This is my first time posting here, so 'Hello'. I have a 25 gallon terrarium that I have had to redo 3 times due to mold and most recently mushrooms. It is my first terrarium (I always pick hard projects). Anyway, this forum has been so helpful for me, and the information about the fan was the most helpful. I had planned to get a CPU fan and follow all the splicing directions, until I came across a small 12 volt fan at a website that I order stuff for my cats called Drs Foster and Smith (see link). It is an 'Aqualight Cooling Fan Kit' by Coralife. (They have a couple of other options, too.) It's a 3 1/8' fan, and it has a 12 ft. power cord. It's about $19.00. It doesn't have variable speed, but creates a gentle breeze and is very quiet. I just used wire to attach it to the screen cover I use. I hope this info is helpful to someone. P.S. You'll find the fan in the Reptile section under Habitat Accessories. Here is a link that might be useful: Drs Foster and Smith

There are an infinite number of conditions that can cause TVI (Television Interference.) One common source is Line Interference which results from transient voltages on the 110v AC power supply. Another common cause is Broadband RF interference. Any condition or device that produces a spark generates broadband Radio Frequency interference. Common sources of broadband RF interference are electric motors such as those used in small handheld power tools or small kitchen appliances. Normally Broadband interference does not travel very far from the source, but the actual distance would depend upon the power of the source. While a small motor spark may only effect TV or Radio for 50 to 100 feet, an Arc Welder can produce TVI for a city block or more, while lightning can cause TVI for hundreds of miles. Television is broadcast by means of Radio Frequencies and each channel requires 3 separate frequencies, 1, Video(image) 2. Chroma ( color or grayscale) 3. Audio. The specific frequencies range from 54mghz to nearly 900mhz. In turn, there are hundreds of other bona fide Radio Services that operate on frequencies within that band, such as 6 meter Amateur Radio (54mhz), Military communications frequencies (54mhz, 88mhz 100 mhz) Aeronatical Navigation and communications 100mhz) FM Broadcast Radio (88mhz) and an infinite number ofmedical and industrial control or process frequencies found throughout the television Spectrum. One of the most notorius sources of TVI is bootleg Citizens Band Radio operartors. Whenever a transmitter produces a signal it also produces harmonic signals, which are even multiples of the desired frequency. All radio transmitters are required to have spuriou emission filters to prevent passing the harmonics, however, Federal communications commission regulations prohibit operating a citizens band radio with more than 4 watts input to the antenna. In order to increase their operating range many CB operators clandestinely aquire Amatuer Linear Amplifiers to boost their output power up to as much as 1500 watts. Amateur Radio Linear Amplifiers have very high quality spurious emission filters, however when the filters are in place the amplifier will not work on CB radio so the bootleg CB'ers simply bypass the filters with little to no regard for what interference it may be causeing to other services. CB primarily operates at 27mhz, therefore the first harmonic of CB is 54mhz which happens to be the exact frequency for channels 2 through 5 of TV. TV is also subject to a number of atmospheric conditions which primarily occur in summer. Under some very unpredictable weather conditions we get a phenoninon known as tunneling. In a sense the signal gets trapped between two thermal layers in the atmosphere and is carried for hundreds of miles further than normal. In Ham radio we really look forward to that condition because we can then have a short intercontinental communication on frequencies that would normally be limited to about 300 miles, but for TV it creates a differenct problem. Because the number of available fequencies is limited TV stations 350 or 400 miles away may be assigned on the same frequency as your local station. Under normal circumstances neither ones signal would reach the other, but when tunneling occurs the signals from one station can travel further than expected and interfere with another station on the same frequency. Normally TV signals will not reflect off the ionosphere so TV is basically limited to the RAdio Horizon, which is the optical horizon from the top of the antenna plus 25%. Normally broadcast TV antennas are tall enough to provide about a 75 mile radius from the transmitter. Under some very rare circumstances a TV signal will go up to the E layer of the Ionosphere and be reflected back down in what is known in radio as Skip. When this occurs on TV it causes a ghost image as the primary image is received directly from the station while the bounced image, which must travel a much further distance arrives at the receiver slightly behind the main signal and produces a second ghost or echo image on the screen. Ghost imaging also occurs if you have high moountains of buildings on the downstream side of the signal in relation to your house. You receive the primary image but some of the signal goes on past you and is reflected back causing the ghost image. Normally if you have a fringe area antenna that is directional (on a rotor) the antenna will have sufficient Reflector elements to prevent reflected images. Tree leaves and foliage can have a very dramatic attenuating effect on Radio and TV signals. Normally in summer when the trees have full foliage the received signals are much weaker than they are in winter when trees are bare. On windy days the rocking motion of the trees will cause substantial variations in received signal strength. There are a couple inexpensive things you can do to reduce TVI. First, take your antenna lead in wire and wrap about two to three feet of it in a tight coil about 6" in diameter and tape it together. That will form a simple RFI (Radio Frequency Interference) inductive trap. You can buy a TVI filter at most Radio Shack stores. The antenna wire is conneted to the filter then the filter is connected to the TV. They are relatively inexpensive and require no power or special installation technique. R.Rinard General Class Amateur Radio Operator FCC call sign KC-8-UXZ

Inteference problems are a pain to diagnose, but the good news is that in just about every case the cause can be located. Since your inteference problem is recent you should look for changes that may have occured in and around your home recently. Also, since hte interference affects sets connected to both inside and outside antennas it is safe to rule out cable and ground issues, atleast as far as the antennas go. Since the inteference also affects all channels, it is rather unlikely that weather conditions alone are to blame. Weather conditions typically will either 1.) attenuate distance signals making them noisier or blanking them out completely, or 2.) allowing distant signals on the same channel to travel farther thus causing inteference to nearby stations. While #2 could still be a likely cause, I'm thinkin something electrical is to blame. The questions I normally as are: 1. Have you purchases/installed/connected any electronics, appliances, computers, ANYTHING electric around the time the inteference began? 2. To the best of your knowledge has any of your immediate neighbors done the same in regards to new electrical equipment. 3. Look for cause-effect relationships. Does the inteference start when someone dries their hair, uses an electric shaver, does laundry, etc. 4. Any new construction nearby? Power tools, especially arc welders can cause electrical noise from longer distances, sometimes ranging from hundreds to thousands of feet. 5. Probably not applicable down there, but electric heat and water heaters if they develop a problem can cause inteference too. There are other tips, but I think you get the idea. If you still get stuck, don't hesitate to call one of your local tv stations and ask for some guidance. Make sure you ask for someone in the engineering department, they are used to dealing with these issues on a regular basis. Best of luck! - Steve

I went back and re-read your message, and realized that the problem is with both AM and FM. 1. Move the radio to other locations around the house 2. Try external (not outdoors) antennas 3. Make sure that the electric ground rod near the electrical meter (outside the house) has been properly installed, and that the clamps are tight around the rod, and the electric box. Also, find out from an electrician if the ground wire should also be clamped to the plumbing in the house. I have no idea if this is a code requirement, but my house was built with the breaker box grounded in a "Y' type of connection. Finally search "AM radio antennas" on the Internet. Here is one (cut & paste): http://www.abc.net.au/reception/radio/am_antenna.htm