A "QRP" loop antenna from AliExpress, unboxing, first look, assembly and tests
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- Опубліковано 12 лип 2024
- I purchased a curious "QRP" loop antenna from AliExpress (I say QRP in quotes because the item is rated at 20 watts max and QRP is 5 watts), then assemble it, test it out, and then open up the control box and balun and find out what is inside these.
The loop part itself appears to be a piece of almost rigid extremely low loss coaxial cable, which holds itself in a loop shape when connected to the matching control box which uses two capacitors and a switch to increase and decrease capacitance, and how this works is revealed when I open up the matching unit.
I tried it on WSPR a couple of times, the second attempt the loop was near my living room window and the results were better, however it is useless inside the flat because of the electronic noise being generated inside the building, some of which may not be originating from my flat.
For the CB guys this doesn't work there without modification to change the capacitance and possibly a different size loop.
I have so far managed to get it to tune on 40 and 20 metres, though if I want to properly use it I will need to get out and buy a leisure battery to run the FT991A out in the wilds away from electrical noise
#amateurradio #hamradio #antenna #antennas
Chapters:
0:00 introduction and unboxing
6:57 Assembly
9:47 Tripod mounting
12:15 Checking resonance and tuning
17:29 Connected to the FT-991A and transmitting WSPR (1st attempt)
33:20 Inside the tuning box and balun box
41:40 Loop positioned near opened window and second attempts with WSPR
46:05 Conclusion - Наука та технологія
Nice one Paul, I was thinking of getting one of these antennas myself as they can be quite surprising. Keep up the good work 👍👍
I used the MFJ 9232 QRP loop tuner and have had great success with it, I made up some loops with 10mm soft copper pipe and it works surprisingly well, especially the loop for 10m, it's tiny....
I also have the MFJ-9535c 150 watt loop tuner and use the same loops I made up for the QRP tuner, the extra power makes all the difference, I can sit the tuner on a table and with the FT-891 on 50w or 100w I never fail to make contacts and don't have to mess with radials.
For anyone with limited room for antennas the MFJ-9525c is excellent and can handle up to 150 watts but I've only tested it at 100w SSB. I've taken it portable also.
I use the QRP loop tuner a lot with the FT-818 sat on a tripod with a mobile phone to tripod clamp, it won't take big loops but small ones will work fine and remarkably compact when 10m is open, would probably work well on 11m also.
what is the problem with rg-174 for hf use as long u not putting full power and only 5 w then u fine
I just got mine today and noticed that it wouldn't tune above 12m I opened up the box and adjusted the top poly cap and got it to tune to 30mhz. I turned the adjuster that has the wire from the top terminal of the switch to the terminal on the poly cap. It didn't take much and now I get a good match on 10m
The "matching box" is a common mode choke.
How can you work in that heap of stuff??
A link would have been nice so we can check it out !
Почему эта антенна у меня не работает на передачу?
*Эта антенна не хочет работать на передачу! Нахожусь в многоквартирном доме. 10-й этаж. Антенна стоит на балконе.*
you sound like Eric Idle
Wow..those antennas are $100usd to $160usd..plus shipping..yet are made from about $10usd worth of parts..what a RIP off..
I love how people talk about things from AliExpress. Everything seems so hard to use, and so confusing. They are never quite sure how it will work. But if they would have bought same exact thing from a store in their country it would be wonderful and so easy to use and assemble. If they want to pay 5 times as much for an item because it came to them from inside their country and it makes them feel better or prouder...be my guest.
Lol I completely agree. In this case I couldn't justify spending a ton of money on a loop from dx engineering so I bought this. If some fiddling and tuning is needed I definitely expect that. In my earlier comment I explained what I did to get mine to resonate on 10m and will be testing it more in the future.