Modern ham radio operators often face restrictions on antennas. This has made small antennas more popular, despite some limitations. [Tech Minds] reviews the GA-450 indoor active HF loop antenna and finds it better than expected. You can see the video review below.
You can’t expect a little antenna to perform as well as giant skyhook. However, for such a small loop covering 3 to 30 MHz, the antenna seems to perform very well. We like that the active part of it has a rechargeable battery. Obviously, you will only want to use this antenna for receiving, but it would be a great pairing for an HF-capable software defined radio (SDR). Even just in the window sill with half gain, it was able to pick up quite a bit of signal on the 40 meter and 20 meter ham bands. According to the video, performance below 7 MHz was lackluster, but it worked nicely at higher frequencies.
The loop is directional and you can rotate the loop on the base to zero in on a particular signal. Of course, if the antenna were up in the air, it might be harder to rotate unless you work out something with a motor. If all you want to do is receive and you have a budget of under $100, this looks like it would be a nice portable option.
You can build your own loop and loop-like antennas, of course. Some of them can be quite portable.
It is obvious there is no way to tune that antenna: the only adjustment is for preamp gain.
Now, it is receive only, and you don’t *need* high antenna efficiency for receive at HF (since environmental noise dominates over preamp noise for all but the poorest antennas), so they can get away with a deliberately limited design.
I suppose it ticks the boxes in the product requirements, so it doesn’t *need* to be resonant and tunable, and most listeners would prefer the dumbed-down interface anyway.
Not true, what the knob does is tuner a varactor diode but only about 4 Mhz – 16 Mhz is tunable. The gain is pretty much fixed at 20 db
But where’s the hack? Where is the description of how it operates? Teardown? Technical discussion? It’s not even a quantitative review. Just a glowing description of how the reviewer feels it’s surprisingly great.
It’s just flogging a product, with a nice helpful link for how-to-buy-it and affiliate links to other products.
Time to be more selective in your articles please, HaD.
Couldn’t agree more. This kind of
‘review’ isn’t what I read hack day for
He opens it up at the end of the video.
It’s not a hack. A hack would be if someone made such an antenna for fraction of the cost and compared it to this one. I have a book from 1980’s titled “Radio-amateur’s Handbook” that covers building such antennas and other equipment. It was written when my country was communist republic and semiconductors were expensive and hard to buy. These were grim times, almost as bad as current semiconductor shortage. ;)
The video doesn’t show much of anything useful. It doesn’t show a useful comparison to anything else (like even a simple whip antenna) in the same location, and it doesn’t even show a dB comparison to the end fed antenna. Where is the actual science in any of this?
This is a head scratcher. I’m not sure how it turned up on Hackaday.
Reminds me of those TV antennas that you see advertised with “_____ mile range!” I’ve seen them with 600 miles.
Of course you could claim 240,000 miles range from the moon, but only 12 hours a day. And you’d need a bit of gain in your receiver.
After waiting over a month and a half I finally received the antenna from banggood. I paid $88.45 including shipping. I had a chance to test it out and I was NOT very impressed with its performance. Also, the battery does not last that long before charging it again. I tested it with a Sony ICF-7600D receiver, an ICOM R70 communications receiver, an RTL-SDR.Com dongle, a SDRPLay RSP1 and a Airspy + Discovery SDR’s. With the Sony unit the signal improvement was next to nil. With the SDR’s it hardly picked up a signal at all compared with other antennas I usually use. After seeing the video from TechMinds I was very hopeful that this antenna would perform better than antennas I have been using. I do not know their testing procedure, but I did not get what they presented. Do not waste your money on this antenna. My YouLoop passive magnetic antenna, my Archer reel shortwave antenna, my Sony reel AN-71 does a better job. Also, believe it or not my Sony AN-LP active antenna did a better job. I may have received a defective unit; I do not know. It does not pay to send it back to Banggood in China. I will just have to eat the price I paid for it. I should have investigated more thoroughly before I purchased it, but there were not any reviews to go by. Once again, please do not waste your money on this antenna.