Tecsun AN-48X Loop Antenna: One simple suggestion to improve performance

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!

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5 thoughts on “Tecsun AN-48X Loop Antenna: One simple suggestion to improve performance

  1. Robert Richmond

    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.

    Reply
  2. RonF

    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?

    Reply
    1. Robert Richmon

      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.

      Reply
  3. Tim Trammell

    Any Idea where to get something like this? I’m disappointed in my AN-48X, and this might be worth a try.

    Reply
    1. Robert Richmond

      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. 😉

      Reply

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