Hi there, as most of you know, my QTH suffers very badly from local QRM - and of course I know a lot of you of also have the same problem. This has resulted in my not being able to conduct any MW DX in the early evenings; in fact I'm not able to operate with even a reasonable noise floor until well after midnight when the neighbours have switched of TVs etc. and gone to bed. Thus, I'm usually up half the night when I want to DX on Medium Wave and similarly with Shortwave. Thank goodness for the recording facility on the Elad FDM software. If it weren't for that, I'd have gotten even less sleep these past two years!
Dennis at Bonito sent me one of their Galvanic Isolators for testing. They work by isolating the path of the direct current between the outer shield of the coax cable and the shielding of the antenna feed line. In doing so, a toroidal transfomer can suppress interference caused by the potential difference between these conductors. In addition, the inner conductor of the coax cable is electrically insulated with capacitors and integrated with and coarse and fine voltage surge protection. Sounds good to me and at a cost of only 59 Euros, if the GI300 works, it's money very well spent indeed.
The GI300 covers a wide-band range of 30 kHz - 300 MHz (typically with around 1dB insertion loss). The unit can be used with almost any receiver capable of connecting to an external antenna and will also work at frequencies up to 1 GHz. However, above 300 MHz, the insertion loss may increase by up to 3dB.
One word of warning; The connection between the GI300 and your receiver input should be as short as possible. I tried mine on the antenna side of my antenna switch and it still worked very well, but best results are obtained if you connect it directly into the antenna socket of your receiver. I used a PL259 to BNC adaptor for my Elad FDM DUO and the GI300 plugged straight in. Note also that whilst it is impossible for the GI300 to pick up electrical interference (this is intrinsic to the toroidal transformer and strip line design) it could still occur if you have a length of effectively potential-free transmission line from it, to your receiver.
Here is the first of my test videos.
THE FIRST 60 SECONDS ARE WITH THE GI300 IN CIRCUIT AND THEN WITHOUT.
As you can see, the GI300 makes a huge difference to the noise floor on the Elad FDM DUO, coupled to my Wellbrook ALA1530 magnetic loop antenna (outdoors). More videos to come.
Thanks for watching.
Dennis at Bonito sent me one of their Galvanic Isolators for testing. They work by isolating the path of the direct current between the outer shield of the coax cable and the shielding of the antenna feed line. In doing so, a toroidal transfomer can suppress interference caused by the potential difference between these conductors. In addition, the inner conductor of the coax cable is electrically insulated with capacitors and integrated with and coarse and fine voltage surge protection. Sounds good to me and at a cost of only 59 Euros, if the GI300 works, it's money very well spent indeed.
The GI300 covers a wide-band range of 30 kHz - 300 MHz (typically with around 1dB insertion loss). The unit can be used with almost any receiver capable of connecting to an external antenna and will also work at frequencies up to 1 GHz. However, above 300 MHz, the insertion loss may increase by up to 3dB.
One word of warning; The connection between the GI300 and your receiver input should be as short as possible. I tried mine on the antenna side of my antenna switch and it still worked very well, but best results are obtained if you connect it directly into the antenna socket of your receiver. I used a PL259 to BNC adaptor for my Elad FDM DUO and the GI300 plugged straight in. Note also that whilst it is impossible for the GI300 to pick up electrical interference (this is intrinsic to the toroidal transformer and strip line design) it could still occur if you have a length of effectively potential-free transmission line from it, to your receiver.
Here is the first of my test videos.
THE FIRST 60 SECONDS ARE WITH THE GI300 IN CIRCUIT AND THEN WITHOUT.
As you can see, the GI300 makes a huge difference to the noise floor on the Elad FDM DUO, coupled to my Wellbrook ALA1530 magnetic loop antenna (outdoors). More videos to come.
Thanks for watching.
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