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Showing posts with label Antennas. Show all posts
Showing posts with label Antennas. Show all posts

Thursday, January 4, 2018

Part Two - Getting my Amateur (Ham) license and getting on the air.



Then I started my career in Public Safety. Starting out I was a Dispatcher. So, I used a radio a lot. But, it was push the button on the console or activate the foot switch, no real interaction with turning knobs and dials. However, all the radios have vacuum tubes in them. One of the base radios that worked in the 40MHz range was a five foot tall cabinet. That cabinet generated a lot of heat.

Then I went into the field division and had a little more interaction with the radio. We had a squelch control (now squelch control is mostly programmed into the radio), turn the switch to change frequencies and the switch to choose which repeater that you wanted. The mobile radios at this time were a “hybrid” in that the receiver was all solid state, but the transmitter still had one tube (though not a glass envelope tube) in the final Power Amplifier. The unit fit in the trunk and was large and heavy. Of course, some of the cars still had radios in the trunk that required a dynamo to run. When you keyed the microphone (held PTT switch) the dynamo started, and it sounded like a jet taking off. After the dynamo hit peak, you could transmit.

Then we got fully solid-state radios. Not much smaller in the trunk, the control heads were larger but that was because the siren\Public Address board was part of the control head. We still had a squelch control and the knob to change frequencies and push buttons to choose the repeater that you wanted. These radios still had crystals in them that were “cut” to the proper frequency. The crystals were housed in metal heater containers to make sure that they would work at the proper frequency.

As time went on, I got acquainted with a gentleman that ran the radio repair shop for a large construction company doing work in the area. He had been in law enforcement, and volunteered with the local EMS and volunteer Fire Departments. He was not into Amateur (ham) radio, just commercial and Public Safety. From him I learned a lot about radios. With his guidance I took several radios that had been donated by a federal agency to the local search and rescue organization and replaced the crystals with new ones and retuned them to work in the public safety band area. I learned how repeaters worked, that a frequency split was necessary, that most were activated with a CTCSS tone. That changing or adding a new repeater or changing the CTCSS tone on a repeater meant a lot of work, as all the radios that accessed that repeater had to be modified. I even started my own sideline business of installing radios in Public Safety vehicles. It was not unusual to see an ambulance, police car or fire truck in our carport while I spent days or weeks installing radios. A lot of the installations had to have control heads or at least microphones in the front and back of the vehicle. I learned a lot.

Then a promotion came, and I was assigned to administration. Part of that job was management of the radio system and the fleet. It was about time to change the radio equipment. It was getting a little ancient and though it still worked well it was time to upgrade. So, with all the background and knowledge gathered through all the years of radio interaction, we redesigned the system. We relocated repeater sites, added a few and made the conversion to synthesized radios. No more crystals. We used a computer to change the frequencies. We also added Digital Voice Protection, or scrambling to the system. This was a headache as the code had to be created and then loaded into each radio. But, it worked well.

A change of jobs led me to yet another radio adventure. This time it was to assist in the planning and implementation of a county wide narrow band VHF simulcast system. This system would carry traffic for numerous law enforcement, fire and ems agencies. What a project.

Tuesday, December 12, 2017

Ham Radio - Getting the license - getting on the air - Part One

Back in the mid 60’s, I would listen to my cousin W7ZQR transmitting and receiving on his ham radio every time that we would visit, which was frequently. I was fascinated by him talking across town, across the state or across the world to another ham operator. “W7ZQR, W7 Zebra, Queen, Roses transmitting in the City of Roses.” The knobs and dials and switches were amazing, how would anyone know what to do. I decided then that I wanted to be a ham radio operator. 
But, in the 60’s you had to know Morse code. There was the problem. Cousin W7ZQR provided us with a straight key with a battery and light bulb so that I, along with my brothers could learn. He also taught us how to build a simple wire antenna, using wood insulators, made out of wood from a fruit crate, and connecting it to a crystal radio. The antenna was strung between a tall cedar tree and a large oak tree. It was probably 20 feet off the ground and close to 100 feet long. The feed line was just another piece of insulated (if I remember correctly) wire that went from the cedar tree (which was the closest) to our bedroom. I came through the window and connected to the crystal receiver. The receiver was the basic crystal set with the “pick” that you “probed” the crystal with and the enameled coil wound on what looked like a toilet paper roll, that you moved the copper contact across to change frequencies. With a set of headphones, we tried to tune in the world. I honestly can’t remember if we (or I) ever heard anybody or not.

Fast forward to the early 1970’s and the Citizen Band Radio was becoming the thing to have. By that time we were in Boy Scouts, then Explorer Scouts and eventually a Search and Rescue group. I remembered that we have an uncle who lives in Texas (we lived in the Pacific Northwest) that was into radio stuff. My brother and I wrote him a letter and asked if he had a radio. Imagine our surprise when a wooden box came with a single channel Hallicrafters (think it was) with the “magic eye” tube on the front that when you transmitted came down from the top in a “C” shape and full modulation would give you a full green circle. We began to “build antennas” for this. Course not knowing anything about antennas or antenna theory, we probably blew up the radio and never knew it.
We then got a “mobile” CB radio from someone that we knew. It had a Cinch Jones six pin power plug on the back. We apparently gave our friend the wrong information, so when we put the radio in the car (1963 Corvair), it was wired backwards and we ended up melting a large portion of the wiring harness in the dash of the car.
There were various other radios that came and went, most were not worth much when we got them and certainly not worth anything when they left us.