W6WLS Rebuild Go Fund Me

Greetings, All, The CZU Fire destroyed the W6WLS repeater and other equipment located on Empire Grade Road.  Here is a GoFundMe site to help restore it: Rebuild the Empire Grade Tower Site, organized by Matthew Kaufman

Please help in any amount that you can.

Becky KI6TBK

October Club Zoom Meeting

John Sisler (KJ6ZL)       “AMATEUR RADIO AND SATELLITE CONTACTING”

Friday, October 16, 7:30PM Don’t miss this excellent presentation by John Sisler (KJ6ZL), illustrating and discussing the art of Amateur radio and satellite contacting.

https://launch.amsat.org/The_AMSAT_Journal

John Sisler, KJ6ZL, The primary person for Satellite contacts during SLVARC/SCCARC Field Day events. This designation ‘just happened’ over time, and has become a yearly thing for what now may be more than ten years running.

“It all began with a simple setup, and hand-operated antenna tracking (In fact we put the antennas up by simply cradling them on a tripod of three poles standing together, like they did with rifles during the civil war.). Someone would read the results of list of calculated satellite positions, and move the antennas manually, while I sat at the radio and tried to make contacts. Since then automation has joined the party and now everything is automated, even the tuning of the radio. The station has improved year after year, and now has become a simple setup to repeat.

Though maybe for next year we could try adding…

So you see, this is how the game of satellite contacts goes. It’s great fun, and sometimes can be very similar to ‘weak signal’ contacts, and sometimes similar to DX pileups. There are some things going one that make it much easier than in the past, and some things that are making it harder. In general I love it, and hope everyone else would join me in playing this game.

For this presentation I plan to discuss the current state of satellite operation, what I am aware of that is coming for the future, and how we can all get on the air. It will be an interactive discussion, and I welcome all questions.”

John Sisler is a BSME, with recent Master of Energy from the University of Auckland. He has years of experience in mechanical design of electronic products, and has recently been concentrating on geology and geothermal energy power production.Edit

The August 21 Club meeting will feature Nate Preston (KM6THA) will present a virtual tour of the new repeater equipment and building upgrades (improved ventilation).  
Richard (K8SQB) will also give a brief presentation on the International L

Jim Koger, N1IPP, now a Silent Key

Many of us will fondly recall our club member, Jim Koger, N1IPP, now a Silent Key.

Ron Skelton, W6WO, telephoned to report he’d received a call from Jim’s wife
Maureen reporting that Jim has passed away after a long battle with cancer
in Massachusetts.  Jim was an active club member and CAKE attender and
maintained his club membership and involvement long after moving from Santa
Cruz to Massachusetts.

73, Cap KE6AFE

K6BJ 2-Meter Repeater Aux Input Panel Temperature and Power Monitoring

Introduction

The recent upgrade to the K6BJ 2-meter repeater includes a new Arcom RC210 repeater controller. The controller has a number of capabilities not currently in use. This document covers the addition of an auxiliary input panel to allow easy connection to the controller’s multiple digital outputs and analog and digital inputs, and the connection of sensors and circuitry to allow monitoring of temperatures and power voltages. Also covered are the controller programming additions needed to make use of the new sensors, and possible future capability enhancements.

Arcom RC210 Connection

The Arcom RC210 Repeater Controller includes on its rear panel one DB-25 connector intended for the connection of peripheral equipment. This connector provides 8 analog inputs, 5 digital or alarm inputs, and 7 digital outputs. (See Arcom Version 3.5 Hardware Manual). To make these connections available for convenient use, we now add a shielded DB-25 cable to bring signals to screw terminals on a 3½ inch panel to be installed at the rear of the repeater rack.  See Fig. 1.

Temperature and Power Voltage Sensing

Circuitry for the connection of temperature sensors and for monitoring power voltages is contained in a small metal enclosure affixed to the auxiliary input panel adjacent to the screw terminal blocks. 

