If you want all the hairy details behind why the screen works and how it performs compared to conventional wire radials, I recommend you watch my original magic carpet video. ua-cam.com/video/UadUg5H8KO8/v-deo.html
I have a Ham friend in town that did the faraday cloth with a metal foot tripod, with a 5 foot 20m ham stick. He was running a Zeigu 20 watt radio. He got good swr, and from NE Oklahoma he talked to Corpus Christi, Texas, New Jersey and Ohio while I was there. So I got my 10 foot tripod out and connected a 20m ham stick on top of it. I then a added a 12 gauge wire with small battery clamp connectors on either end of the wires. The 12 gauge wire was a little over 10 feet long, one end connected the antenna coax bracket on top of the tripod, the other end connected to the faraday cloth. Using a Yaesu FT-891 and a MFJ manual tuner, with 95 watts; I got really good swr and talked to few East Coast stations and tried to fight through a pile up from a Hawaii station coming in 5x7. I’m sold on the faraday magic carpet.
I just bought some, and plan on taking it out and trying it POTA soon. Besides the other pros to it, I like that it doesn't take up as much ground room like 33' radials do, and less things to worry about that someone will trip on my antenna layout.
Recently replaced my metal roof, and using ALL of the original roof (from the early 1900's) on the ground: (1) it kills the bamboo I have been trying to get under control that someone else planted years ago (2) makes the most rad ground plane ever (3) doubt someone will be able to sneak up to my windows at night - the sound of walking on metal is LOUD! With my Wolf River + ground radials, it makes a totally rad ground plane!
_Yoink!_ Not only did I just order that fabric, I'm going to copy your bypass wire! I think I'll put grommets in the corners of the cloth, though, so I can stake it down. I'll just double up on the stakes and use them for a couple of guy strings. (I have Photographers' sandbags for when I can't drive stakes.) I've got the Wolf River "TIA" antenna for the big gun, and an inexpensive Chinese 40-6m vertical that's similar.
Well, that was 6 months ago, did you have a chance to test it yet? How did it go? Do the grommets work? Would you buy the cloth again? I’m about to make this.
Thanks for all the good work you do Michael. You’re one of my favourite channels. I can’t believe I haven’t already subscribed! I fixed that quick and look forward to more of your excellent videos….
In my original 'magic carpet' video we did WSPR testing between wire radials and window screen material and found no loss in performance between the two, and saw a slight boost in performance as we added more material. ua-cam.com/video/UadUg5H8KO8/v-deo.html In field testing over the last six months, I've observed signal reports to be the same with the screen material as with the wire radials.
Michael, have you tried putting two Faraday cloths together side by side to improve the ground plane on 40m? Use a couple of wire jumpers with clips to electronically connect both cloths together. It may still need a ground radial or two on 40M and may provide some benefits on 80m..
Adding a second cloth will increase the performance of the lower bands, notably 80 meters. I've done that for low band operation with my vertical whip and Wolf River Coil, and it does make a difference.
Good stuff! I’ll be trying this, now people at the park will have to really put some effort to trip on my radials. They will anyway, but it’s going to be harder. 73!
Last summer on Independence Day, we were at the beach area of a small lake. We got there early enough to snag a picnic table under a shade tree. I had the vertical and window screen set up a good ten feet away from the paved path and people still managed to run into it.
You inspired me to try- purchased off of Amazon, and it’s quite the game changer. I appreciate your videos, content, and dedication. It’s difficult to find prime material today, aside from the few of you who do ham right!!! Thank you again, and 73 DE Andrew K7RXT
New Tech here. Very well done on the SWR testing and field run. Working toward General, just got the FT891. Have been looking for portable gear setup - thanks for all the links! KK7SAB 73
I wonder how a Space Blanket, the full size one with grommets, would work? That's silvered or metallic mylar fabric on one side, IIRC. Not the same as the disposable ones--which might be worth looking at.
This is why every day I look for your inside and knowledge. I have one question. I did not see you ground the faraday cloth to the base of the antenna. I am assuming that just by setting the tripod on the faraday cloth gives sufficient contact to complete the antenna system. I did notice that the faraday cloth did roll over in the breeze. You mentioned that you would be putting s few grommets in the corners to keep it flat and deployed. I was thinking a few very large washers glued to the cloth in the corners. Thank you for sharing this with us, and thank you for your UA-cam channel.
Thanks again for another great video. The worst part of pota is untangling ground plane wires. I use a copper stake for my sporty fourty and whip so I'll put a large homemade grommet dead center made of 2 pieces of aluminum riveted through the cloth and attach a power pole wire to one of the rivets. I like the idea of tent spikes on the corner. KD2RLB, 73
Sounds good probably end up getting that eventually I'm just getting back into ham so I'm trying different stuff but I like the idea of the cloth thank you
Michael, thank you for the information on the Faraday cloth, I was just going to get some screening material until I seen your video regarding the Faraday cloth, and for compactness this seems to the "ticket". Thank you for sharing and until next video, have a great day.
