Portable Loop Antenna tuner demonstration (20m)
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- čas přidán 11. 09. 2024
- Here on / ng9d we spend a lot of time fiddling around with low power (QRP) radio transmitters, simple receivers, home-made wire antennas and various little gadget kits, celebrating perhaps the best hobby in the world - Ham Radio! In this video we look at a couple of representative 20m QSOs using A small loop antenna that is made using a toy hula hoop, an MFJ portable loop tuner and ten foot length of PVC tube. Total length of wire is about 12 feet including pig tails. The antenna system performs fairly well at 10 W power level on 20m. Next experiments will be on lower frequency bands 30m, 40m
(and maybe 80m). MFJ portable loop tuner is designed to match small loops less than about 3/16 wavelength to transceivers up to 25W. 73 Lynn/NG9D
MFJ recommended wire lengths:
Band Length (feet) Length (meters)
80-M 63.0 19.20
40 -M 28.0 8.53
30-M 20.0 6.96
20-M 13.0 3.96
17-M 9.0 2.75
15-M 7.0 2.13
12-M 5.5 1.68
10 -M 4.0 1.22
Just watched your vid of the loop on 18MHz - the signal strength on this loop is great - of course it's K5KV tho! Still, impressive!👍
I've been curious about this loop tuner. Hope you make a video on other bands as well. Great work!
Update: I found this ‘poor mans loop’ to work very well!
Very good demo! Seeing the written out message while listening to the code would be a good way to learn Morse code. I like that you pause for a tiny bit between words. Some people run all their letters together making it impossible to understand. Thanks for the demo!
thanks!
Excellent demo. Thanks for posting!
Props to a CW slinger who will slow down for a slower keyer. I notice how you pause your finger on the keyer base as well. Is that to keep your rhythm going?
73 de N0BPS (IL as well)
Hi Brian, thanks for the comment. I developed that finger pause habit to make clear separation between words. I don't know if it is a good habit since it is wasted motion, but on the other hand CW is like written language; ifthereisnoseparationbetweeenthewordsitishardertounderstandthemessage. - 73 Lynn
Well, there are many people who can say this is a good habit and that is a bad habit. I can say by watching you work that it obviously works well for you. Based on that, I would say its a good habit for you! :-) Makes complete sense as well. I have yet to begin learning CW but I did purchase two old practice oscillators for when I take the plunge. Got a nice Heathkit and an Ameco. I just like looking at them on my desk for the time being. lol. Hope to catch you on the air some time. 73
I appreciate your two videos on 20m. Any chance you've used this on other bands (e.g. 30/40m) and could leave some reviews online for it (i.e. eham.net)? I'm seriously considering this for my K2 but not much info out there or reviews. Thanks - Daniel/AA0NI
My case did not connect to the panel I had to reorder the screws
What key are you using here??
Hi, recently I bought this one and I wonder if I can make only one loop with 20 feet to improve some contacts from 40m to 10m, or ONLY with these 20 feet, I can tune for 40-30m... or if exists another way to solve my need to get a multiband antenna for those bands, what is the correct size? Thanks for sharing. 73 de PR7RC
Wow, I missed your comment so long ago. Well, maybe better late than never. I put comments on the wire lengths that worked best for me Ramiro. Hope this is helpful czcams.com/video/ujq6OBFPYoc/video.html 73 Lynn NG9D
can the feedline and tuner be brought indoors in case of rain? thanks
Hi vetham100. Feedline yes, tuner no. I have serious doubts this arrangement would be very satisfying. 73 Lynn NG9D
can you tune 20m to 10m with the loop??tnx for video lynn hope wrk u agn on cw..73' pierre ve2opb
+pierre bordeleau Hi! I found with about 12 to 13 feet of wire, in this video the tuner would match the hula hoop on 20 and 17m. I checked my notes, and didn't record any measurements on 10m. I have a feeling that the best length of wire for 28MHz would be about (1/4)(3/4)(300)/(frequency in MHz)=2meters, about 6.5 feet.
How long is the supplied cable? 73 de Daniel
+v4mp1 Hi Daniel. The black insulated wire I got with the MFJ-9232 portable is about 3/16 wavelengths on 80m or ≈50 feet. However, on this video the red wire is from another project and it has a length of 12-13 feet or so for the frequencies in this demonstration. Any insulated wire will do for experimentation. I notice in the current manual, wire is not mentioned so maybe they ship the tuner only. Contact MFJ for details. Here is link to manual file:///C:/Users/Lynn/Downloads/MFJ-9232manual_rev2.pdf 73 Lynn/NG9D
What gauge wire did you use
The one time I actually want captions and they're not available. :P
Ok, cool that you can do code, but ... 7 and a half minutes... kinda like hey folks, look at me... I can ride a bike... your time would be better served talking about the equipment you are using and demonstrating... Really, 7 minutes..
Hi Andrew, my channel is mainly for the entertainment of those who either know or are learning Morse code. 73 Lynn NG9D