"Are You A Wizard"
Jerry Wellman, W7SAR
This article appeared in the April 2000 issue of Worldradio
Too many years ago to count, I was living in Laramie, Wyoming and became the local Civil Air Patrol squadron's communications officer. My first, assignment was to figure out a way to communicate with our squadron's pilot during air search missions. I don't recall the pilot's name but he flew a bright red Stinson. These were the days before low-cost VHF-FM and our options were limited.
My impression of radio was that of a small, elite group of technical wizards who accomplished amazing things behind locked doors. It was OK to approach a radio wizard with a question, but you'd better have done your homework because one question was all you got. If your question was accepted by the wizard, you would be invited to learn. If not, you would be summarily dismissed, never approach the wizard again.
Anyway, the Stinson pilot had recently upgraded the plane's avionics to a new navigational rig and had the old radio tucked away in his hangar. In the interest of public service, he donated the old radio, a Narco "Simplexer" to me so we could establish air-to-ground communications. He also gave me an old World War II vintage carbon microphone. Neither he nor I had much radio experience, but we figured that only an "aircraft" antenna would work for the radio, so he talked another pilot into donating an old antenna to the project.
My radio experience at that time was limited to Citizen Band rigs, but I was undaunted by this foray into aviation radio. The rig had the usual knobs: volume, squelch, channel select, and tuning. There was a transmitter indicator lamp and it looked pretty straight forward. The Simplexer had a plug on the back that had the power, microphone, and speaker connections and soon the old Narco's tubes were glowing and sounds were coming from the speaker.
There were several unmarked connectors on the back including a Motorola jack and an RCA connector. From my limited radio experience. I figured the Motorola jack was the antenna connection (after all that's what my AM car radio had) and deduced that the RCA jack was for audio because every other RCA jack I'd seen had been used for audio. So we drilled a hole in the trunk of my car to attach the aircraft antenna (essentially a threaded, quarter-inch rod). We connected the coax and discovered we could hear the local Unicom aircraft traffic. Not wanting to run afoul of the FCC which we were sure monitored every frequency waiting to pounce on illegal operations, we decided not to test the transmitter yet.
The Narco radio was crystal controlled and I had to order a very expensive crystal for 123.1 MHz which was the search and rescue frequency. It took many weeks, but finally the crystal arrived, we plugged it into the radio, and we were ready for a test on our licensed frequency. I drove to the hangar and we warmed up the plane's radio. It was time for the big test. I carefully keyed the microphone and gave the CAP call sign. In the Stinson, the pilot heard the transmission and responded, saying it sounded good. We were excited and ready for action. We could hardly wait for the next search mission.
I spent a lot of time in the car listening to aircraft traffic, anticipating the opportunity to use the rig during our next search. As I recall, the mission came a month or two later and I volunteered to set up communications in the search area. Our communications included a three-channel CB radio (one channel was the CAP's 26 MHz channel), a Heathkit HW-18 HF-SSB radio, and the newly installed aircraft radio. All were tube radios which meant the car would have to be running while we operated and we didn't have a mobile HF antenna so I had to stretch a 100-foot dipole between trees.
Soon our squadron aircraft flew over and I could hear him call in our command post. l answered but he didn't respond. The transmit light would come on, and we tried again, but no response. All of our other radios worked fine, and we received calls from the aircraft, but they couldn't hear us. After the search we retreated to the hangar to test the gear again. It worked fine in the hangar.
In desperation I decided to approach a local electronics wizard. I drove to his shop, carefully knocked on the door, and was wide-eyed as the door opened and I could gaze at all those wires, tubes, and radios. I stammered out my dilemma and Lloyd (l recall only his first name) smiled and said he'd help me out. I was elated for the wizard had accepted my question and plea for help. In the next several hours, Lloyd showed me a watt meter and an SWR meter. He took the time to explain how they worked and drew pictures and diagrams on paper scraps as he taught me some basic trouble shooting.
