EXCELLENT! Peter -- I finally got around to building this, and this afternoon I set it up and made adjustments. I found some lightweight 1.5 inch diameter plastic pipe and wound that with #22 enameled magnet wire. I started with 36 close-spaced turns and ended up with 33 turns very slightly spread to achieve 34 microhenries. I attached an alligator clip to one end and about 2m of wire on the other. I put up my 20m EFHW wire that I use for portable operation (it's #22 stranded, insulated) then clipped the coil to the end. After adjusting the length of the 40m add-on I ended up with a 2:1 SWR bandwidth of about 125 kHz on 40m and flat, less than 1.3:1 across 20m. Works great and much more compact than my full size 40m EFHW wire. (Last summer I tried to make a compact 40m antenna by cutting my 20m wire in the middle and adding a coil using the shortened dipole formulas. Not only did it not tune up well on 40m, but that concept requires lowering the antenna to switch bands. This is so much better.) 👍
Peter thanks so much for your very helpful videos! Here's another low-cost multi-band antenna option. I have a Xeigu G90 (yes, a great low-cost transceiver) feeding 3 watts into a Xeigu XPA125B 100-watt amplifier. I use the XPA125B amplifier's very robust built in ATU with this antenna and can get an SWR of 1.7 to 1 or better on all bands 160 - 10 meters, including WARC bands. My antenna is a 71-foot end-fed non resonant sloper. The high end is 15 feet going down from a balcony railing to a wooden fence about 6 feet high, with a slight dog leg at the low end to follow the fence line. It's fed from the high end using a 9:1 unun and 50 feet of RG8x. Because the coax feedline braid acts as a counterpoise I have a common mode choke between after the XPA125B amp into the coax feedline. I've made SSB contacts on all phone bands, working stations in Japan, Australia and the US East Coast from California and I regularly check in to 40 and 80 meter nets with good signal reports. I agree that antenna modeling doesn't always show actual antenna performance. Could you possibly do some comparison A/B testing of small garden resonant and non-resonant antennas? Much appreciated!
Hi Jon. Yes interesting arrangement. I did s video on the 9:1 UnUn. I found the longer the wire the better, and as you have found, the long length of coax helps. There is the problem of a high VSWR on the coax on some bands, but the loss is not likely to be too much if you play around with the length. Well done. Take care. 73 Peter.
I have a similar setup except it is longer and covers 10-40 (haven't checked resonance on inbetween bands) and 80 with the coil. I can't reccomend efhw antennas enough. Space saving, great results and cheap to make. Not to forget can be made small enough to use portable!
Well said..nothing like getting a 5/9 after spending as little as possible on an antenna then experimenting with position,longer,shorter how to make it higher.To me is all part of the fun of the Hobby.
Very interesting discussion of modeling. At one point I used a handheld log periodic for portable satellite operations. The 2m operation was fine, but the 70cm had a very definite notch in the response. I found that off pointing 15-20 degrees made a significant improvement in the 70cm signal. Not my personal measurement, but someone with the right equipment reported the notch as about 2dB deep.
Hi Peter, I have such an antenna and use it mounted vertically on my spiderpole with the 34uh coil slipped over the pole itself and it works a treat. Good for the DX !
Thank you Peter… love your channel excellent entertainment and fun too 👍… using previous information supplied by yourself I made this antenna for 40m with loading coil for 80m which worked really well (in fact I purchased a loading coil from you guys then made one for fun)… as I also have a compact garden for a 90 degree angle I used some upvc tube and put a flat top at the inverted v apex so increasing the angles … not sure from a theoretical stand point how it impacted the performance of the antenna but it worked and gave me 80m in a compact garden. Thanks again for sharing. … Dave M7DFM
Hi Peter, I have the same 2m/70cm antenna as you (bought from W&S of course) and I have exactly the same results as you regarding the polar diagram. Very well made, lightweight and low wind resistance. 73 Ken G3WNR
Thank you for the video, a question if I may. With the coil fitted and 40m resonant does that also make it resonant on the 15m harmonic? This making it a quad band antenna? I’m guessing No as I think you would have told us, thanks again Peter great video.
