Thanks for the test. However, the mini-whip is being unfairly treated: it needs to be up and away from any walls, roof, etc. to work properly, and then it really works great. I live on the top floor of an apartment building and extend my mini-whip horizontally out about 2m from the window of my home office / hobby workshop. This means that it is fairly high up (5th floor), and away from the building structure. Under these conditions it tests much better than my 60ft long wire, all the way up to over 10mhz, and especially much better on BC band. Over 10mhz, the long wore is slightly better, but not by much. I guess this could well be a perfect apartment antenna. I'm really happy with mine. Thanks again for the videos.
I have a mini-whip here and where it really shines is listening to the frequencies below 500 Khz for me. I can even hear the WWV signal s-9 most evenings on 60 Khz with that but not a thing at all with my long wire antenna or anything else I have. Also a lot of Nav beacons I can hear down there that I can't with my wire antennas or dipoles.
Sounds great, yes, it works well for me down there but on HF, sometimes it is better and many times not. Works pretty well for me on the AM broadcast band also!
I'm getting similar results with the Mini Whip Vs. my 85 feet end fed long wire. Although the Mini Whip does better on much lower frequency into longwave. The long wire is much better for shortwave than the Mini Whip. Much more tinkering involved with the Mini Whip, it's well grounded. I would like to place on a higher location. Thank you for the video.
Hi Kevin, thanks again for an interesting video. I thought I'd run a spice simulation on the mini whip circuit to see what happens when you drop the supply voltage, because I wondered how and why a voltage follower with a voltage gain of 1 would be affected by the supply voltage. What happens at 6V is that the JFET J310 has an insufficent voltage to be biased properly. The drain-source voltage becomes very low and the J-FET stops functioning as intended. So what is perceived as a low gain is in fact the circuit kind of shutting down. I simulated with a few millivolt signal source producing two frequencies, 7 and 10MHz. At a low supply voltage the intermodulation products increase significantly as the J-FET saturates. Maybe not the best way to reduce the effect of strong broadcast stations.
Yeah, the way to reduce the broadcast stations is with a notch filter. Interestingly, in my previous video where I was first testing the mini whip kit, I was supplying it via the built in biasT in the SDRPlay RSP2. The voltage is 4.7 Volts at the connector, and by the time you got down the coax to the circuit, it was just a tad under 4 volts. Still a lot of gain though. You can see the signals just leap up when I enable the voltage.
Kevin Thank You For Taking The Time to make such interesting videos.I am studying for my ham licence here in Canada your videos keep my interest in getting my Ham Ticket so again Thank U
Last comment was six years ago? I would have thought many hams would view this video. While your test is fine for your specific application, others have to know more details. The type and length of coax; the construction and height of each antenna; the direction of their major lobes; the obstacles near them and the way each is grounded? Is your long wire attached to a tuner? I see many videos of hams doing tests, but few ever describe the setup. Every ham or SWL will have a completely different setup. A true test would place all the antennas in the same location, positioned for maximum lobes to be in the same direction, grounded at the same point with the same type and length of coax. A common tuner/preselector set to maximize the signal at the desired frequency for each antenna would also make sense.
Prediction, mag loop has least noise, best s/n, some direction; mini whip most noise worst performer, long wire medium noise but good across all bands. Time to watch... surprised how badly the loop did, I have an Alex Loop, it's pretty solid, did a 5w phone qso to a Turkey with it in 2012. The station on AM is WLS, a pre selector will work wonders on AM, I have a video on it with a CR 1a and an MFJ SW tuner.
maybe compare WWV on 2.5, 5 , 10, 15 Mhz etc. rather than just 10 Mhz and medium wave. I suspect the smaller amplified antennas may do better the higher in frequency you go and the wire lower. Interesting .
I've been told that mini-whip antennas need 'good grounding.' That's sort of subjective. How much grounding is enough? One ground rod? Two? Three? Four? Can I connect it to one ground rod, and then run copper from one ground rod to another ground rod? Or should the antenna be connected to each ground rod with its own separate ground wire?
Miniwhip must be mounted on an earthed metal pole at least two metres long (above conducting obstacles) and as far as possible from metal conductors. Generally the higher the better as the E field tends to be attenuated close to the ground. When mounting on a metal pole it is important the top of the pole is below the Miniwhip's amplifier otherwise there will be capacitive losses. A good example of a well sorted Miniwhip in action is the University of Twente's SDR at: websdr.ewi.utwente.nl:8901/
@@tglenn3121 Hi, I bought one of the Ukrainian sourced pre built miniwhips. It came with specific instructions for mounting, that's where metal pole came from. I also isolate mine by using a ferrite core on deadline close to antenna. University of Twente has got one of these working well see websdr.ewi.utwente.nl:8901/
