Fault Finding: Sigma Euro-Comm LW20 End Fed Long Wire Antenna and 9:1 Unun SWR - Ham Amateur Radio
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- เผยแพร่เมื่อ 1 ต.ค. 2024
- So, I purchased a new Sigma Euro-Comm LW20 End Fed Long Wire Antenna, but the SWR was high, and was every changing. I tried everything to find the fault, and finally got it - a capacitance issue in the Unun due to an air space caused by hot glue melting the wire!
Ben, my advice is keep the 20m long wire and buy a 49:1 transformer. Connect it up and you have 4 bands: 40 20 15 10 no tuner needed. It will knock the 9:1 out of the park. 73
that was my though :-)
Ah, thanks Tim. Great advice. I shall pick one up!
Agreed and depending on if the 9:1 is potted or not maybe you can simply convert it by rewinding with coil for 49:1 instead - also sounds like it might be a good idea for a video :P
Also rather than attach a dummy load get a resistor of the correct amount for the balun and then test for 1:1. For example with a 9:1 it would be about 450 ohms (9x50) and for a 49:1 it's usually about 2.5K. You can do this with the radio by setting the power to 5-10w and then key up on FM and check the SWR. Good for peeps with no analysers.
Great idea! Thanks for watching.
Da lord does work in mysterious ways
I purchased this from Myantenna EFHW-7510-2K-Plus - EFHW-7510-2K+PLUS with Pole Installation Plate X 1 and its been great its also an end fed.
Nice videos, next time put a 450 ohm resistor on the antenna connectors. That's what a 9 to 1 is looking for. That said the 9to1 are very inefficient, try a 49:1 or and L Match.. they will open your eyes. 73
Where did being a ham require slating me in your IGNORANCE. Ben stated it's a 9to1 unit. A 9to1 is looking for 450 ohm. You are referring to an end fed transformer which is a completely different animal.. DO YOUR RESEARCH
Personally, I would have checked the unun first. But that's just me, since I've had problems with ununs.
Köszönöm, nagyon örülök, hogy ezt a videót megcsináltad!
Thanks, I'm so glad you made this video!
From my understanding of antennas I would have thought a 49-1 would have been a better choice due to high impedance on End-Fed wire, and a 9-1 would be better suited to a Random wire. But well done on the detective work. Shaun M3ULT
You removed a tree on your friend's advice? What if your friend said that your house may be the problem?
OMG, a 20m wire IS TUNED! It is resonant as l/2 in 40m and l/4 on 80m.
Yes, this is designed to work on all bands from 80-6, so needs a tuner for some bands.
It is probably about 21.5m which is good for 10-80m and can also work on 6 and 160 with a good tuner (well, mine does!)
After you fixed it did the icom 7300 internal aut work with it
Great video are u getting commission lol 😆
What has happened to Ben nothing in a year. Hope all is well.
well done for putting this on here,
Great job Sherlock! 73.
Another really interesting video Ben. I've got the same long wire antenna on its way (currently being held captive by UPS) for my first HF rig along with a Xiegu X90. I hope I don't have the same problems you do. Great detective work there though! 73.
Sounds great! Let me know how you get on with it.
Excellent troubleshooting and that’s why we love this hobby.
73
WD4DDA
Hello! Congrats for being so stubborn! It definitely payed off! I'm thinking to buy this antenna to use it for portable QRP with a Xiegu 5105 (or the new x6100). These radios have an internal tuner. Do you think will it be enough to tune the antenna on 40-20-30-17-12-20 meters?
WOW.... poor tree just for touching your antenna. Let's hope a family member or your wife doesn't touch it in the future. They will end up like the tree. 🏴☠️🏴🏴Great video.
Motters
M7TRS 73's
Lol. It needed to go, it was an Ash tree 2 meters from the house... they grow massive!
@@RadioRevG5REV you just wanted to make room for the antenna, hi hi. I am new to ham and your channel. Great work. My direction with Ham will probably be QRP/HF and SOTA. Just starting off with a anytone 878 uhf/vhf and DMR M7TRS 73's
Keep up the good work Ben. As we are now in tier 4, you will need to look after the analyser and unun for a little while longer. If I need it before then, I know where you live...
Thanks Steve. Speak to you at 8 on GB3SA? 73
hm I have the same one just hung it up in my backyard. 13m down from the roof and then turn into and L so not a straight line. Mine also has the last part of the L so to speak in some branches. Now mine works fine on all bands even 80m but only on 40m is the SWR skyhigh... not a clue why as of yet ? ;-)
Very good detective work and amateur radio sportsmanship. Keep up the good work!
Hope you don’t mind me asking but are you a Pastor or a reader of theological books??
Well spotted, yes, I'm a pastor (Church of England Vicar) - always happy to talk about faith in Jesus. 73.
Hi 👋
I have some of the books you have on your shelf. Banner of Truth are also easy to spot 👍God bless you and your ministry. ❤️
Glad you figured out the problem. Hope that tree will grow back up.
Thanks for watching. The tree was a beech tree, and was growing 2m from the house. Beech trees are massive when fully grown. Instead, I shall plant a tree in a more appropriate place! 73
@@RadioRevG5REV I agree. The sprawling roots will be no good for the house.
That’s GREAT detective work, Ben. And also great that you defined the ATU as an Antenna MATCHING Unit - the term Antenna TUNING Unit (ATU) is the biggest con in the Ham radio hobby that Hams still fall for! A truer description might even be Impedance MATCHING Unit (IMU)!
Great that you also impressed that an internal ATU should only handle a maximum of 3:1 SWR, i.e. when using an antenna that is close to resonance anyway. I know many a Ham who has regularly exceeded that limit and “burned out” their internal ATU. Most Hams should use an external ATU unless they absolutely know their antenna is less than 3:1 on the band they are using.
Just Sod's Law ref the duff unun, eh?! A really great and clearly expressed video, Ben.
Dem low cost parts is the work of the devile