Date
1 - 11 of 11
Another silly (?) question.
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FenDrifter
Firstly Happy New Year to all! Okay, more newbie help required. I was about to make up a long wire aerial when I realised I wasn’t certain how to do it. I’ve bought a 3.5 mono jack to which I want to attach a single core insulated line. I think it’s obvious I connect to the pin end (central core) of the jack, but what I don’t know is whether or not it matters if it shorts out to the shield?
Any help appreciated Drifter |
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Paul Blundell
What radio is this for? Paul Firstly Happy New Year to all! Okay, more newbie help required. I was about to make up a long wire aerial when I realised I wasn’t certain how to do it. I’ve bought a 3.5 mono jack to which I want to attach a single core insulated line. I think it’s obvious I connect to the pin end (central core) of the jack, but what I don’t know is whether or not it matters if it shorts out to the shield? |
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Tony Germanotta
Don’t let it short out. The other leg on an input plug connects to the radio’s ground, so a short will ground the long wire and make the antenna useless. Also, be careful. Some radio front ends can’t handle the strong signals from a long wire. At best, they will overload and put phantom stations all over the dial. At worst, the static voltage that builds up on the wire thanks to wind and dry conditions can blow out the RF input transistor. There are various work arounds for each situation. Diodes that shunt the static to ground before the input jack, transformers that allow only the signal to pass. Even a light bulb in series shunted to ground that acts as a sensitive fuse. Do a little Googling for options. Long wires are wonderful in areas without a lot of noise, but will pick up and deliver all the radio interference in your neighborhood too. That’s why most folks reserve them for DXpeditions and rely on loops at home, they tend to be less sensitive to manmade electrical noise because they work using the magnetic component of a radio wave. And long wires are potentially dangerous when there is lightning about. Don’t think simply unplugging it from a radio will protect your home. Remember, that bolt is jumping thousands of feet through the air, a couple additional inches in your shack isn’t going to stop it. Properly set up and in quiet conditions, a long wire can be magic, pulling stations in from around the world. Have fun exploring the possibilities. But protect yourself and your gear too. Have a great 2022. On Jan 1, 2022, at 7:31 AM, FenDrifter via groups.io <essexmarshman@...> wrote:
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Hi Tony
Many thanks for such a detailed and informative reply! I’ve clearly got to be more sure of what I’m doing here, and in answer to Paul’s question the beast I’m making this for is my Tecsun PL-330. I was intending to use this hanging out of my bedroom window, but may now keep it for country trips. I did see this YouTube clip of which I’d appreciate an opinion: https://youtu.be/WjCFLG0DHOo Am I right in thinking that the lower ‘earth’ lead is connected to the plugs sleeve. If this is clouding the issue please tell me to forget for now, I can take it! As usual any help greatly appreciated Drifter |
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Tony Germanotta
Drifter, no problem. We all started out needing basic help at some time. The video you referenced is useful. When you talked about a long wire, I thought you were hunting medium wave stations. A wire to get those stations would be very long indeed, with the best results often on wires that are hundreds of feet long. For shortwave stations, the wave lengths are shorter, hence the name. And a random wire of 20 to 30 feet can do wonders on a portable, especially if you can get it out the window and away from light dimmers, aquarium heaters and television sets. Portable radios are designed to be super sensitive so they can use the inefficient whip as a source. Antennas have lots of electronic rules but often work despite them. I find that to be the most fun. Folks have used bed springs and rain gutters as antennas. I have a metal frame around my shower doors that works just as well as an outdoor wire so long as no noisy appliances are running Once we were on a dxexpedition with thousands of feet of wire strung along the dunes of North Carolina’s outer banks. One of our party arrived after dark and dumped a tangle of wire onto the porch next to our meticulously laid antennas. His heap somehow captured everything we heard, including Indian and Indonesian local stations during daylight — probably by acting like a transformer to our antennas. But the rule books wouldn’t have predicted this. So try stuff. Walk around your house. Believe it or not, your whip might work much better in one room. Get a short piece of wire and put clips on both ends. Try attaching one end to the whip and the other to a cold water pipe, if your home is old enough to use copper. Run your wire outside the window. 