Magnetic Coupler - Can you still get them anywhere?

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Omega-TI

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I'm starting to get back into radio after about 20 years and dug out my old Palomar Loop Antenna, but the "Ultralight" radio I want to use it with, a Retekess V115 has no AM antenna input. So I'm wondering, does anyone still sell a magnetic coupler for a radios internal antenna? (Like the one shown in the attached PDF)?

Loop Antenna.jpg
 

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  • Palomar Engineers LC-1 Loop Coupler Manual.pdf
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majoco

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As long as your radio has an internal ferrite antenna then you already have a magnetic coupler! Just bring the two close together and experiment a bit with the the position of the radio against the loop for the best signal. Another approach is to buy a piece of ferrite rod or salvage one from somewhere - if you salvage one from a busted radio with coils on it, even better. Wind a few turns of insulated wire around the rod and connect the two ends of the wire to the output socket on the amplifier. Again experiment with the placement of the rods and the radio for best signal transfer.
 

Boombox

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I don't know anything about the Palomar loop in the pic, but you could try wrapping the extension antenna wire (going out from the Palomar) around your portable radio and see if that works. Your internal loopstick in the portable radio might couple to the Palomar that way.
 

Omega-TI

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As long as your radio has an internal ferrite antenna then you already have a magnetic coupler! Just bring the two close together and experiment a bit with the the position of the radio against the loop for the best signal. Another approach is to buy a piece of ferrite rod or salvage one from somewhere - if you salvage one from a busted radio with coils on it, even better. Wind a few turns of insulated wire around the rod and connect the two ends of the wire to the output socket on the amplifier. Again experiment with the placement of the rods and the radio for best signal transfer.

Yeah, that would work, but honestly I was preferring something with a 'clean appearance' and little less of a time investment. While I know and understand the principles behind it and could probably buy the parts to make one off of Ebay, it may not be as efficient and for sure not a pretty or sturdy. In the end, I may be forced to go down that path, but my den is enough of a mess right now, I just don't have the heart to mess it up even more.

From what I've been able to determine, interest in radio has tanked since I left the hobby about 20 years ago. I'm glad you guys are here, because otherwise it would seem like a giant wasteland.
 

ka3jjz

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I had the battery powered version of that antenna for awhile. It really isn't meant for portables in the first place - the one I had was set up with a SO-239 in the back for a coax connection. This antenna (at that time) was meant for desktops (and some ham transceivers - general coverage radios in a ham radio wasn't common back then).

Inductive coupling (which is really what we're talking about here) is still possible with other designs, though and there are some commercial units for AM BCB floating around. Like these, for example;




If you're into MW DXing, then check out this page for a lot more...there are several clubs and such into the same


Mike
 

ka3jjz

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I know you said you didn't want to make more of a mess in your den, but this might be for others with a bent for homebrewing....


And there are bigger versions of the FSL out there, too....Mike
 

Omega-TI

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I had the battery powered version of that antenna for awhile. It really isn't meant for portables in the first place - the one I had was set up with a SO-239 in the back for a coax connection. This antenna (at that time) was meant for desktops (and some ham transceivers - general coverage radios in a ham radio wasn't common back then).

Inductive coupling (which is really what we're talking about here) is still possible with other designs, though and there are some commercial units for AM BCB floating around. Like these, for example;

Yep, it has an SO-239 on the back. It was hooked up to the Pioneer VSX 9700 in the living room BITD, basically for one station as the nulling effect and the amplification was needed. For a decent tuner, the OEM loop AM antenna really sucked. Currently I'm not willing to invest in a portable that has its own external antenna jack because I'm waiting on a RTL-SDR to play with.

Thanks for those links, I'll check them out!
 

Omega-TI

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I found a new goodie online today! (y)

Goodie.jpg

I'm thinking the heck with the coupler for the V115, I'll just use this for the Palomar Loop and the RTL-SDR, but like everything else in radio... you ALWAYS need something more. Now I have to hunt for an antenna switch...
 

ka3jjz

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Watch your gain - trying to put the Palomar on a small ultralight is going to be WAY too much signal for it. That version in the first post didn't seem to have what the battery powered one I had - a gain control. You may have to off tune it a bit to avoid overloading it. No sweat with a good desktop or ham transceiver in most cases, but portables- not so much

Mike
 
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