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In message , Mark S. Holden
writes BobS wrote: I live on the 2nd floor of a condo (no outside antennas allowed) with a random wire (60') from my R8B, out the window, and thrown over a tree branch. No separate feedline; just one length of thin wire from radio to tree. As expected reception is compromised with excessive noise. Can anyone advise if there is a way to reduce the noise? Can't have a ground rod. Don't want to move. Would an active antenna be an improvement or a waste of money? I do understand that I'm never going to have a Good setup, but just looking for some improvement. Thanks...Bob Remove MYHAT for email response An impedance matching transformer might help. Here's a link to simple plans for making a 9:1 transformer: http://www.kc7nod.20m.com/new_page_1.htm I can't see a 9:1 transformer making one scrap of difference. Its normal application is to enable you to locate an antenna remote from house (and hence from sources of electrical interference), and bring the signal back the receiver via screened (coaxial) cable. The purpose of the transformer is to help minimise the 'pot-down' of the antenna signal on those frequencies where the antenna impedance is a lot higher than that of the 50 or 75 ohm coax. There really should be a good ground connection at the antenna-transformer-coax interface. If there isn't, the 'ground' will via the braid of the coax. However, unless the coax braid can be grounded, it will effectively be part of the antenna, and you are likely to get interference pickup on the coax. Things might be a bit better than simply bring the antenna wire directly to the radio, but I wouldn't count on it. An active antenna would probably be a better choice, but needs investigating. -- Ian |
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