30 feet would probably be the most that radio could handle without overloading. Sometimes, less wire is better, improving the signal without addding to the noise. Especially if you have powerful radio station towers nearby. A small metal tape measure can be used as an antenna, just extend it as far as helpful and connect it to the radio with that wire with clips. And try a counterpoise, like the video suggests. A ground counterpoise is vital when you are trying to transmit. It may not be as important on receiving. But it could help with fading. You can even cut a dipole for the band you are most interested in. That uses two wires of the same length to offset fades, and when resonant to a frequency, it actually amplifies the signal and reduces the noise. There are lots of books on antennas. And YouTube videos too. Just remember, with radio the best antenna is still reliant on conditions. If the bands are dead, no antenna will open them up. And certain bands work best under darkness, when the sun can’t mess up the ionosphere. More folks get frustrated with shortwave by trying to find stations during the day on a band that will come alive after they pack it in. Good luck. It’s a fun journey. All these signals are constantly flying by us unnoticed until we get a radio and antenna to capture them. On Jan 1, 2022, at 6:11 PM, FenDrifter via groups.io <essexmarshman@...> wrote:
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FenDrifter
Hi again Tony Drifter |
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Tony Germanotta
Sorry I missed your reply, I was on the road. Yea, it’s fun to play with radio. Richard Feynman started his Nobel winning physics career as a kid fixing neighbors’ tube radios in New York City. He was fascinated by the idea of radio signals from all over the world just passing by his head as he walked down the street unaware. At the end of his life, he tried to get to Tuva (off limits to Americans during the Cold War) to see the famous throat singers he had once heard on shortwave. Never made it, but his daughter did. Feynman was one of the fathers of atomic energy and the guy who figured out that cold from escaping gasses had shrunk gaskets and doomed the space shuttle Challenger. He remained a tinkerer all his life, thanks to the curiosity that radio inspired. Experiment and try all sorts of things. You likely won’t be the first to do them. Just be safe. Radio can’t hurt you but electricity can, both out of what you call the mains and from on high during storms. So can climbing stupid things to get away from interference or in hopes of a better signal. Have a great time with the hobby. Each band has its secrets and attractions. And it’s always changing. I got hooked while trying to listen to baseball games well beyond where the signal was intended to travel. My wife bought me a shortwave radio thinking that would help. That Christmas night I turned it on and found HCJB in Quito Ecuador broadcasting a show for DXers. I couldn’t believe I was listening to another continent and people talking about a hobby that was all about such a thing. That was four decades and way too many radios and antenna experiments to count. I hope you have as much fun. On Jan 2, 2022, at 4:30 AM, FenDrifter via groups.io <essexmarshman@...> wrote:
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DX Pedro
Thanks for sharing Tony! :) // pedro andrade On Tue, Jan 4, 2022 at 3:17 AM Tony Germanotta <germanotta.tony@...> wrote:
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FenDrifter
Hi Tony I’m still in the learning stage, and the biggest and most important thing I’ve learned so far is how atmospheric conditions affect reception! |
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Tony Germanotta
Yea, he was a character. Wish I could’ve met him. The atmosphere makes it all happen — or not, depending on lots of things. Different bands react differently to the changes, although weather is usually not an issue, unless there are thunderstorms causing noise. The sun pretty much drives it all, with some frequencies working well only in the dark when the atmosphere settles down and reflects like a mirror Others bounce around the world during the day despite the solar agitation. Then those same bands can die off and come alive during different phases of an 11 year solar cycle. The good thing is when the high bands disappear, the lower ones might be enhanced. The best reception can be when your location and the station you’re trying to hear are in the dark or the grey line as darkness comes. And don’t forget, radio takes the shortest path, which could be over the poles. An old fashioned globe is great to visualize that. Enjoy your journey. On Jan 9, 2022, at 10:43 AM, FenDrifter via groups.io <essexmarshman@...> wrote:
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FenDrifter
Thanks Tony!
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