AC Voltage Sensing

AC power from the power grid or the repeater shack’s AC generator is monitored at the AC power receptacle at the base of the repeater equipment rack. A small transformer mounted to the rack panel steps down the voltage and provides ground isolation. Voltage from the transformer’s secondary is rectified, filtered, and scaled to produce a signal between 0 and +5VDC which is proportional to the AC power voltage. This connects to the controller’s AD3 Analog Channel 3 input. Scaling constants in the controller software allow it to report the power as AC volts.

Battery Voltage Sensing

Battery voltage is sensed at the fuse block in the repeater rack. Resistors scale the voltage to the 0-to-5-VDC input range of the controller’s A-to-D converter at AD4. Scaling constants in the controller software allow it to report actual battery voltage.

Temperature Sensing

Temperature is measured using an LM35, an inexpensive IC with an output voltage directly proportional to temperature, varying 10mV/°C. One sensor is in the equipment rack near the Yaesu DR-1X radio, and one sensor is outside affixed to the north wall of the repeater shack. Sensors are powered from the controller’s stabilized A-to-D reference voltage. Sensor current is limited to about 80 µA to prevent errors due to self-heating. Sensor connection is via twisted-pair CAT-5 cable. Small bypass capacitors shunt any RF voltage induced on the cable runs. 

Inexpensive LM35 sensors have an accuracy of ±1°C. Their output is scaled to read degrees Fahrenheit with calibration constants programmed into the RC210. 

Controller Programming

Status Query 

The following query commands are supported:

  1. AC Power Voltage
    DTMF command code: [TBD]
    Repeater response: “AC power xxx volts AC”
  2. Battery Voltage
    DTMF command code: [TBD]
    Repeater response: “Battery xx.x volts DC”
  3. Outside Temperature
    DTMF command code: [TBD]
    Repeater response: “Outside temperature xx degrees” [requires custom DVR track]
  4. Rack Temperature
    DTMF command code: [TBD]
    Repeater response: “Inside temperature xx degrees” [requires custom DVR track]

Alarm Conditions

AC Power Loss:

If the AC power drops below 102 VAC as measured by the RC210 Repeater Controller, the following actions occur:

  • The repeater transmits once, “AC power out. AC power xxx volts AC.”
  • Repeater courtesy tone changes to [TBD]
  • Repeater ID switches to CW only at 20 wpm. ID ceases when the repeater is unused.
  • After every 10th transmission, the repeater appends the tail message, “AC power out.”

When AC power is restored to at least 108 VAC, these actions occur:

  • The repeater transmits once, “AC power on. AC power xxx volts AC.”
  • Courtesy tone and repeater ID is restored to normal operation.
  • Tail messages cease.

Low Battery Voltage:

If the battery voltage drops below 12.8 VDC, the following actions occur:

  • The repeater transmits once, “Battery xx.x volts DC.”
  • The repeater courtesy tone changes to [TBD]
  • Repeater ID switches to CW only at 20 wpm. ID ceases when the repeater is unused.
  • After every 10th transmission the repeater appends the tail message, “Battery xx.x volts DC.”

If the battery voltage drops below 12.4 VDC:

  • The repeater transmits once, “Battery low. Battery xx.x volts DC.” This repeats as a tail message after every 10th transmission.

When battery voltage recovers above 13.0 VDC, these actions occur:

  • The repeater transmits once, “Battery xx.x volts DC.”
  • Courtesy tone and repeater ID are restored to normal operation.
  • Tail messages cease.

High Temperature:

If inside temperature exceeds 100°F, the following action occurs:

  • After every 10th transmission the repeater appends the tail message, “Outside temperature xx degrees. Inside temperature xx degrees”

Tail messages cease when inside temperature falls below 96°F.

Future Enhancements

In addition to the items planned above, we could consider adding a number of additional enhancements to the system.  

