun, learning new skills and achieving a reasonably good score.

It certainly seemed an advantage to have an all YL station. Whether it's their voice or their charm (they always added a greeting to their QSO) they always got a great response.

Operating time: 27 hrs. Score: 2,945,743

The graph clearly shows the down times but when they were on the air they did well.




~ Fred VE7IO


Thursday, February 14, 2019

Anagrams


Here's A Few Interesting Anagrams


THE MORSE CODE:
When you rearrange the letters:
HERE COME DOTS
ASTRONOMER:
When you rearrange the letters:
MOON STARER
DESPERATION:
When you rearrange the letters:
A ROPE ENDS IT
DORMITORY:
When you rearrange the letters:
DIRTY ROOM
ANIMOSITY:
When you rearrange the letters:
IS NO AMITY
ELECTION RESULTS:
When you rearrange the letters:
LIES - LET'S RECOUNT
SNOOZE ALARMS:
When you rearrange the letters:
ALAS! NO MORE Z 'S
A DECIMAL POINT:
When you rearrange the letters:
I'M A DOT IN PLACE
THE EARTHQUAKES:
When you rearrange the letters:
THAT QUEER SHAKE
ELEVEN PLUS TWO:
When you rearrange the letters:
TWELVE PLUS ONE
~ Thanks Norm Schmidt


Thursday, January 31, 2019

The February 2019 Communicator



Hot off the presses... 

This month an in-depth look at the new digital mode FT8, plus Amateur Radio News from the South West corner of Canada and elsewhere. You will find Amateur Radio related articles, profiles, news, tips and how-to's. You can download it as a .PDF file directly from https://goo.gl/MoLwKS



As always, thank you to our contributors, and your feedback is always welcome.  My deadline for the next edition is February 20th. If you have news or events from your Vancouver area club or photos, stories, projects or other items of interest from elsewhere, please email them to the communicator@ve7sar.net

Keep visiting our site for regular updates and news: https://ve7sar.blogspot.ca    

~ 73,
  John VE7TI
  Communicator Editor



Monday, January 28, 2019

BC QSO Party 2019



As far as history goes, the British Columbia QSO Party—originally, the BC QSO Challenge—hasn’t got a long one. It began with a suggestion by Scott Robbins, VE7CCY in 2005 to members of the Delta Amateur Radio Society for a casual event that would promote on-air activity in BC. 

The objective was for VE7/VA7 stations to work anyone in the 36 federal electoral districts of BC, as well as the other Canadian provinces, US states and DX countries, and for stations outside BC to work only VE7/VA7 stations. While the rules have been tweaked a bit over the years, the objective has remained the same. 

We hope to hear you on the air!


Thursday, January 24, 2019

The "Best" Random Wire Antenna Lengths


Random wire lengths you should and should not use

A Communicator Reprise: February 2014

Jack Clarke, VE3EED - SK

A random wire is exactly that—a piece of wire that’s as long as you can possibly make it. One end of the wire attaches to a tree, pole or other support, preferably at a high point. The other end connects to the random-wire connector on a suitable antenna tuner. You apply a little RF and adjust the antenna tuner to achieve the lowest SWR. That’s about all there is to it. 

Random-wire antennas seem incredibly simple, don’t they? The only catch is that your antenna tuner may not be able to find a match on every band. The shorter the wire, the fewer bands you’ll be able to use. And did you notice that the random wire connects directly to your antenna tuner? That’s right. You’re bringing the radiating portion of the antenna right into the room with you. If you’re running in the neighborhood of 100W, you could find that your surroundings have become rather hot—RF hot, that is! We’re talking about painful “bites” from the metallic portions of your radio, perhaps even a burning sensation when you come in contact with the rig or anything attached to it.




The random wire antenna is probably one of the least expensive, easiest and cheapest HF antennas to use if you have a tuner and you want to get the "most" out of a length of "random" wire without having to pull out that calculator, doing the math, getting the center insulator built or bought, running the feedline, and all the rest that goes with putting up a more elaborate antenna. All you need for a random wire antenna is some wire, your tuner, one or more supports up as high as you can get them to string the wire from the supports to the tuner, at least one or two insulators and a little time.
One single wire, no solder connections, very simple… all the way from the tuner to the end support. That's it in a nutshell… or is it?