I have a Faraday cloth waiting for me at the house. I will break it in for a Radio merit badge class and JOTA/JOTI on Saturday. Thanks Michael! 73 KR5EBS
It would be less durable for regular use, but if you needed to save even more weight and space for a backpacking trip I suspect you’d get similar results from an aluminized mylar emergency blanket.
This is essentially a ground plane. What are your test numbers (SWR, etc.) without the screen compared to the screen? Need before and after with and without screen. Using a field strength meter. And actual signals from other Hams.
My original video on the windows screen ground plane, which is referenced in the video description, goes through all the stats, numbers, and performance metrics that you are looking for. Performance was the same between the screen and the cloth, so I didn't recreate all that data a second time: ua-cam.com/video/UadUg5H8KO8/v-deo.html
I have been using this in multiple configurations including very similar to yours. I am a big believer and have had pretty great results. Most importantly, it takes up no space! Thanks for the video! 73 KF0LTY.
Experiment with a circle of cloth or a square. Help reduce any directional effect. Try using it length way different directions. See if you get any directional benefits
The shape of the cloth really doesn't make a different. It's surface area coverage that you need to be concerned about. According to Robert Sherwood's May 1977 article in Ham Radio Magazine, you need at least a 1/4 wave of material in order to affect directivity: ia903006.us.archive.org/12/items/hamradiomag/ham_radio_magazine/Ham%20Radio%20Magazine%201977/05%20May%201977.pdf
I want it ! I'm all about man portable QRP. A light weight package with fast set up and tear down times. Been looking for a cloth like screen that doesn't cost a fortune. Going to check the prices on this. Also love RG8X. It's a little heavier and stiffer than RG58 but for 5 W operations every dB counts for telephony.
I'll have to give this a shot. I have been using window screen for a while. Attached thin wood molding to the ends to make roll-up easier (those edges get prickly) but would love to fold it to put in my antenna bag.
Huge fan of the window mesh and really like this idea too. Do you have a lead going clipped to the cloth as well or is your stand just sitting on it. I can't really tell.
@@KB9VBRAntennasThank for this update. Fascinating! I’ve used the screenwire as you have but it was really windy recently so I fastened down the corners using aluminum tent pegs (lightweight) and hooked up both the pegs and screen. Works wonderfully well. Probably overkill. Also, the Amazon link in your video for the faraday cloth says to not wash it except sparingly and gently and to not dry it in the sun. So, is this a problem to consider? N4LWT. 73
We were doing this 40 years ago Using hog panels. On my ranch I had a vertical, I used 8 hog panels tied together on the ground underneath it to form a ground plane, it worked really well. What I don't understand is with all those trees why in the world are you using a lossy vertical, i'd understand it for 40 and 80 meters but for anything under 40 you'd be much better off with a wire in the trees. I have a little drone that I keep with me specifically for launching wire antennas into trees good it has a payload release mechanism on the bottom of it that drops a weighted line over the top of the tree and allows me to hoist up antennas.
This concept has been around for a long time. In my research for the video I found a magazine article from 1977 that confirms the same things we found with the ground screen (link in the video description). AM broadcasters have been doing similar things for even longer. As for using a vertical antenna for the low bands, I use a wide variety of styles of antennas and will often pick the best tool for the job. Sometimes trees aren’t available to hang wire or the park has restrictions. Space may also be an issue. In many cases a 1/4 wave vertical with a good ground network will perform as good or better than an end fed half wave on the upper bands, and can be easier and quicker to deploy than a dipole.
It will be interesting to try this where I live in South West Western Australia....you run a magnet across the ground and half of the ground follows you around. Looks nice and light for SOTA work...cant wait to try it. 73 de VK6MMB
Just so I understand, I'm using a PAC 12 antenna. Will this cloth replace the radials that come with it, or is it used with the radials. Thanks. Love your channel. 73, KM4PMP
Oddly enough, I tried this and was unable to get a remotely decent SWR. The lowest I could get on any band was about a 1.9:1, and that took some doing. With 12 16' radials it works like a charm, but with the Faraday cloth, not so much. I may have to mess with it some more and see what I can do, but as of now it won't get the job done.
I've noticed that ground conductivity can have an effect on the window screen or cloth. It may just be the location. Try a different spot and see if you get the same results.
Thanks for bringing this to our attention. 😀 To always aim for zero reactance is incorrect guidance. One should always shoot for minimum SWR, regardless of the ratio of reactance to resistance. This keeps extra feeder-loss, owing to reflected power, to a minimum. Reactance is lossless. (However, perfect match is, of course, achieved at 50 Ohm resistive and zero Ohm reactance, in a 50 Ohm system).
Indeed! That is a concept which is also important to bear in mind. But I don't think that changes anything which I have written above? 73! Tim@@KB9VBRAntennas
www.merriam-webster.com/dictionary/snark Your first sentence and the emoji fits the definition. My sarcastic response does too. Having to explain all this also counts as such.