Some low cost enhancements include:

  • Repeater shack door sensor
    Allow a status inquiry to determine whether the door to the repeater shack is open. Possibly transmit a message when the door opens or closes.
  • AGM battery monitor
    Monitor the voltage of the AGM battery bank currently used for the UHF repeater.
  • Exhaust fan status
    If we decide to install a thermostatically controlled exhaust fan, the controller could report whether the fan was on or off.
  • User changeable periodic announcements.

At the (sometimes considerable) cost of additional hardware, the controller could support:

  • Davis Instruments Weather Station
    The RC210 software includes turnkey support for the Davis Vantage Vue and Vantage Pro Weather Stations. Prices start around $190. (You never know when someone will need to know the barometric pressure at Upper Delaveaga Park.)

UHF Backbone
Connect the repeater to a backbone UHF repeater. This would allow full equality with KJ6FFP/W in Watsonville and (maybe) W6JWS in Bonny Doon.

K6MMM Field Day 2020

  • Adaptation A pair of end feed antennas, HF station Photo: K8SQB

SCCARC K6MMM Field Day 2020 MOVIE

Greetings, All,My friend, Ms. Dorothee Ledbetter, just completed the edited video of this year’s Santa Cruz County Amateur Radio Club and San Lorenzo Valley Amateur Radio Club Field Day 2020 at Lago Lomita Vineyard.  I think she did a marvelous job, and hope you all enjoy the video.

Becky, KI6TKB

24-minute version (24.38, upl. 7/30/20)
https://youtu.be/rOWcwiVng08Edit


Inspiring Amateur Radio Video

From The Radio Society of Great Britain

LOCAL AMATEUR RADIO OPERATORS KEEP NEARLY- 90-YEAR ANNUAL TRADITIONAL NATIONAL EVENT ON THE AIR DESPITE COVID-19 CHALLENGES

At a time when most of our treasured annual events have been cancelled due to COVID-19 restrictions, local amateur radio (HAM) operators found a way to keep this year’s June 27-28 Field Day event up and  on the air.  

Since 1933, with silence only in 1942-1945 due to World War II, the American Radio Relay League (ARRL) has promoted Field Day as an emergency-readiness exercise and as a way to promote amateur radio to newcomers.  Normally this event, held on a weekend in June, is a hard-working  beehive of people, shoulder-to-shoulder, raising portable antennas and sharing radio microphones and potluck dinners with an extended invitation to the public.  

However, when COVID-19 restrictions threatened to eliminate all of that, members of the Santa Cruz County  Amateur Radio Club and San Lorenzo Valley Amateur Radio Club were determined to find a way to hold this year’s June 27-28 event safely.    

Traditionally the two local Clubs join forces, often including the UCSC Amateur Radio Club members.  This year, the UCSC students did not participate, because most of them had left town when COVID-19 shut down the Campus.  

“When we looked at everything that had to fall away in order to make the event happen safely, things got simpler,” said Kerry Veenstra, the event coordinator and whose radio call sign is K3RRY.  No sharing food at a big public potluck.  No huge and complicated antennas that require lots of people working closely together to raise.  No open invitations to the public.  

Instead, the antenna configurations were simple, and the types of equipment used were reduced.   People signed up for short shifts of radio operation so that no one sat side-by-side.  Everybody wore masks, sanitized their stations often, and brought their own food and water.  The public visited the site via a Zoom conference tour.    

From a hill top vineyard deep in the Santa Cruz Mountains, the radio operators exchanged hundreds of messages with others from throughout North America over a 24-hour period, using power from solar panels and quiet portable generators.   This year, some people in the County set up smaller radio stations near their homes as well, and joined the Field Day event remotely.  

It was a great success.  

Ensuring that this year’s  Field Day was not cancelled was important not only because the radio operators treasure the event and it’s rich history, but also because the community service events that normally provide good disaster communication training for the radio operators who volunteer for disaster public service were all cancelled.  These include the Big Sur International Marathon, the Sea Otter Classic, and numerous local cycling and triathlon events.  

Amateur radio figures heavily into emergency communication plans throughout North America, and especially in Santa Cruz County, which becomes easily isolated in natural disasters.  Santa Cruz County has an unusually high number of licensed and active radio operators.  They are ready and waiting to lend well-trained assistance when called upon by local Emergency Operations staff in the next emergency or disaster.  

