indoor loop antenna recommendations...

[East Troy Don]

Happy New Year everyone!   I am in the market for an indoor Loop to use with my  recently acquired Tecsun 990X and my soon to be delivered (hopefully) Malachite  SDR.  It doesn't matter if the Loop is Active or Passive.  High Sensitivity is slightly more important than Low Noise as I live in the heart of Wisconsin farmland . As always, I find that fellow HFU'ers provide  the best answers to topics such as these so any recommendations will be greatly appreciated.
Thanks and hoping for a prosperous and healthy 2022 to all,
Don

[Erik Mattson]

I've not used one, but the MLA-30 seems popular. And theres a MLA-30+ version, too. Like 40 bucks or so. Might check one out myself before too long.

[East Troy Don]

Thanks .  The MLA -30 has gotten some pretty respectable reviews but it appears rather large  for indoor application.

[Erik Mattson]

Now you got me thinking. There was an indoor active loop "THAT WORKS!" on the Tech Minds channel on YouTube, but I must've forgot to save it to a play list. Give that channel a look.

[East Troy Don]

Will do. Thx

[~SIGINT~]

I purchased a YouLoop well over a year ago and I am very pleased with it. I tie a small piece of rope between the top and bottom connector points in order to keep the form and then just hang it in a window. If you want it steerable then you will need to manufacture some kind of frame for it. Beware of counterfeits (and there are lots of them out there) and purchase it from Airspy.

There is a nice MLA vs. YouLoop shootout here:
https://www.youtube.com/watch?v=gyI33hs590o

[Elf36]

Not familiar with the Youloop, but I've seen good things about it. I also have an MLA-30 loop and it's not nearly as terrible as it's made out to be. It works just fine for standard shortwave listening. For Utility, Pirate and beacon listening, a dipole outside provides better RX capabilities, but all in all, it is a decent antenna for the cost. I have a Grundig G3 in my office and I think I might install it there. I tend to use my 135' OCF dipole and HF rig for day-to-day listening.

[~SIGINT~]

The MLA-30 was once on my "shopping list" to try but I then opted for the YouLoop for its portability. It travels well with my Belka DX and requires no power. The YouLoop also routinely come on sale at almost 1/2 off the regular price and depending on which Airspy distributor you use, also includes free shipping. My main loop antenna is a Wellbrook installed on a rotator.

[kris]

  I wrote about my rebuilt MLA-30 at the beginning of its appearance on the HFU.
Let me just repeat that it is worth experimenting with its reconstruction
 - the amplifier is connected to the coupling loop, and the large basic loop is tuned to resonance.
 Find the best location!
There is information on the net that the MLA-30 + has a better (less noisy) balanced amplifier and an improved power supply (without a DC / DC converter).
 These antennas are worth the money spent!

[RobRich]

I bypassed the DC converter in the MLA-30 as well. I have yet to ever actually deploy it, but it worked fine at 9v to 12v direct in my very limited testing.

I also installed a connector at the loop preamp so use whatever type and length of coax. Usually cheap RG-6.


I have been keeping a YouLoop in a window as a backup MW/HF antenna for when disconnecting outside antennas like during storms.

It works okay for casual listening in that role, though there are a couple of technical caveats. Impedance can vary widely by frequency, and naturally given the size, gain is well into negative numbers. You might need to deal with one or both aspects. I have posted a NanoVNA sweep of the YouLoop, plus my experience using a L-match tuner to improve the match with a Grundig G3 portable.

https://www.hfunderground.com/board/index.php/topic,71326.msg241978.html

Alternatively a preamp can be used instead of a tuner. I have used the YouLoop with an old MFJ MFJ-1020B, though have found even a basic preamp like the Nooelec LaNA can work, though some attenuation might be needed depending upon local noise floor, signal overload, etc. YMMV, of course.

[East Troy Don]

Splendid info, guys.   I just received my Malahit DSP SDR V3 this morning. Since the ChiComms insist on sending this radio with no manual I have spent a few hours "trial and error'ing" my way thru the myriad of menus and submenus. So far so good. I think once I get a decent antenna hooked up this radio will perform as advertised. Needless to say,  the flimsy "rubber ducky" antenna is pretty useless but I guess thats life in the big Shanghai.
Thanks again.

[~SIGINT~]

Try these links for an English translation of the Malachite DSP receiver manual and additional information.

http://linuxslate.com/Instructions_Malakhit-DSP_en.pdf
http://linuxslate.com/Instructions_Malakhit-DSP_en_2.pdf

Malachite DSP - SDR  Radio Receiver
http://linuxslate.com/cgi-bin/forum/YaBB.pl?num=1595619341

[ultravista]

~SIGINT~ how does it compare to the Wellbrook? I have a Pixel 1B and thinking about getting a Wellbrook as a second antenna.

[East Troy Don]

Sigint, thanks for the links.

UltraV,  from what i've read and seen on YOUTUBE the W6LVP loop performs almost identically to the Wellbrook at less than half the cost.

[~SIGINT~]

Both the Wellbrook and the W6LVP are no match against the YouLoop or MLA-30. My Wellbrook outperforms my YouLoop and my home brewed loop antenna. It is not so much so the physical antenna portion itself which is important but the quality of the pre-amp that is the more critical part. The passive loop that I built was nothing more than a left over piece of heliax that I had laying around and a matching transformer which I spun myself on a toroid. That antenna actually worked pretty well and was my test antenna to determine if I wanted to invest the money into a Wellbrook or similar product. I still have the home brew and considered perhaps either adding a Nooelec pre-amp to it or modifying it into a transmitting loop.

There are no shortages of comparisons and videos between the Wellbrook, the W6LVP, the Pixel and most recently the Chameleon. Keep in mind though that most of these are really outdoor antennae. Wellbrook used to manufacture a smaller indoor model of the 1530. I am not sure what is currently available but their new FLX1530LN looks interesting.

I would suspect that your Pixel is most likely a decent loop. I have no experience with that one.

For anyone looking to get into loop antennae, I would recommend that you first spin your own using coax, use a good matching transformer and pre-amp (optional) from Nooelec. If you like the results you can then determine if you want to invest in a commercial product. There is nothing complicated in building a receiving loop and for test purposes, the parts are cheap.