Many hams have tried till they are blue in the face to install the random wire antenna that works on most; if not all of the HF bands with terrible results.
SWR usually is all over the place and the tuner will just not do it's job. You can get good loading and low SWR on sometimes 2 or 3 bands, but one or more of the bands that you want, just will not cooperate with an SWR that can be adjusted with the "tuner".

So after much frustration, down it comes and you go on to a totally different type of antenna… all that time just wasted in your opinion… until now!

We recently found some good information about random wire lengths that you should and should not use.

Jack, VE3EED, hopefully has solved a major headache we all have when we attempt to go thru the trial and error and frustration with getting the random wire to work where WE want it to work.

He knew that in order for the tuner to "see" a fairly low SWR to work within it's range, that the antenna had to be NOT A HALF WAVE ON ANY FREQUENCY that we wanted to use, because a half wave will give us a very high impedance and the resulting high SWR into a 50 ohm transmitter!

So Jack took most of one day, did the math with the aid of his trusty calculator, several cups of coffee and came up with, in Jack's own words…  "Here's the word on random-wire antennae."

Presented for your consideration by Jack, VE3EED, the table (next page) represents half wave lengths and multiples that you  DO NOT WANT TO USE!

You have to stay away from a half wavelength on any frequency. Therefore, we came up with the following numbers to avoid (IN FEET):

These lengths in the table are the culprits that cause all of the trouble when using random lengths.


So those are the numbers above that we have to stay as far away from as possible when building a long-wire antenna. Here they are in order: 16 19 22 26 32 33 38 44 46 48 52 64 65 66 76 78 80 88 92 95 96 99 104 110 112 114 123 128 130 132 133 138 144 152 154 156 160 165 171 176 182 184 190 192 195 198 208 209 220 224 228 230 231 234 240 242 246 247 256 260 264 266 272 276 285 286 288 297 304 308 312 320 322 323 325 330 336 338 342 352 361 363 364 366 368 369 374 380 384 390 396 399 400 414 416 418 429 432 437 440 442 448 455 456 460 462 464 468 475 480 484 494 495 496.

Some of these numbers are too close to squeeze in between them. Here are the final numbers (in my opinion) in green below that would be good for a long-wire antenna: (You may want to make a note of them)

29  35.5  41  58  71  84  107  119  148  203  347  407  423

REVISION NOTE:  James, KB5YN, points out that one of the so-called GOOD numbers was 220 feet. That is the 10th multiple of a half wave on 15 meters. His radio didn't tune up very well on 15 meters. So, having nothing better to do one day, I re-did the calculations going out to 500 feet. That meant calculating all the way to 32 multiples of a half wave on 10 meters. I won't bore you with all that so the first portion of this still only shows up to the 4th multiple. There are so many new frequencies to stay away from, that it gets pretty tricky for the longer wires. However, the list has been revised and is good for wires as long as 500 feet.

Mike AB3AP wrote a small C program that does just what Jack did, but used the band edges.  Because he’s more visually oriented, he then plotted the many overlapping "red zones" and ended up with the page at:

http://udel.edu/~mm/ham/randomWire/

He plotted the results for the U.S. CW band edges for use with his  4 band Elecraft K1 QRP rig.

You will note that when comparing Mike’s results with VE3EED that some of the results are a bit different.




Monday, January 21, 2019

YAK ! Yet Another Knot...


Knots are used frequently in our hobby. From securing loads to securing antennas, a knowledge of some basic knots is very valuable. In this series we feature some common knots for you to practice. This month… 

The Constrictor Knot 

Use this knot to bind ropes, as clamps, or as cable ties


The constrictor knot is appropriate for situations where secure temporary or semi-permanent binding is needed. Made with string or twine it is especially effective, as the binding force is concentrated over a smaller area. When tying over soft material such as the neck of a bag, hard stiff cord is more effective. When tying over hard surfaces, soft stretchy line is preferred. The constrictor knot's severe bite (which makes it so effective) can damage or disfigure items it is tied around.  To exert extreme tension on the knot without injuring the hands, one can fashion handles using marline spike hitches made around two rods.

Constrictor knots can be used for temporarily binding the fibres of a rope (or strand ends) together while splicing, or when cutting to length and before properly whipping the ends. Constrictor knots can also be quite effective as improvised hose clamps or cable ties. 

Noted master-rigger Brian Toss says of the constrictor: "To know the knot is to constantly find uses for it.
















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Women in Radio

Hedy LaMarr Hollywood Screen Seductress  and the Mother of Spread Spectrum Communications Other than some fleeting familiarity wit...

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