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Author Topic: The Best Active Loop Antenna 2019 = MLA-30?  (Read 2038 times)

Offline alpard

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Re: The Best Active Loop Antenna 2019 = MLA-30?
« Reply #45 on: July 20, 2020, 0602 UTC »
Good point. 

Here is MLA-30 comparison with other Loops by the youtuber.
https://www.youtube.com/watch?v=V7bp5OII0rs
« Last Edit: July 20, 2020, 0631 UTC by alpard »

Offline alpard

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Re: The Best Active Loop Antenna 2019 = MLA-30?
« Reply #46 on: July 23, 2020, 0924 UTC »
My MLA-30 plus arrived yesterday.  I temporarily set it up in the room for testing, and it works very well.
I found that,

1. it is very directional. For receiving Radio Japan on 15Mhz, it completely nulled the signal out when positioned East West.
When turned to North South, the signal peaked and copied.

2. Supplied wire element is good for up to about 7 Mhz and above. Below that it degrades performance.  Then when attached with long wire with alligator clip on the element for 6Mhz and below, the reception works better.

I think it is better than anything I have had - long wire and active whip.  I think this is a great DX antenna, but will need to set up on a little tripod, and should be rotated.

It could be set up as horizontal for omni directional antenna, but most BC stations on HF seem transmitting on vertically polarised antenna. But one could do some testing on that to figure out which polarisation works better.
« Last Edit: July 23, 2020, 0927 UTC by alpard »

Offline redhat

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Re: The Best Active Loop Antenna 2019 = MLA-30?
« Reply #47 on: July 27, 2020, 0725 UTC »

...It could be set up as horizontal for omni directional antenna, but most BC stations on HF seem transmitting on vertically polarised antenna. But one could do some testing on that to figure out which polarisation works better.

FWIW every curtain antenna I've every seen at a shortwave broadcast station was horizontally polarized.

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Offline alpard

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Re: The Best Active Loop Antenna 2019 = MLA-30?
« Reply #48 on: July 27, 2020, 1059 UTC »
Then horizontally installing the rx antennas are OK? You don't need to get the rotator.
Rotator sounds a bit too much hassle due to the amount of cables wired into the control box, and also they tend to be expensive.

Offline RobRich

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Re: The Best Active Loop Antenna 2019 = MLA-30?
« Reply #49 on: July 28, 2020, 2235 UTC »
As Chris noted, it is an inexpensive video amp IC with a bias tee power feed.

There is no particular reason it even has to be used for a loop as shipped. It could be used as a remote preamp for a variety of antennas, though I would suggest sticking with something balanced like a dipole, T2FD, loop-on-ground, or similar. It might suffice for a reduced-length beverage as well, though I suspect it might actually lower the actual resulting SNR of a quiet antenna given the amp design. YMMV.

I have a MLA-30 of whatever revision, though I have not done much with listening with it. It worked "okay" in a quick test with an indoor scrap wire loop near an exterior sliding-glass door.

Of note I removed the USB port and bypassed the regulator to feed DC without the voltage conversion. I have not done any testing at difference voltages, but a 9v battery seems to work okay. Lower voltage into the amp might even improve the noise, phase distortion, etc. Again, YMMV.

@alpard, if opting for a horizontal solution, either get it high as possible with a small loop like the one packaged with it to help limit ground losses, or alternatively consider trying it with a loop-on-ground of moderate size.
« Last Edit: July 31, 2020, 1712 UTC by RobRich »
Tampa, FL USA | US Map Grid EL88
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Offline alpard

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Re: The Best Active Loop Antenna 2019 = MLA-30?
« Reply #50 on: July 29, 2020, 0732 UTC »
Thanks for your info and advice.

My 2nd MLA-30 arrived this morning.  It was in a small bubble plastic packet, and very light. I couldn't believe it was the MLA-30.
Upon opening the packet, I noticed it was MLA-30+ instead of MLA-30 I ordered.

So, I have 2x MLA-30+ now.  I have been using the 1st MLA-30+ for about a week now, and it works great.  It pulled many DX sig. I have never heard before, or struggled copying with my long wire such as CFRX Toronto 1KW on 6070 and Zambia NBC1 from Lusaka Zambia, and TWR from Botswana ... etc etc.  It seems work better at nights.

There are times and signals that LW works better, so it is good to have both antennas.

Yes, I think it could be used as general RX ant. rather than just magnetic loop.  It worked quite well when connected to a random length of wire too.

The 2nd MLA-30+ will be used with larger and thicker element to cover the lower freq. better.
« Last Edit: August 01, 2020, 0938 UTC by alpard »

Offline RobRich

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Re: The Best Active Loop Antenna 2019 = MLA-30?
« Reply #51 on: July 31, 2020, 1722 UTC »
The discussion inspired me to continue modifying the MLA-30. I removed the attached coax and installed a connector at the preamp. Now I can use RG-6 or whatever.

Linked below are a couple of pics showing the MLA-30 as a preamp for a YouLoop simply hanging on a kitchen chair near a sliding glass door. Worked about as expected for an indoor antenna here.

https://imgur.com/a/fGCz3Yk

Now to get the MLA-30 outside sometime. Maybe over the weekend.
« Last Edit: July 31, 2020, 2047 UTC by RobRich »
Tampa, FL USA | US Map Grid EL88
Kenwood R-600 + R-2000 | Airspy HF+ Discovery | 2x RTL-SDR V3 | Si-Tex 200 | Soft66LC4 | Yaesu FRG-7
Ameco PCL-P | MFJ-784B | MFJ-901B | 2x MFJ-1020B | MFJ-16010 | 2x Timewave DSP-9
148' "Shielded" Loop-on-Ground | 18' End-Fed Vertical | 9' + 31' Verticals

Offline alpard

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Re: The Best Active Loop Antenna 2019 = MLA-30?
« Reply #52 on: August 03, 2020, 0611 UTC »
Looks interesting. Let us know how it worked.