Many thanks to SWLing Post contributor, Robert Richmond, who writes:
I recently received the new Tecsun AN-48X loop antenna. I have not had much time to thoroughly test it, but I can make one immediate recommendation IMO. Replace the bundled “feedline” between the loop and controller with an actual *shielded* 1/8″ male-to-male stereo audio cable.
The bundled cable causes near-hand capacitance at the controller, potential RFI issues, etc.; at least for my received unit. The noted concerns largely corrected when replacing the bundled cable with a 6′ shielded audio cable. Tuning now works as expected, and SNR seems much improved.
I have longer 12′ shielded cables and some 1/8″ female-to-female couplers on order to eventually try longer feedlines should the need arise. I will try to drop you a line if/when I get around to testing them.
That’s a sound suggestion, Robert! Thanks for sharing!
I bought a Tecsun PL-310ET and this antenna kit in the last week and after finding this post I ordered the cable you went with for the “feedline” from the Amazon link you posted. Now it’s still a few weeks away from delivery since I only ordered it yesterday but I’m hopeful I can get decent results with the triple shielding.
And I wish I knew what was going through Tecsun’s mind when the makers went with the length of cable for the “feedline”. It’s so ridiculous and I’m sure I’m not the only person who feels this way.
Anyway I know this post was originally made in 2020 so I hope you still recommend this cable to anyone looking to change what Tecsun gave us in this kit.
Received my “DuKabel Top Series” shielded audio cables. A quick test with the DuKabel 26′ cable works as well as the generic-branded 6′ shielded audio cable I tested earlier.
https://www.amazon.com/dp/B07PHSR9T2
I ordered enough DuKabel cables to run up to 50′ of feedline via female-to-female couplers if needed. Remains to be tested. I not expecting any issues with the extra length, though, as the antenna controller has lots of gain range available.
I haven’t seen one in the flesh yet, and most of the pics / reviews online aren’t enlightening – but, by “the bundled “feedline” between the loop and controller”, are you indicating that the wire between the loop & control box is not coax but a figure-8 or twin-lead flat cable?
If so, I wonder if it’s not a deliberate choice – either to minimise loop/feed capacitance (which will affect tuning range &/or Q; coax is typically ~double that of flat cables), or minimise common-mode noise pickup in the feedline & loop (especially relevant for antennas like this, mostly used indoors or near noise sources including the receiver itself) which is a real PITA to deal with?
Yes, the “feedline” between the loop and controller. It is just a basic 1.8″/3.5mm male-to-male stereo audio cable. Pretty much just like the previous Tecsun portable loop used, too.
The provided cable is extremely thin with ultra high-gauge wires and quite likely no mylar shielding.
Any Idea where to get something like this? I’m disappointed in my AN-48X, and this might be worth a try.
It is not an explicit recommendation, since I have not used the brand, but here is a well-rated example at Amazon:
https://www.amazon.com/DuKabel-Audio-Cable-Feet-Meters/dp/B07KQ62WSV/
Of which I likely will be ordering to try, too, as the eBay vendor I used sent the wrong cables. Not worth the hassle of returning them, so I probably will buy one or two lengths of the above linked cables this time.
Whatever the brand, a shielded cable is worth a try IMO. My AN-48X was working rather poorly until I changed the cable. Tuning problems, stray capacitance, RFI, and similar. Changed to a shielded cable, and most of the issues disappeared. It went from largely just noise to actually being able to tune into a few 40M-band QSOs with the antenna in an admittedly rather poor signal spot inside the house during my initial testing upon receipt of delivery.
I need to get around to trying the antenna outside in the yard. 😉