Hi Peter, than you about your last video, very nice and interesting. I have the same space problems, but I don't have a small garden but a balcony. Which antenna do you suggest? Thank you in advance! 73
Hi there. I am assuming the balcon is above ground level. One option would be to fasten the EFHW transformer on the wall of the building -say just above the outer door and at one side of the balcony. Then take the wire diagonally across to the other other side but at the front of the balcony, and then run the wire down towards the ground. I don't know how much space you have so cannot really go further on that. Hope to helps. 73 Peter.
Hi peter love watching your videos,always look forward to the next one,a question for you is would a loading coil work for 80 meters at the 49.1 transformer end as im using a 20 meter length of wire so i get on 40 and 20 already, so to reiterate from the transformer about 2 meters then the loading coil then the 20 meter wire,the reason i ask this my end fed is already up high in a tree many thanks Tony
EXCELLENT! Peter -- I finally got around to building this, and this afternoon I set it up and made adjustments. I found some lightweight 1.5 inch diameter plastic pipe and wound that with #22 enameled magnet wire. I started with 36 close-spaced turns and ended up with 33 turns very slightly spread to achieve 34 microhenries. I attached an alligator clip to one end and about 2m of wire on the other. I put up my 20m EFHW wire that I use for portable operation (it's #22 stranded, insulated) then clipped the coil to the end. After adjusting the length of the 40m add-on I ended up with a 2:1 SWR bandwidth of about 125 kHz on 40m and flat, less than 1.3:1 across 20m. Works great and much more compact than my full size 40m EFHW wire. (Last summer I tried to make a compact 40m antenna by cutting my 20m wire in the middle and adding a coil using the shortened dipole formulas. Not only did it not tune up well on 40m, but that concept requires lowering the antenna to switch bands. This is so much better.) 👍
Great news William. Glad to hear your results. 73 Peter
@@watersstanton I had a chance to test it on the air today with my KX2. It "worked a treat." 😀
Brilliant as usual Peter, thanks 73 Robert G3RCE
Many thanks! 73 Peter
Thanks Peter, wasn't expecting you to say the Discovery was back in stock... just brought one now!
Hi Alan, you will love it. I use mine a lot. Take care. 73 Peter.
Peter thanks so much for your very helpful videos! Here's another low-cost multi-band antenna option. I have a Xeigu G90 (yes, a great low-cost transceiver) feeding 3 watts into a Xeigu XPA125B 100-watt amplifier. I use the XPA125B amplifier's very robust built in ATU with this antenna and can get an SWR of 1.7 to 1 or better on all bands 160 - 10 meters, including WARC bands. My antenna is a 71-foot end-fed non resonant sloper. The high end is 15 feet going down from a balcony railing to a wooden fence about 6 feet high, with a slight dog leg at the low end to follow the fence line. It's fed from the high end using a 9:1 unun and 50 feet of RG8x. Because the coax feedline braid acts as a counterpoise I have a common mode choke between after the XPA125B amp into the coax feedline. I've made SSB contacts on all phone bands, working stations in Japan, Australia and the US East Coast from California and I regularly check in to 40 and 80 meter nets with good signal reports. I agree that antenna modeling doesn't always show actual antenna performance. Could you possibly do some comparison A/B testing of small garden resonant and non-resonant antennas? Much appreciated!
Hi Jon. Yes interesting arrangement. I did s video on the 9:1 UnUn. I found the longer the wire the better, and as you have found, the long length of coax helps. There is the problem of a high VSWR on the coax on some bands, but the loss is not likely to be too much if you play around with the length. Well done. Take care. 73 Peter.
I have a similar setup except it is longer and covers 10-40 (haven't checked resonance on inbetween bands) and 80 with the coil.
I can't reccomend efhw antennas enough. Space saving, great results and cheap to make. Not to forget can be made small enough to use portable!
Yes agreed. Thanks for sharing. 73 Peter
Well said..nothing like getting a 5/9 after spending as little as possible on an antenna then experimenting with position,longer,shorter how to make it higher.To me is all part of the fun of the Hobby.
