Topband: One wire reversible beverage with 2 feed-lines
Hi, I m trying since 3 weeks to test some reduced size beverages . I have roll 180m of wire on a 20mm PVC plastic pipe at 20cms of the ground of 24m long . Best match with 50 Ohms cable was around 240 Ohms so I've used 7:1 transformer to match. Resistivity of my used wire on total length is 12 Ohms. Actually the Beverage is not load , so bidirectional ,results are nice compare to my EWE , but I planned to do a reversible system on single wire. I saw an article from W8JI in the Communications quarterly , spring 2007 page 103 that it is possible to feed both side of the antenna . So the rx direction of the antenna will change cause system with be load or not on both side. But in this kind of system w8ji write : . termination resistance is made equal to the coax feed line's impedance. The transformer step the termination impedance up to the proper value, just as they step the receiving end's impedance down to match the cable. So if I understand it is better to use some 75 Ohms cable than 50Ohms to lift the termination, so have more effect !!?? May somebody has ever done this system . and can donate own opinion. Thanks in advance. B R 73s Damien F4AZF www.f4azf.com http://WWW.F4AZ.COM _ Topband Reflector
Re: Topband: and KDKA
In recent years many Canadian fulltime AM stations have been shut down on AM and moved over to FM. However they remain notified which is a semitechnical term meaning the Canadian government tells other countries such as the US, which are signatory to treaties, that those facilties still exist. The New Brunswick 700 went off the air several years ago. I think the Alberta is off the air as well. Another source of this kind of information is the AM Pattern Book, published by the National Radio Club. They just published a new edition this year. Bob k2euh Richard Fry r...@adams.net wrote: A frequency search for 700 kHz shows some high power night time licenses in AB and NB. I don't remember if those licenses existed before the downgrade the Clear Channel concept, which I think happened sometime in the 70s or early 80s. Here is a link to a map showing all AM stations on 700 kHz, as of now. _ Topband Reflector
Re: Topband: Topband Digest, Vol 129, Issue 23
Try a large transformer shop. 5kw and up transformers often use it. I've bought round magnet wire from temcoindustrialpower.com, but don't see rectangular wire on the web site, so give them a call for a link. Grant KZ1W On 9/15/2013 9:04 PM, n0...@juno.com wrote: I've just used strips of sheet copper cut with snips for flat wire. I purchased a sheet from a Hobby Lobby store. Their ads usually include a 20% off coupon good for just about any one item at their stores. 73, Charlie, N0TT On Mon, 16 Sep 2013 01:39:46 + (UTC) wa3...@comcast.net writes: I know this may be a little off topic BUT I am looking for some flat wired to wind an edge wound inductor. I am guessing that it needs to be something like an eight of an inch on the narrow side by maybe three eights of in inch on the long or flat side. This will allow my roller wheel to ride on the inside of the inductor to change inductance. Now for the rub. I cant find anyone that makes wire like this. I know it is made because others have made inductors using this kind of wire. Oh and it has to be silver plated if possible. These coils are to be part of a balanced tuner and yes I know I can purchase coils but I want consistency since I am going to build several of these units. Any and all help appreciated. Thanks Jim WA3MEJ http://www.qsl.net/wa3mej/index.htm _ Topband Reflector _ Topband Reflector _ Topband Reflector
Re: Topband: and KDKA
What some broadcaster won't do to get a signal their market. There is an AM station out on pilings in Biscayne Bay or at least there once was. I don't know how it could have survive Hurricane Andrew if it did. But the station and four tower array was put there to avoid interference to a protected Cuban clear frequency and still be able to blanket Miami. The transmitter room was in a sealed container with positive air pressure to keep out salt air. Engineers would arrive each day my boat to make the require on site inspection. I think the power was brought out from shore with an undersea armored HVAC three phase cable. Remember at the time broadcasting was big business or as some in the industry used to call it a license to steal. But today with all the proliferation of FM and digital services there isn't much left for AM except News, Sports, Talk, and Information on the market price of pork bellies. Today anyone with a computer and an internet connection can be an instant broadcaster and be heard world wide. Herb Schoenbohm, KV4FZ On 9/16/2013 7:13 PM, Richard Fry wrote: With respect to U.S. AM broadcast stations, Bob k2euh wrote: Another source of this kind of information is the AM Pattern Book, published by the National Radio Club. They just published a new edition this year. The Check it Out link on the NRC website shows U.S. AM station locations and patterns for 560 kHz. However, the physical location they show for the transmit site of WIND (560 kHz) appears to be in Illinois (see clip below), rather than at the location shown by the FCC for the WIND array -- which is in Indiana, SE of the intersection of I-94 and IN Hwy 912. The FCC coordinates for WIND are 41° 33' 54.00 N Latitude, 87° 25' 11.00 W Longitude (NAD 27). Didn't check for any other errors. http://s13.postimg.org/pcpbguj2b/WIND.gif RF _ Topband Reflector _ Topband Reflector
