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#1
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SW77 With Outdoor Antenna
I have been using the Sony ICF SW-77 receiver either with the whip antenna
or a variety of indoor antennae for the last several years. In all of these configurations, I did not have an earth ground available to use with the antennae (I was an apartment dweller). Now my circumstances have changed and my wife and I find ourselves moving into a suburban house with a sizable back yard, apparently ready made for setting up a permanent longwire antenna with a good earth ground. My guess is that the antenna that I can put up will be 100 to 135 ft long. I plan to bring the signal in to my radio on 50 ohm coax, and I am planning to use a grounding block (gas discharge?) similar to those used for CATV installations. My question is, will I notice a significant improvement with this system? I am mindful of the possibilities for signal overload, but I plan to run the gain control in its "MEDIUM" or "LOW" settings unless I am interested in listening to difficult stations. I am particularly interested in hearing tropical band stations in Africa, Central/South America, and the Pacific. |
#2
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My general impression of modern receivers is that they're already really
sensitive. You get more signal and equally more noise from a bigger antenna, so you're not ahead once you're above the internal noise of the receiver, which is what is low in modern receivers and so you don't see much advantage once you're beyond the minimum antenna. On the other hand, you get increased intermodulation and overload from other signals you're not meaning to listen to, and that's something modern receivers are not designed to suppress, mostly. So it's likely you'd need a preselector to drive down the unwanted overloading signals; possibly you'll hear more then on the frequency you're tuned to. Alternatively your outdoor antenna can be a low noise one, and give you an advantage you don't get indoors. Ie. designed not to pick up signals and noise you don't want to hear. Whether this is dimmer noise from neighbors or power pole insulators breaking down, or some local broadcaster, depends on your situation. I use active antennas outdoors and phase them to produce nulls, chiefly on MW. Nulling SW signals that are not locally produced is difficult by phasing though, unless you have a huge number of elements to produce an extended null. -- Ron Hardin On the internet, nobody knows you're a jerk. |
#3
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Ron Hardin wrote:
My general impression of modern receivers is that they're already really sensitive. You get more signal and equally more noise from a bigger antenna, so you're not ahead once you're above the internal noise of the receiver, which is what is low in modern receivers and so you don't see much advantage once you're beyond the minimum antenna. On the other hand, you get increased intermodulation and overload from other signals you're not meaning to listen to, and that's something modern receivers are not designed to suppress, mostly. So it's likely you'd need a preselector to drive down the unwanted overloading signals; possibly you'll hear more then on the frequency you're tuned to. Alternatively your outdoor antenna can be a low noise one, and give you an advantage you don't get indoors. Ie. designed not to pick up signals and noise you don't want to hear. Whether this is dimmer noise from neighbors or power pole insulators breaking down, or some local broadcaster, depends on your situation. I use active antennas outdoors and phase them to produce nulls, chiefly on MW. Nulling SW signals that are not locally produced is difficult by phasing though, unless you have a huge number of elements to produce an extended null. A passive pre-selector is almost mandatory when using a good external antenna with a sensitive portable like the SW77. I had to do this with my '2010'. Otherwise the bands were full of spurious signals (intermod's). -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
#4
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I live in a penthouse on top of a six-floor building in middle of
noisy San Juan Puerto Rico and I have tried using an outdoor wire antenna on my SW 77 strung across my terrace. I must say that the whip is a whole lot better because it doesn't amplify all the snaps, crackles and pops. Try using the outboard wire antenna and extend it out from a window. I do that sometimes and let it hand down. I find that works great. I am able to receive Indonesia, Western Sahara, Brazil, Peru and New Zealand from my QTH. I think a regular wire antenna with ground and all overloads this overly sensitive rx. Let's us know how you make out. |
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