Many thanks. 73 Peter
Very interesting discussion of modeling. At one point I used a handheld log periodic for portable satellite operations. The 2m operation was fine, but the 70cm had a very definite notch in the response. I found that off pointing 15-20 degrees made a significant improvement in the 70cm signal. Not my personal measurement, but someone with the right equipment reported the notch as about 2dB deep.
Thanks for that Alan. Take care. 73 Peter
Brilliant!
Thank you for the very practical advice.
73, from the USA
Glad it was helpful!
Hi Peter, I have such an antenna and use it mounted vertically on my spiderpole with the 34uh coil slipped over the pole itself and it works a treat. Good for the DX !
Good tip! I hooe to do some tests this year on EFHW verticals as I am sure tge grounded quarter wave is not tge answer for a small garden. 73 Peter.
Thank you, I am always looking for new ideas for antennas to fit my limited space.
Glad to help
Thanks Peter, enjoy these practical videos which relates to my situation. Great ideas.
Glad you like them! 73 Peter
Thank you Peter… love your channel excellent entertainment and fun too 👍… using previous information supplied by yourself I made this antenna for 40m with loading coil for 80m which worked really well (in fact I purchased a loading coil from you guys then made one for fun)… as I also have a compact garden for a 90 degree angle I used some upvc tube and put a flat top at the inverted v apex so increasing the angles … not sure from a theoretical stand point how it impacted the performance of the antenna but it worked and gave me 80m in a compact garden. Thanks again for sharing. … Dave M7DFM
Thanks Dave. Glad the antenna is working well. Sometimes we make changes with unexpected results. Take care. 73 Peter
Hi Peter, I have the same 2m/70cm antenna as you (bought from W&S of course) and I have exactly the same results as you regarding the polar diagram. Very well made, lightweight and low wind resistance. 73 Ken G3WNR
Thanks Ken. Yes nice sntennas. 73 Peter
Thank you for the video, a question if I may. With the coil fitted and 40m resonant does that also make it resonant on the 15m harmonic? This making it a quad band antenna? I’m guessing No as I think you would have told us, thanks again Peter great video.
No, because the coil acts as a choke on 15m. Sorry. 73 Peter
@@watersstanton any possibility of multiple traps?
Hi Peter, than you about your last video, very nice and interesting. I have the same space problems, but I don't have a small garden but a balcony. Which antenna do you suggest? Thank you in advance! 73
Hi there. I am assuming the balcon is above ground level. One option would be to fasten the EFHW transformer on the wall of the building -say just above the outer door and at one side of the balcony. Then take the wire diagonally across to the other other side but at the front of the balcony, and then run the wire down towards the ground. I don't know how much space you have so cannot really go further on that. Hope to helps. 73 Peter.
@@watersstanton Thank you Peter
Thanks for the video, Would a T2LT work if placed over the Apex of the roof ?
Yes unless it is placed low over a meta roof.73 Peter
Thanks Peter
Nice............. ❤️
Thanks 🤗
Need a bit more help with the 34uh coil can’t find much info on this .........
There are many calculators on the web - try this. 66pacific.com/calculators/coil-inductance-calculator.aspx
@@watersstanton thankyou
Would you also get 15m on this antenna as it is the 3rd harmonic of 40m? If so it's actually a Quad-Band Antenna!
No. That choke coil will block 15m. 73 Peter
@@watersstanton thanks for clarifying!
Hi peter love watching your videos,always look forward to the next one,a question for you is would a loading coil work for 80 meters at the 49.1 transformer end as im using a 20 meter length of wire so i get on 40 and 20 already, so to reiterate from the transformer about 2 meters then the loading coil then the 20 meter wire,the reason i ask this my end fed is already up high in a tree many thanks Tony
The only way to add 80m to your 20m length of wire is to add a loading coil at the far end I am afraid. 73 Peter
@@watersstanton @Yo Yes, I'm using that configuration. Inverted L with 110uH inductor toward the end. Works on 80m very well.