For more information, please visit: San Lorenzo Valley Amateur Radio Club: https://www.slvarc.org/   Santa Cruz County Amateur Radio Club: http://www.k6bj.org/


Field Day Surprises

Don Taylor
K6GHA

To say we live in interesting times would be an understatement. However, to have participated in Field Day 2020 underscores amateur radio’s ability to adapt to conditions, while building and maintaining social contacts.

Our story began about a month before field day. Our host asked a small group of local hams if we would be interested in operating a 1A station “with power” in the Santa Cruz Mountains in California. 

My immediate reaction was a mix of emotions. First, I’d never operated a station over 100 watts, and this station would be running around 550W, what an opportunity! Second, with concerns of COVID-19, how difficult would setting up and operating a Field Day site? And Last, how well did my skills fit into the team being assembled.  As Paul Harvey used to say, “And now, for the rest of the story”. I couldn’t pass on this event. 

Field Day planning is an art. And even more so when it’s done with a minimum crew, when you are erecting a tower, and balancing 3 antennas (a tri-bander for 10-15-20m, 40m wire Yagi, and an 80m dipole (plus a beverage)). I’d recommend that you start simply, and build up to taking on a complex effort. However, it helps to learn from someone who is experienced, a visionary, and at times a MacGyver. Our host, Bob Wolbert (K6XX) happened to be all of those. Having worked with him in the past, I knew whatever plan he had in mind would work. Also I knew, with the minimum crew, it would be a Field Day where ‘all hands on deck’ was expected.

Friday morning, just 24 hrs. before the event, we arrived on site and started the assembly of the tower on a 90+ degree sunny day. First adding the boom and spreaders for the 40m wire Yagi to the tower, and then attaching the 4 element triband Yagi. The 40ft tower was then raised and guyed. The 80m dipole would be hoisted up into position, as we flew ‘the colours’ on the tower.

https://lh3.googleusercontent.com/pw/ACtC-3fJJoJsqwQcriHK2f-7BOL9VarGV2pFLJFkSvPjV3mw8wUduQsiDe68qE7--Mr4aqd9kGoTNR2ZAa_p3F7TmhebkdSSuNlWtw1Uu6rRf_EI083-R8YI_87FlwQB7IUvkuZAPB8d9pLSu5xfK0Zaxv1X=w998-h860-no?authuser=0

Friday afternoon we began the station setup and configuration. We knew we wanted to cover the basic modes of Sideband, CW and Digital, so we needed to ensure the configurations and PC software was correctly installed and operating. Tom Stollar (KW6S) was our Digital and VHF/UHF captain. Reed Cotton (N1WC an ARRL VE and instructor) and I (K6GHA) were focused on Phone operation. Our host (K6XX), whose name and call you may remember from the 2018 WRTC, was again the MacGyver focusing on CW. Bob also operated all other modes, and configured the Elecraft K4. We were one of a handful of test sites for the new Elecraft K4. I could only think ‘how cool is this?!’.  

https://lh3.googleusercontent.com/pw/ACtC-3ez7nJHf-rI_pKSNsw9diJr7Yi-naHP99MD01s-xcSFCYVYZ7oj8xWTSYxCJSbstl2VMh4YEaPN6O2R2MY7Xz-xuJqE4L6Gc3P0ISFJ14-7KMqDE04Sbr3UpHi--GL7-U0kbWE9NAVx5gKy3b_ZFQFV=w997-h526-no?authuser=0

The station set up proceeded without a hitch, and within five hours we were ready to copy the ARRL W1AW CW bulletin at 5PM Pacific. All went mostly according to plans. In my limited experience, an uneventful set up for Field Day can only be attributed to good pre-planning, team communication and coordination, and preparedness for the unexpected. Safety, contingencies, and backup resources are all a part of that preparedness. 

