Posts

The Heathkit AT-1 Amateur Radio Transmitter. Post #319.

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It's time for a little nostalgia, thanks to the Heathkit AT-1 Amateur Radio Transmitter. Jeff Tranter does an excellent job of explaining how the AT-1 works and demonstrates some of its capabilities. This 3-tube transmitter, coupled with a simple dipole or vertical antenna, gave newly licensed novice operators many hours of enjoyable contacts. The rig was well-shielded and offered fairly good TVI suppression. Once a novice passed the General License Exam, he/she could plug in a VFO and an AM modulator. I've only used an AT-1 once in my 37-year amateur radio "career"-a rig belonging to a fellow amateur operator on Hawaii Island back in 1977. Even in that year, the AT-1 was well out of production, having been originally introduced around 1953. As Jeff warns all would-be restorers, special care must be taken around this rig, since high voltage may be present on the chassis. Tranter recommends removing the old 2-prong cord and replacing it with the 3-prong plug

Simple Ham Radio Antennas: A Random Wire Solution for an "interior shack". Post #318.

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Here's another great antenna idea for those amateur radio operators limited by HOAs and CC & Rs.  Stan's "stealth antenna" is simple, cheap, and easily deployed for both home and portable use. When I first became a novice licensee back in 1977, I used a similar antenna at a rented home near the Honokaa High School campus. The community was located along the Hamakua Coast of Hawaii Island and had an excellent clear water shot to the mainland United States and Europe. The only difficulty I had in those days was the lack of a decent back yard to support a dipole or a radial system for a vertical antenna. I did have a tall Norfolk Pine Tree in the back yard which I "recruited" to support the end of my random length wire. I used an 85-ft/25.91 meters length of #22 AWG wire for the radiating element and a 17-ft/5.18 meters length of #22 AWG wire for the counterpoise. My crude antenna was a variation of the once popular "Zepp" antenna used on the

Simple Ham Radio Antennas: How to make a cheap and easy 4:1 balun. Post #317.

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Most of my HF antennas are fed with 450 ohm ladder line going into a 4:1 balun and then continuing on to my Drake MN-4 antenna transmatch with  a short length of RG-8 coaxial cable. Although I have an excellent 4:1 balun in the shack (a W9INN 4:1 balun), I felt the need to have a spare just in case my primary balun fails to work. This article by the Wiltshire Man fills that need. I spent a leisurely hour or so in the shack assembling this simple device. I'm not a mechanical genius, so I just took my time watching the video and putting the unit together. Once I finished this project, I tested it with my 80 meter inverted vee. I was running slightly below 50 watts output from my Ten-Tec Argosy II transceiver and experienced no overheating in the balun, which was connected between the 450 ohm ladder line and the Drake transmatch. The balun worked without any problems on 80, 40, 20, 15, and 10 meters. Following the test, I removed the homebrewed balun and put it in my "go

Simple Ham Radio Antennas: Dipole and Inverted V Basics. Post #316.

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Sometimes, simple is best. In the case of amateur radio antennas , an easily constructed dipole or inverted v antenna will get you on the air quickly at minimal cost. Dave Turlock 's video is a basic, well-explained tutorial on how dipoles and inverted v antennas work. Dave covers construction techniques, mounting of the antenna, and tuning of this simple, yet effective antenna. For monoband use, use a good grade of 50 ohm coaxial cable for your feedline. If you wish multi-band capability, use 300 ohm TV twin lead or 450 ohm ladder line for the feedline. This type of feeder must be used with a balanced antenna tuner or fed into a 4:1 balun and then connected to your antenna transmatch ("tuner") with a short piece of 50 ohm coaxial cable. Either way, your new dipole should be mounted as high as you can without endangering your safety. My last inverted v was designed for 40 through 10 meters by cutting the radiating segments to my lowest preferred frequency (7.

Simple Ham Radio Antennas: Delta Loop Antenna 40 through 10 meters. Post #315

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I found this fascinating article by SV1CDY while I was searching for some multi-band loop antennas . I've used full-wave loops in the past and found them to be easy to build, portable, and cheap. I duplicated SV1CDY's design without resorting to the 56.7 uH coil, since I had enough space in my backyard for a full wavelength loop cut for 40 meters (7.088 MHz ). Like SV1CDY, I used some #18 AWG speaker wire for the feedline and connected that line to a W9INN 4:1 balun and then, using a short piece of RG-8X coaxial cable with UHF connectors, I attached that assembly to my Drake MN-4 antenna transmatch. For my version of SV1CDY's short loop, I used #12 AWG house wiring for the loop, three ceramic insulators to support the loop, a 33-foot/10.06 meters MFJ telescoping fiberglass mast, some prepositioned wooden stakes and nylon rope to tie off the bottom of the delta loop, and a 6-foot/1.82 meters wooden stake to keep the feedline off the ground until it reached the 4:1 b