He was not familiar with aviation radios, but assured me the principles were the same with every radio, demonstrating on his Amateur Radio gear and my CB gear. It appeared that there was no signal coming out of my Narco radio, for none of the meters moved when we keyed the rig. We could hear the signal on his monitor, but as he explained, without an indication on the meters, there was not enough signal to reach far. He then asked a fateful question: "Do you have an instruction manual?" Why hadn't I thought of that! I didn't have the manual, but soon found it among all the junk in the hangar.
With the manual and schematic, it didn't take Lloyd long to discover that the Narco radio required two antennas, one for transmit and one for receive. That RCA jack I thought was for audio was for the transmit antenna! Lloyd helped me install a second antenna and that Narco performed for many years on a number of search missions. I learned a great deal about radios that Saturday afternoon and Lloyd was happy to answer my questions for the year I lived in Laramie. That was a highlight of my year, befriending a radio "wizard."
The moral of the story is what I see happening in public service communications today. We're seeing some highly sophisticated trunked and data systems that require a "wizard" to install, troubleshoot and keep running. Users will focus on their specialty, for example, as peace officers and 9-1-1 dispatchers using data terminals. They won't be able to check for a loose coax or a blown fuse because the system will be complex enough to require a wizard. I'm not suggesting Amateur Radio operators tackle support for such a complex system, but I believe as systems become more complex, the need will increase for a system that is flexible and can integrate diverse resources during times of emergency. And that system is Amateur Radio.
Let's consider a scenario where an emergency requires linking fire and police services with a hospital in a mass casualty event. The fire and police operate an 800 MHz trunked system, the hospital has a VHF system, and the school buses used to transport the injured have radios on a variety of systems or no radios at all. It would be great for everyone to be on the same system. If you had enough spare police and fire personnel, you could have them travel with the buses or operate from the hospital, but you see the problem. They're needed at the scene and not as communicators.
You would also need to address the needs over several days and the ability to support an operation over a multi-jurisdictional area. The strength of Amateur Radio is the ability to link agencies and relay traffic. Operators can set up stations at the scene, at the hospitals, in the buses, and with other agencies not usually included in an overall system.
Let's say for the sake of argument that every agency in your county has a trunked system. You would also have to assume they were supplied by the same vendor so their systems would be compatible and let's presume that a common frequency were available for coordination. Can you imagine the confusion when fire, police, bus drivers, utility vehicles, hospitals, and many agencies attempt to share a common frequency? What's urgent to one will not be urgent to another. Hospital terminology, will be confusing to bus drivers. You might have a single dispatch point attempting to control the chaos, but the traffic would be overwhelming.
My premise is that public services agencies do not have the resources to gear up for large-scale, multi-jurisdictional events that are temporary in nature. Their normal day-to-day needs require significant resources and large events simply overwhelm their systems. I recently listened to a vendor presentation where he explained how agencies can share a common trunked channel. And it sounds great during the sales pitch. It also works fine for coordination on a small scale. I submit that it doesn't work when the yogurt hits the fan.
We can compare the sales pitch to a highway system. The reason we have many roads between destinations is because one road cannot handle every car and different drivers have different needs. A freeway can handle large volumes during normal time but what happens during an accident or storm? You need alternate routes. Some cars are faster and more efficient and built for freeway use. Tractors work great in dirt but are slow on highways. A two-lane road between point A and point B is great until thousands need to travel all at once.
I look at Amateur Radio as the alternate routes during heavy use. Our need is to develop "wizards" that know how to look at a need and respond accordingly. Our people need to know how agencies work and how our systems work so we can link agencies together. Please take the time to show the new operators the ropes. Encourage antenna building parties, tune-up clinics, project building, and all the activities that allow others to learn what goes into making radio work. It's important that Amateur Radio is able to support itself by perpetuating technical expertise. We need people who know the basics.
It's time we develop Amateur Radio "wizards" like Lloyd -- operators who are willing to take the time to teach others the basics and theory that apply to radio. Please take the time to let others know of your willingness to have them learn from you. As you hear someone new on the air, invite them over to build an antenna or volunteer to help them install their rig. Show them what an SWR meter is and how it works. Amateur Radio strength continues to be our technical ability with the basics. Let's ensure the legacy continues.
