Incredible Marconi Magnetic Detector radio WORKING DEMONSTRATION APPARATUS

When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

Incredible Marconi Magnetic Detector radio WORKING DEMONSTRATION APPARATUS:
$1247.00

REPRODUCTION RADIO is one of the most amazing items I have ever listed! This is a complete working setup of Marconi\'s magnetic detector! Under the right conditions you can actually make this unit work and receive radio signals to demonstrate how Marconi used the device early in his radio building times! The Magnetic Detector was the second type of radio frequency detector Marconi used in his receivers. The coherer was the first but it was almost unusable due to its erratic operation and very slow operating speed. The magnetic detector was invented by Rutherford in 1896 and Marconi picked up on it and built a model to see if it would work. It did and he worked at perfecting the design. It was not very successful but quite a large number of them were built and put into service by the British Navy. In this sale you get a complete radio setup that is similar to what was used back in the early 1900\'s by Marconi. (of course he didn\'t have a solid state amplifier to go with his radios, but practicality is practicality!) The radio consists of a high Q antenna tuner which is used to select the stations and match the high impedance of the antenna to the low impedance of the magnetic detector. The magnetic detector is built similarly to one of the early models Marconi built. The function is like a tape recorder in reverse. A permanent magnet places magnetism on a piece of steel wire. The RF signal ERASES the magnetism, like the erase head of a tape recorder. Since the signal is modulated, the strength of the \"erase\" signal varies at the rate of the modulation. The resulting magnetic field left on the wire is at the modulating frequency and is picked up by the output coil. Very clever but not very effective. It works but that is about all. The demonstration apparatus includes a high gain AF amplifier that is used to bring the signal up to the audible level. The original detector used sensitive headphones. Also included in the sale is a reproduction of the FIRST MAGNETIC DETECTOR MARCONI MADE! Marconi was supposedly staying in a hotel room and had very little equipment available so he built the detector in a cigar box using parts he was able to scrounge up. This detector actually does work to some degree but since the movement of the wire is by hand the output is erratic. The two detectors make a wonderful addition to any serious early radio collection. This equipment is not available anywhere else. One other person has build and sold magnetic detectors on but it did not include the support equipment necessary to demonstrate it. Here you get the entire setup and if you have a good outdoor antenna you can actually pick up radio stations using the equipment. It does take a good outdoor antenna at least 50 feet long to get enough signal. A youtube video of this equipment working is at http://youtu.be/4CAxWoKD-fw. In the sale you get the entire setup shown in the photos. I will also include enough antenna wire so you can string up a long antenna to try to get it to work like in the video. Due to the very large amount of work building this equipment the reserve is somewhat higher than my usual but the price is certainly very reasonable for what you are getting. This is the only one available ANYWHERE and I am not going to build another one so if you want this amazing piece of equipment for your collection make sure you offer accordingly. There will not be a second chance ever again. NO OVERSEAS SHIPPING AVAILABLE ON THIS ITEM. USA-CANADA ONLY. SHIPPING TO CANADA WILL BE HIGHER THAN THE AMOUNT SHOWN BELOW.