Saturday morning greeted us with a sunny and dry day in the high 80’s, and a growing excitement about the event ahead of us. Little did we know what fun Mother Nature planned for this year. 

We established the schedule of operation. The four of us, ensured we would be using our own headsets, addressed ‘best social and sanitizing practices’ for the open air screened mesh tent we were using, and finalized the systems setup for digital operations. The clock ticked to 18:00 UTC and it was about 86 degrees and calm. We were ready. N6IP 1A SCV (Santa Clara Valley). 

https://lh3.googleusercontent.com/pw/ACtC-3eZWxOgoFS247_lAxYgq5mJTuyCfydR5V4gTJ4P99Ov5EsuDiqtfdgrYYymiKVlIi9ImUxVrpdmUyoABkYC-fjEh1vGgykOC3MeJ1F518bXB30h_6Ef41B2PZviurKdjTuzwuI73i7co-oNYeH4KPJL=w997-h526-no?authuser=0

The operating schedule was set up to guide the team though an introduction to the Elecraft K4, build station and trade-off techniques and awareness, and to ensure mode configurations were operating efficiently. The first ½ hr. made sure we were working on all bands, antennas, and modes, and acted as a guided tour for the new K4 touch screen features. You may ask why we didn’t do this prior to the start of Field Day, and the simple answer was timing and the availability of the Elecraft K4. However, getting up to speed went smoothly. After the first half hour, each operator took a one hour shift to test their understanding, and become familiar with the radio and band conditions. The number of 1D stations was noted quite quickly in response to our CQ’s. 

I started my one hour shift and was amazed at the clarity and ease of listening with the audio from the K4. Even in a pile up I was able to sort most calls. I have a K3, and the improvements were noticeable. As I got used to the radio, my efficiency improved and just towards the end of my first hour I had settled into a fun rhythm and rate. It also was my first time using a beverage antenna and diversity reception. Having a different receiver in each ear was a little distracting for me at first. However it really opened up possibilities for operational improvements at my own home station. As Bob said “It made my 40m rate much better, listening to the Yagi in my left ear and the Beverage on the right. Reduced repeats down to nearly none.” 

It gave me a greater appreciation of what Elecraft has produced. My focus on making the next contact was so intense it took a tap on the shoulder to be told my time was up. I was having a lot of fun! I reluctantly unplugged and completed the operator change. We then settled into our standard 2 hr. shifts of operation throughout most of the rest of the event.  

Dusk fell on the West Coast and we were treated to a fire red reflection of the setting sun off the high forming wispy clouds. 20m was still active. As the sun set, there was a noticeable change in the weather. The wind had increased to about 10mph in gusts, and the temperature was beginning to drop. I retreated to my sleeping bag for a quick nap before my 1am shift was to begin. 

I awoke, excited for my shift, and was glad to have brought a jacket. The winds were now about 10 to 12mph steady, and the temps had plummeted into the high 40’s as I started. In the next 4 hrs, the weather didn’t improve. At the end of my 2hrs, Bob checked in and asked if I could do another shift. I couldn’t answer fast enough… SURE! He took over for 30 minutes, while I took the time to warm up a little bit, grab my sleeping bag as a wrap against the cold, and relieved him to pick up again on 40 and 80m. In that short time the wind started to really gust. It was over 15mph and sometimes higher. I could tell it was blowing because the fan in the tent, which was turned off, was freewheeling on its own and at a good rate! The temp was now down into the low 40’s. Not sure of the wind chill, but with an open tent layout, and expecting warmer conditions, I know I made a sight for Tom who arrived at 4am. He quickly retreated to get a blanket to use as his wrap, and we completed the shift change. 

As dawn broke at our elevation of 2600 feet, we were in the clouds. A thick marine layer of fog and dampness moved in as the winds abated. Band conditions improved, by 9:30am the clouds were breaking, and the temps were now on the rise again. The warmth and band activity was appreciated. 

There were no issues heading to the finish line of the event, and we finished with Bob at the helm closing Field Day out with CW. 11am arrived, we shut down the radio, took a breath, and began the station takedown. 

