INVERTED "L" ANTENNAS ` some neat Options and a Unique Trick!
HTML-код
- Опубликовано: 6 июн 2024
- The inverted "L" antenna has been one of the oldest and most popular antennas, particularly for the lower frequency ham bands. Peter G3OJV, takes a look at this antenna and highlights the many options for installing and feeding this antenna. One particular option is a unique way of feeding this antenna from the far end rather than from the base.
For all Your Ham Radio Needs
www.hamradiostore.co.uk 
Наука
The idea of feeding a vertical from the top always reminds me of the ones I saw in a HOA neighborhood. Two different length (1/4 wave) wires hanging down from a large oak tree limb, each with a dog bone insulator and a bird feeder attached below it to help hold it taught. Two coax runs went up the tree and out the limb to feed each vertical from the top. A clever and inconspicuous antenna installation. 73 de Dan WD4DB
Interesting! Let's hope the birds did not suffer from excessive RF exposure!
You by fair have the best ham videos on the internet
Nice to get your support. 73 Peter
Best instructor to explain it all very clearly. Thank you again.
You're very welcome!
Great idea Peter. Thanks and 73...W6QR
Very useful! Thanks, Peter.
Thank you for yet another excellent tutorial Peter. I have never thought of this configuration. Very welcome ideas! 73, Mike. M0MTJ
Glad it was helpful!
Nice video, thank you,I constructed an "L" antenna using lengths of 4 meters and 2.5 meters combined with a 9:1 or 49:1 balun, and it's performing exceptionally well across all bands including 80M band, having good height of 13m
Nice work!
Wonderful, useful information presented with class.
Glad it was helpful!
Wonderful idea! I would never have thought of this. ❤
Glad you like it!
When feeding from the upper floor window (with either a 49:1 or 9:1 located well above earth), with the radiating element going horizontal for a ways and then making the downward turn towards the grass out in the lawn/garden, you're suggesting that you might actually want to connect that radiating element (i.e., energized by the center pin of the coax) to a ground rod? Or you're suggesting that you would rather put radials at the ground level that are not actually connected to the antenna element itself (since the ground terminal is upstairs--either at the unun or at/near the radio)? While I'm not in the UK, thanks for your contributions to the hobby there commercially & otherwise, and in non-commercial form to those of us elsewhere!
Direct coax feed only at bass centre to element. For end feed the radials attach to antenna bass.
TY Peter what a wonderfull article you published..im tryin this .. 73 Sir
Many thanks.
Good explanations, thanks very much
Great video and great topic. Thanks much. Subscribed. Cheers from Florida, USA ...
Welcome aboard! Regards to you in Florida.
Brilliant video, thank you.very interesting.
Glad you enjoyed it
👍Thanks for video.
Great video on a great ant. If fed at the base, it's a great dx ant and very quiet on rx. Apparently there is 2000 ft in a average house hi.
I've use a inv L on 80m, it goes really well, even at 7m, as mine was.
73 zl3xdj
Thanks Brian. I guess we can add copper piping for central heating to that figure!! 73 Peter
I run a 80m efhw like this. It’s a cloud burner compared to the inverted V for 80. The noise level is very quiet on 40,20,15. I’ve used it on 160m as well but it’s not good there at all. I plan to revisit the orientation at higher max current elevations.
Hi there. Thanks for sharing.
Another great video. Can this be fed with ladder line.
From top possibly but interesting experimental project.
If you create a way to disconnect the antenna wire from the low earthed point and raise it a little then it becomes a true efhw which resonates on harmonics. The same antenna construction can then do 40/15m but also 20 by simply disconnecting the bottom.
I have a similar situation with a 40m efhw as inverted L, fed at the top with a 49:1. If I drop it down a little and add a few radials it resonates on 80m. I never optimized or used it as such but it does work.
Yes I was looking at that possibility but have nit had a chance to see whether the grounded resonant length on 40m translates perfectly to 20m when open circuit. In other words dies 7MHz become 14MHz or perhaps 14.4MHz etc.
@@watersstanton there is a good chance that the resonance is a bit off but that can be solved by either leaving a bit of the wire on the ground side, ie. have the disconnect slightly up the vertical section, or make the ground connection a little up the verticale wire, leaving a short unused stub in grounded configuration which adds a bit of length to the antenna in open config.
An option to draw a simple sketch in a YT comment would be such a handy feature 😀
Another thing I noticed when measuring the SWR over freq is that an inverted L doesn’t really give a good dip at harmonics, only on the base frequency. Maybe because of the L shape, a straight efhw gives a more pronounced dip at harmonics.
I was wondering if you could add an extra band using a trap? For example, would adding a 20m trap just above the ground connection effectively disconnect it from ground on 20m?
Hi Peter, love your videos but why do you draw the antenna as two pieces of wire. Confusing for newbies.
Good point! Will join them next time.
throw down some fence wire for your radials ive done it and it works rather well
Yes provided it can be sunk so that it is not a hazard when walking over it.
Yes a good option.
Is it illegal to put an antenna in the yard in England? I always hear everyone talking about putting antennas up in gardens. Wouldn't you have more room in the yard?
@TheTim16964 Yards are forbidden in England. Waters and Stanton advice Scotland Yard to put an inverted L in.
In the UK we refer to our house outside space as "gardens." In the USA you refer to them as yards. .
@watersstanton that makes sense, my question seems kind of silly now 🤭
If you ever heard a ham from Australia - you know the antenna can be fed from the top 😂
Nice one!
Mmmm….1/4 wave on 20M…might be workable for POTA
Yes, give it a go!
Not completely relevant to the topic under discussion but; I notice your digital pianos in the room you film in. I've recently been dabbling in 10m FM both simplex and via repeaters. Anyway after I put a call out on a repeater i could hear a bit of feedback/echo. Strange I thought, why can i hear my voice coming out of the speakers? I don't have the monitor facility turned on. Even more strange the power light on my digital piano is on, I'm sure I didn't turn the piano on, very strange! I turned to he piano off and carried on calling on the KQ2H repeater, but hang on I can hear myself again, the piano is turned on again too. It seems transmitting in FM on the 10m band is turning my piano on and my voice is coming out of the piano's speakers.
Easily remedied by turning the piano off at the mains, but thought you might find it funny! 73
inverted L vs pure vertical ?
Definitely the best👍
Robert G3RCE