Until next month, best wishes from Salt Lake City!
--Jerry Wellman, W7SAR, can be reached at P.O. Box 11445, Salt Lake City, UT 84147 or via e-mail: firstname.lastname@example.org
Printed Circuit Boards
Gerry Crenshaw, WD4BIS
In the past, the one thing that stops most people from completing a project is the idea of making their own Printed Circuit Boards (PCB's), especially on a project with any quantity of integrated circuits (IC's). Here is a method of making printed circuit boards that has been refined through time. For those who wish to make a small quantity or just one PCB, try the following procedure on your next project.
To start, you will need:
- an etch resist pen (a Sanford Sharpie permanent marker works well too)
- Copper Board Material
- #60 (.040") drill
- etchant (the Radio Shack etchant works well enough)
- plastic or glass dish (non-metallic) or zip-lock bags larger than the copper board material
- fine steel wool
- two copies of the artwork
1. Start by cleaning the board material with the fine steel wool. This will remove any copper oxidation and allow the etch resist to stick better.
2. Cut the artwork to size leaving about a half-inch border. Tape the artwork to the board material very tightly (use any transparent tape).
3. Drill the board using the taped-on copy as your guide. Drill through both the paper and board material at the highest speed possible. Drill out all the holes with the # 60 drill first. For larger holes, use the #60 hole as a guide hole. Do not attempt to drill a larger hole until the taped-on artwork has been removed. Even a 1/16" drill can grab the paper and remove a large piece of the taped on artwork leaving you to wonder "Did I miss any holes?" The answer has always been YES!
4. Remove the taped-on artwork. If there are any larger holes to be drilled, drill them now. Clean the board again with fine steel wool: this time the steel wool is used to remove burrs the drilling left behind.
(NOTE: by drilling all the holes first you get the correct alignment for transistors and Dual In-Line Packages IC's done first. No guessing later when laying down the traces).
5. Using your second copy as the guide, connect the drilled holes with the etch-resist pen. Allow it to dry, then put on a second coat of the etch-resist. (Note: A Sanford Sharpie permanent marker will work as well as a the Radio Shack etch-resist product and you can buy these in boxes of twelve for club projects. In addition to this, the Sharpie pen points can be trimmed with an X-acto knife to give you different pen widths and shapes.) If you make a mistake, erase the etch-resist with steel wool and try again.
6. Put the board in the etchant (use a plastic or non-metallic dish as the etchant will eat a metallic dish). Constantly agitate the board in the etchant. This takes away the copper and allows fresh etchant to reach the board material. In club situations I have used large (gallon-size) ziplock freezer bags in place of the dish. Use a bag within a bag to prevent leaks and reduce the smell of the etchant. And if you use the ziplock bag method, snip off the sharp, square corners of the board using a pair of wire cutters as a sharp corner can poke a hole in the ziplock bag.
7. This is the boring part. It can take as long as 30 to 45 minutes to get the desired result. Keep on agitating. You must keep it in the etchant until all the undesired copper is etched away.
8. Dispose of the etchant (in an environmentally sound manner) and wash the board with water to stop the etching process. A garden hose outside is good for this job as even a drop of the etchant can permanently mar sink fixtures if not immediately washed off.
9. Trim the board to size with whatever tool you have handy (hacksaw, nibbling tool, etc). I have found that an old discarded paper cutter works quite well.
10. If you want to tin the board, tin it with solder or a tin-plating solution. Now you have a PWB ready for assembly.
11. This same method can be used for making double-sided boards as well. After you have taped one side of the artwork to the board material, drill the registration holes or about four of the artwork holes as close as you can find to the four corners.
Take the second side of your artwork (also a copy) and find the registration holes (the ones you are using to line up both sides) and poke holes through the paper with a straight pin or lead clippings. Place straight pins in each one of the registration holes. Placing the pins in the holes already drilled will line up the second side of the artwork to the first. Bend the pins down to hold the second side in place and tape this artwork down firmly as well. Remove the pins.
