Hi all
I just received today from Amazon a Sutekus loop antenna, thinking it appeared the same as the Tecsun AN-200. To my surprise it was both! See the below pics for explanation. In terms of effectiveness I am hugely disappointed. I was under the impression that it would enhance weak stations, but that wasn’t my experience. The first radio I tried it on was my Tecsun PL-330. I tried multiple positions all round the set, tuning the full sweep of the unit (not very great) in each position. The only effect I noticed was, in what I assume was the tuned position, was loud static. Next I tried a Philips AE-3405/01 with exactly the same result. I then tried a very cheap and nasty NT-999 which produced a minor level of enhancement and showing a surprisingly wide tuning range which separated on one occasion three stations within it’s sweep. So, I don’t feel I can send it back, because it does actually work although I’ll probably never use it again. If anyone else has a more positive experience with this I’d be interested to hear it. My own recommendation is to avoid it. 

Drifter

Op 28/01/2022 om 19:55 schreef FenDrifter via groups.io:

Hi all
I just received today from Amazon a Sutekus loop antenna,

I have a "true" tecsun.

- It tunes very fine, so don't turn the wheel too fast.
- connect it to a standard tuner ...


Marc
--
The "Penguin" has arrived - and he's not going away - ever.
For former Apple users: Xubuntu.org (menu's up left)
For former Windows users: Lubuntu.org (menu's down left)

Hi Marc
What do you mean by a standard tuner please?
Drifter
p.s. Glad to see you’re a Penguin man, I’m a Ubuntu man myself, running on my Dell laptop. But I’m writing this on my iPad 🤭

Yours is not an uncommon experience but it would help to understand some things about how these tuned passive loops work, and this will hep to explain why they seem not to work in some circumstances.

Except in the extremely unlikely event there is a broken connection in your loop, again, highly unlikely, they will indeed provide give a noticeable gain in signal strength, several db. So why does it seem it is not working for you?

The most common reason is that signal strength is not the limiting factor in your reception, but rather, signal to noise ratio. This is significant because in the later case the antenna will amplify the noise along with the signal, so the net result is no observable change. In the old days when radios had analog signal meters it was easier to see the signal meter jump when the antenna was peaked but with many radios with no meters or less obvious metering the gain may go unnoticed. But it is still there.

One other thing that happens with some DSP tuned radios like the PL-330 is that the DSP chip tunes the radios input to the ferrite rod and introducing an external antenna inductively may upset this tuning. I have experimented with my AN-200 and PL-330 and it is indeed trickier to see the improvement but it is there. You might try aiming the radio improperly to minimize the signal strength to peak the AN-200 more precisely, then re-orient the radio and you should see a higher signal level on the meter. Also try varying the distance between the radio and the antenna as you peak the antennas tuning ...you should hear a blip as you cross the proper tuning spot.

Jay

Hi again Jay
Very many thanks for your input on this, it’s definitely appreciated. Not only your take, but additional info I wasn’t aware of. I do wonder if mine is damaged, as there appear to be two breaks (?) on opposite sides of the loop inside. I’m going to attach a couple of pics, and would very much like to know if they’re all like this or whether it is actually damaged. 

Thanks again 
Drifter

I have similar experience to Jay Allen with the AN200. I wasn't impressed when I used it with a Tecsun DSP radio.
As Jay said there is an improvement but not spectacular. On the other hand, using an AN200 loop with an analogue portable or a PLL portable gave good results. It can certainly null noise and boost a weak signal. I had some good results with analogue pocket radios with the AN200. Unfortunately my AN200 and most of my portable radios are in the UK and I'm in Botswana so I can't make a comparison video. I have several videos on my YouTube channel showing use of the AN200 but I can't remember the titles. I'll try and find some. I have hundreds of videos!

Peter Wilson

Here's a video with an impressive signal boost using a Tecsun AN200!
https://youtu.be/NHSuJ9zcvJ8
Peter

Hi Peter
Yes, that is impressive. I found this one: https://youtu.be/1VZAkDVPj_w
which shows a direct connection into a PL-330 having disconnected the internal ferrite rod. I tried this and was definitely able to tune a better signal, so maybe the two photos I posted earlier don’t show damage? I have to admit that I’d be a lot more confident about the whole affair if those ‘broken’ areas weren’t there! I’m toying withe idea of requesting a replacement. 

Drifter

Thanks for that Kevin, all grist to the mill! I particularly liked the screwdriver idea, simple but easy, great!
Drifter

Hello
Here is my channel with tests of the AN200
Hope it helps ☺️☺️☺️
https://m.youtube.com/playlist?list=PL12803A0C1E2082A4

You could better turn the antenna to the maximum possibly signal by first finding the zero point in your radio Then turn by 90degs and doing the same on the loop

Hi Zacharias
Many thanks for info and links. I had a good look at the close-up shots of your antenna, and I could not see any marks similar to the ones in my two photos above, do you think mine is damaged please?
Drifter

I just looked at mine under a bright light and don 't see anything like these lines so it is possible it is broken...this is the first time I've seen anything like this. Two ways to check would be to try it with another radio...preferably an analog radio which is less tricky to use with a loop so see if it works at all. Otherwise you would have to disassemble it and check for continuity. Did you say you got two of these with your order? Can you get a replacement?

This is strange to be sure.

Jay

Yes. The less sensitive the radio the more dramatic the improvement and this Panasonic is not vey sensitive on AM. Good video.

Jay

Hi Jay
Many thanks for taking the time to look at yours, it’s appreciated! No, I didn’t get two, and I now don’t have one, it’s been returned to Amazon 🙂. My decision now is whether or not to get a replacement 🤔. I think I will, purely to satisfy my curiosity. 

Once again many thanks 
Drifter

Drifter

Ah! I sent mine back! Oh well, many thanks for that anyway David, more knowledge to digest 😊.

Okay all!
I bought another one! This time it was called Hwydo AN200, but they’re all the same. This time I’ve learned some very valuable beginners lessons. If you’re reading this having never used one of these before, don’t expect miracles! Secondly, the point of tuning enhancement is very small, you only have to virtually touch the knob to get it right, that is one you’ve found the maximum noise point it will be to one side of that. I found all this out this morning when I had the bright idea of trying it with my Panasonic RF-2200. This has needle type signal strength meter which was key to all! Having found a usable station (none were very good this morning, appalling conditions) I tuned the rotating ferrite antenna to optimum position, and then having positioned the antenna closely at ninety degrees to one of it’s ends, I went ahead and tuned it. I should say that the needle position was approximately mid point, so any deflection would be quickly obvious. Doing this made it clear that the maximum gain point was very small, much smaller than I had imagined it would be. If I’d known how very small this gain point was, I wouldn’t have been so quick to return the other one. I sa an interesting video on YouTube where somebody compared the small ferrite antenna supplied with the (I think) PL-368 with an AN-200 and there was no difference, this surprised both him and me, but of course the loop isn’t restricted to one or two radios. I hope this might be of help to someone. 

Drifter