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Reviews Categories | Ham radio kits | Ramsey Electronics SM100 Signal Magnet Receive Antenna Help

Reviews Summary for Ramsey Electronics SM100 Signal Magnet Receive Antenna
Ramsey Electronics SM100 Signal Magnet Receive Antenna Reviews: 5 Average rating: 4.8/5 MSRP: $$90.00
Description: This antenna responds only to the magnetic field of the desired station and ignores the electrostatic field where most interference is found. It does a remarkable job pulling in stations lost down in the noise of power-line crud, fluorescent lamp buzz and light dimmer hash. Plus it's very directional, able to null strong stations on the same or nearby frequencies! Designed to cover the AM broadcast band, but includes details on building for any frequency range up to 15 MHz; it works gang-busters on Shortwave. Works indoors or out, contained in rugged PVC pipe with a single RG-59 coax cable connector. Operates with up to 500 feet of coax cable (you supply) between antenna assembly and control box (size: 5" x 5 1/4" x 11/2"). Includes all parts, matching case set and pre-cut PVC materials. Operates on external 120 VAC power adapter that is included. Antenna is 9 1/2" x 9" long, L-Shaped 1" PVC pipe with end caps.
Product is in production.
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N0TLD Rating: 4/5 Feb 17, 2019 10:48 Send this review to a friend
Fun to make and use  Time owned: more than 12 months
I loved building Ramsey kits for many years, and this one was probably my favorite build, and favorite to use. I gave it a 4, 'good', because it is not truly 'great' -- it works well but it is not the most sensitive ferrite antenna I own, and its nulls are not quite balanced. But it does work and if you can get it outside away from noise sources, it can indeed garner you signals you didn't hear before. Building it was a challenge but I enjoyed every moment of it. I would love to get another kit now!
NS5F Rating: 5/5 Jun 27, 2016 05:38 Send this review to a friend
Outstanding performance in a small footprint  Time owned: more than 12 months
Years ago I purchased several of the SM-100 for use in a broadcast station to monitor the primary EAS station in my market. Since the station was located in a high-rise office building in a large urban area (Dallas) receiving AM signals were difficult at best. After construction I mounted the antenna in the technical operations center in the middle of the building and was astonished with how well the antenna worked. In addition to bringing the MW station way out of the noise floor the ability to null local noise sources was invaluable. Later I purchased several for use at home for MW DXing and once again was amazed with how well the antenna would null offending signals. The best way to mount the antenna is in a system that allows for Azimuth and elevation placement for optimum performance.
KE6EE Rating: 5/5 Mar 1, 2013 15:13 Send this review to a friend
Works damn well  Time owned: 0 to 3 months
I use this as an alternative RX antenna on 80 and 40 meters where powerline and other noise in my urban environment produces a noise floor of about S6. I stuck the antenna on a tree branch about 7 ft. above ground, well below my transmitting antennas which sit on my roof or 15 ft. above the roof. Noise is down to about S1 and CW signals which were difficult to copy in the noise become clear and easy to hear. I wound the ferrite with 13 turns of wire and the frequency range appears to be about 3.4 mHz up to about 11 mHz which is just what I need.
K0RWM Rating: 5/5 Feb 6, 2013 20:01 Send this review to a friend
I love it, it works!  Time owned: more than 12 months
I built one of these about 5 years ago and it works great. I was going to build an external loop using a varactor diode tuned shield loop through the feedline. That is what the SM-100 is and for about what I would have spent buying the parts, instead I have a neat looking and well working unit. It has a FET amp which keeps the loop Q high. I am going to change from 70 turns on the large diameter 7.5 inch ferrite loop which tunes 490 kHz to 1.67 mHz to cover 160 and 75 meters. For example 32 Turns tunes 1.2 mhz to 4.11 mHz. The null if very sharp. I can see setting it out in the yard and nulling out the neighbors plasma TV. 20 Turns tunes 1.9 mHz to 6.5 and 10 turns tunes 3.8 to 13 mHz. Get the shielded loop outside, away from household electrical noises and tune the to the exact frequency from turning a pot I do not understand why more people are not talking about and using this antenna. I just helped an experience SWL friend assemble one the last several nights. He is blown away. It is not a toy.

W0FEN Rating: 5/5 Dec 12, 2011 07:59 Send this review to a friend
Great Faraday Antenna  Time owned: more than 12 months
I put this kit together over year ago. I use it to receive an AM Broadcast Station. It is in a noisy computer environment and does exactly what it is designed to do. Since it can be wired for up to 20M it will let you work when there is lots of electrical noise. Take time when assembling. This will produce a good result. Remember a Faraday shield cannot be a shorted turn. There must be a gap. For the price it can't be beat. I have not used it for Ham/SW reception and so cannot rate it for that.

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