Drill a test hole or two to check the registration and alignment of the artwork top to bottom. If the registration is good, drill the rest of the board. If not, adjust the artwork and try again.
When making the copies of the artwork, try to use the same copier. Even the best copier stretches or enlarges the artwork a little, but the small amount that this distorts the image is not a concern if you are laying the traces down by hand.
Printed Wiring Board of even moderate complexity have been made with this method and by amateurs as young as eleven (and a half) years old.
Copyright 1996 Gerald Crenshaw WD4BIS. All rights are reserved.
GRUMMAN AMATEUR RADIO CLUB
MINUTES OF GENERAL MEETING 4/19/00
BY Pete, N2PYV
The meeting was called to order by Pat at 6:45 PM. All present introduced themselves.
TREASURER'S REPORT –
Ted was absent. Pete read the financial statement as reported at the executive meeting. Finances continue to be in good shape.
REPEATER REPORT - Gordon, KB2UB
Gordon will be talking to Bill, N2NFI, and visiting the Hauppaugue site. The Tower at the site remains unsold and probably will remain so for some time because the soil under the tower is contaminated from water leaching from the nearby landfill.
NET REPORT –
The Sunday 40 Meter Net had so-so propagation. The Wednesday 20 Meter Net had only 3 check-ins because there was a retiree meeting going on in the south.
VE REPORT –
Pete read the report presented at the Executive Meeting. There were 3 candidates and 6 VE's present. All three candidates passed an element, but there were no upgrades.
WAG REPORT –
Pat reported that the Company must get out of Plant 5. The building has to be put back in the original shape before the Navy will accept it. When the Navy accepts the building, they will turn it over to Nassau County. It is not sure what the County will do with it. They might sell it because they are hard up for money.
Pat visited the Bethpage Water District Office to discuss installing our repeater antenna on the tower. He was told to write a letter to the Board of Water Commissioners. Pat will write a letter requesting a meeting with the Commissioners.
Northrop/Grumman wants to move our trailer so that they can dig up the earth to remove contamination spilled into the ground from the hydraulic shack. Pat discussed with the Facilities Dept. that since Plant 5 was going to be sold, we would like to move the trailer only one time. Two possible locations were discussed. One was near the guard shack at Plant 14. The other was in an unused parking lot near Plant 1. Facilities will discuss this with management.
Pat read an email that he had received from the Hudson Division of the ARRL. The email stated that 10 states had passed laws similar to PRB-1, which restricts municipalities from imposing tower restrictions on amateur radio towers. There is a bill in the NY Senate, #S7324, that might be expedited if amateurs wrote to Senator Mary Lou Rath, 817 Legislative Building, Albany, NY 12247 (Email: email@example.com). A similar bill is in the Assembly #A9947. You should write to Assemblyman Thomas DiNapoli, 621 Legislative Office Building, Albany, NY 12248 (Email:firstname.lastname@example.org). You should also write to the Senator and Assemblyman from your district.
John Caruso, W2JAC Updated us on the progress of the Grumman Memorial Park.
John, KB2SCS gave an interesting demonstration of Slow Scan Television (SSTV).
In answer to my question last month, who was R. Thompson, W2KPD?, I received the following e-mail:
Hi Dave....just a little note to tell you who the subject of the feature article in the April CQ was. Ralph Thompson was an old timer employed in GAC and also a long time member of the radio club. Ralph was active on most of our nets especially the 40 m net on Sunday mornings. He lived in the Bethpage/Farmingdale area while employed in Bethpage and when he moved out to Mattituck, he transferred to Calverton. That's all I can remember now. Zac 73....
Zac informed us on a recent 2 meter net, that R. Thompson was the fourth Grummie to join the Club. So, he probably was a charter member. -Pat
These two messages answer my question. However, if anyone else has more information I would be happy to see it.
The Editor, KA2FEA