In our case, the station teardown was as uneventful as the set up. Within about an hour and a half, the tower was lowered, and the antennas removed. A quick, and much appreciated, snack provided by Bob’s wife Miki boosted our spirits and motivated us to the final clean up. Ropes, guys, and lines wound up, beverage and 80m dipole packaged up, 40m Yagi, Tribander, and tower disassembled and ready for put away.  

With planning, flexibility, and a little MacGyver’ing, N6IP logged contacts on all HF bands for which we had antennas. Everyone had a great time!

N6IP Field Day Contacts Logged: 
– 612 CW
– 649 SSB
– 132 Digital (FT-4/8)
for a total of 1393 contact, and score of 2137 points.

Bonus Points: 
100% Emergency Power – 100
Media Publicity – 100 (Film Crew for Elecraft K4)
Field Day Message – 100
Web entry – 50
Total Bonus350

Total Score plus Bonus – 2487

Even in these strange times, challenging conditions, and an added surprise from Mother Nature, Field Day 2020 was all, and more, than I expected. Saying I had a great time doesn’t capture the full essence of working with a great team, on a great station, and running with power. 

Having that additional power was a treat I won’t soon forget. As we broke down the station, Bob reminded me we were running an Elecraft KPA500 amp for Field Day, and said with a wink “you could even go another 4dB up in power, to 1500W someday.” As a Low Power operator, I am reminded often by Bob, “More power to you”. I can’t wait for an opportunity at full power!

As we departed, the team agreed that our operation fulfilled everyone’s expectation of the most important part of Field Day, great FUN. 



A Digital Field Day

I’ve enjoyed running the Field Day Digital effort for the past few years.
The issue was getting N1MM to work smoothly with the digital modes programs.  I achieved 70% sucess each year.
This year, I was determined to have the software running smoothly.  I had a few days off.  I read every article.  Set up the software and tested it continuously.  At a point, I set aside this effort to gather my field day supplies.
Before the field day event, WSJTX had an update.  I thought this might be something to help with Field Day.  The version went from 2.1  to version  to 2.2.2.
At Field Day, Gary was “Running” and made some 30 contacts that logged well.  I took over and tried search and pounce and the software crashed.  
Six hours of field day op time was wasted finding a solution.   Emails from across the country confirmed that WSJTX 2.2.2 was not “Ready for Prime Time”.
We used WSJTX with JT Alert to avoid dupes.  Jason used his skills to run up nearly 400 contacts.
Originally, I blamed N1MM for our failure.  In fact, it was the WSJTX update that caused the failure this year.
I have some angst over my continuing failures to get a smooth-running software suite .  My problems were seen in other operations around the country.
In the field, I find that simple, robust hardware and software are the key to sucess.  We have achieved this in our hardware.  I will spend some time this year finding software solutions that are “Bomb Proof”.
I wish to thank Kerry for his organizational skills.  Gary for his help setting up the station and running the station.  I wish to give thanks to Jason for making the most out of our Digital effort , using makeshift software, assembled at the last moment.
Craig Harlamoff   N6SBN    EOF


How the National Bureau of Standards helped make “radio”

This was originally published as “NIST’s Role in the Early Decades of Radio (1911-1933)” on the National Institute of Science and Technology’s blog, Taking Measure…….Dan

Even if you weren’t able to watch the recent Super Bowl on TV, you could still listen to the play-by-play commentary on the radio. But radio does more than just broadcasting sporting events or playing music. It plays a major role in emergency response, navigation and science.

The word “radio,” however, didn’t become part of our regular vocabulary until 1911, and it happened thanks in part to J. Howard Dellinger, a radio scientist at the National Bureau of Standards (NBS), the agency that became the National Institute of Standards and Technology (NIST). This came about when the second International Radiotelegraph Conference was being planned in London, and a professor sent Dellinger a paper that he was going to present to the conference for review.

At the time, “wireless” was used as the term for radio communication, especially by the British. However, NIST was charged with revising standards in preparation for the conference, and Dellinger suggested that the professor use “radio,” which was already becoming a popular word in the U.S., instead of “wireless.” The professor agreed, and the word “radio” went on to become the universally accepted term.

Dellinger not only played a role in popularizing the word “radio,” but he also played a role in the first radio work done at NIST. A commercial company asked NIST to calibrate a wavemeter, a device developed by one of its engineers that measures electromagnetic waves like those of radio. Dellinger was known as the wireless expert and took on the project of calibrating the first radio instrument at NIST.

A New Type of Radio Receiver

But for radio to become mainstream, it first had to be commercialized, which began with its introduction into households. However, the challenge was building a radio set that used the electrical current, called alternating current (AC), which powered lights, fans and kitchen appliances when plugged into wall sockets. The predecessor to this technology was developed and patented by two researchers, Percival D. Lowell and Francis W. Dunmore, at NBS in 1922. They called their invention the “mousetrap.”

Percival Lowell with his patented radio set powered by alternating current. Credit: NIST

The “mousetrap” was a receiver for a radio amplifier that could run on AC. This was considered a breakthrough because at that time radios were only able to be powered by direct current (DC) provided by batteries. These batteries were bulky and heavy, had to be charged from time to time and were considered dangerous because of the acid used in them. The researchers’ prototype meant the radio could be used in homes without causing damage and with the same performance quality.

Lowell and Dunmore filed two more patents together for other innovations, and for the “mousetrap” they sold the rights to the Dubilier Condenser Corporation. Little did they know that, because there was no uniform policy on patents issued to government employees, their actions would result in more than a decade of litigation over who legally had the rights to the patent.

While they were tied up in court, the Radio Corporation of America (RCA) developed its own model of the AC radio in 1926. Its model later became the first AC-powered radio sold to consumers.

Flying by Radio

During the early years of flight navigation, NIST was doing research to assist pilots while they were flying and landing. Pilots needed three things to get their bearings when flying “blind,” meaning it’s foggy, too dark or too cloudy to see. They needed to know the longitudinal position, altitude and speed of the aircraft, which were all achieved by various beacons installed in the plane. The remaining issue was that there were two frequencies the pilot constantly had to switch between the frequency that the Department of Commerce used to send weather information to planes and ships, which sometimes caused interference for pilots, and the frequency the radio beacon operated on, which gave altitude and other information.

Dunmore created a prototype, but Harry Diamond, a radio engineer who joined NIST in 1927, completed the device, called the radio guidance system. Diamond solved the problem by developing a separate device that allowed for voice communication to the pilot without receiving any outside interference from ships’ radios.

A Curtiss Fledgling, a trainer aircraft developed for the U.S. Navy, was equipped with the device, and flight tests were performed between NIST’s experimental air station at College Park, Maryland, and Newark Airport in New Jersey in foggy weather. After a series of successful tests were performed, the device was turned over to be used by the Department of Commerce in 1933.

Praise From a Famous Inventor

While mostly intended for serious users, some of NIST’s journals and publications were popular with the public. One such book, titled The Principles Underlying Radio Communication, covered topics such as elementary electricity, radio circuits and electromagnetic waves and was also published as a textbook for soldiers in the U.S. Army. The famous inventor Thomas Edison received a copy from NIST and wrote a letter thanking the first director, Samuel W. Stratton, for publishing it, saying it was “the greatest book on this subject that I have ever read.”

As these and other examples show, NIST had a significant influence on radio research between 1911 and 1933. However, NIST’s radio work didn’t end with the first blind landing. NIST would continue to contribute to the field leading up to and during World War II, and research continues to this day in areas such as 5G, public safety communications and spectrum sharing.

——————————

ABOUT THE AUTHOR

 Alex Boss is a general assignment writer in the NIST Public Affairs Office and covers standard reference materials (SRM). She has a B.S. in biology from Rhodes College and an M.A. in health and…


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2019 Holiday Luncheon