I am using the 17 foot Wolf River telescoping antenna, along with 18 16.5 foot radial wires. I have found that adding the additional radials dropped my SWR quite a bit, easily within operating range for any band between 6-40 meters. I purchased an aluminum window screen last weekend, just haven't tried it out yet. I will get a Faraday screen like the one in your video, and also pick up the same antenna mount that you are using in this video. Thanks!
I've also had very good luck with lots of little radials. That's what led me to testing and using the screen, as I surmised that surface area coverage is more important than radial length.
Hey thanks for this - a new one for me as I am always looking to improve antenna performance with just 10 watts allowed by my licence. The bonus is that might wife says if I buy a big bit she will line my hat for me with the excess 🙂. 73 M7BLC.
From other replies here I understand as long as you get continuity they should work. After Ive read through the rest of the comments here Im off into the garage to test the foil blankets I have in my first aid kit
These smaller pieces of material really don't offer any directivity. You would need a quarter wave or more of material for that to happen. In using the window screen for the last six months, I've found the contact patterns to be quite similar and typical for my geographic location.
In Wisconsin we suffer from very poor ground conductivity due to the high amount of granite bedrocks. I've found the window screen method to be a bit more forgiving. In some locations I'd be constantly tweaking radials, but with the screen, the match came easier. Not perfect, but easier.
Be careful on the length of the lead from mesh/cloth to tripod. I took the mesh portable with my WRC and SWR was 7:1 until I realized my lead had uncoiled. Coiled it back up and it was fine.
Purely resistive feedpoint impedance does not mean all the power is radiated. Full 1/4 wavelength vertical monopole antenna has a radiation resistance of about 36 ohm, so if your total resistive component is 50 ohm, the ground loss of 14 ohm is in the series circuit to make the total of 50. That 14 ohm is a pure loss and not radiated. With a loading coil, the antenna's radiation resistance drops rapidly, very often around 5 ohm range, so a good SWR is actually an indicator of warming the ground rather than good radiation. Also, the measurement is influenced by the presence of the coax. The best way to measure is to use a very short coax pigtail for measurement. The next best is to use a very low loss coax carefully adjusted cut at exactly 1/2 wavelength (electrical length, factoring the actual velocity factor, not the nominal catalog spec number). Obviously, the former is easier in multi-band antennas.
I looked online but I couldn’t find out how well this will hold up in a permanent application like buried just below the grass for say a hustler 5btv antenna.
I imagine it would deteriorate pretty fast as it is fabric and the wire is pretty thin. I'd use something more substantial like hardware cloth for direct burial.
Here you go: Heil Ham Radio BM-17 Dual headset: heilhamradio.com/product/bm-17-2/ How I record my contact audio: ua-cam.com/video/tOqzZPphE7k/v-deo.html My headset trigger switch: ua-cam.com/video/b5Wu8BlrSF0/v-deo.html
Noticed the complaints about edges fraying. You can buy an inexpensive bottle of "fray check" at any sewing counter, or online. Run it around the edges, and the fiber won't fray. It is like a super thin flexible glue. Or you could buy faraday tape, or duct tape, and just fold that over the edges for a heavier anti-fray solution.
I'm trying to get the Sporty Forty coil to work with my 213" whip. Did this work on 40m? I didn't see any QSOs with 40m. I have tried 5x 35' radials. WRC FAQ mentioned that 3 would work, but more are better. I had enough wire for five radials. That did not work. I was going to the hardware store for screen material, but this product looks easier to carry for POTA.
I'm using the Heil BM-17 dual headset with a home brew PTT handswitch. Here's the videos: My headset trigger switch: ua-cam.com/video/b5Wu8BlrSF0/v-deo.html Heil Ham Radio BM-17 Dual headset: heilhamradio.com/product/bm-17-2/
It depends on your base or tripod. If you have good continuity to the ground side of the antenna through the base, then you can set it directly on top of the cloth.
When using that Faraday cloth or window screen, is it better to have the antenna lower to the ground instead of being on a tripod and 6 feet in the air?
How much power can you put into the faraday cloth? Will it handle 100 watts? 1000 watts? Thinking of VK3YE and his pedestrian HF mobile - faraday toga? ⚡ Trailing cape like a superhero? 😁 Cool idea!
100 watts no problem. I don't know about 1000. I usually run 50 watts in the field. I wouldn't have any concerns with wearing it as a toga and running QRP portable.
I tried using duct tape for the fraying on the window screen but it wouldn't stick well and comes off, whereas on the Faraday fabric it works great to stop the fraying.
Can you address the cloth and screen affect on pattern? SWR and pattern are so.ewhat independent. I know there is a trade off in the infinite ground plane and a vertical vs small magic carpet, it would be good to put this too although I know ease of measurement is hard. Thanks for all your hard work and discovery! De WO8USA🇺🇸🇺🇸🇺🇸
On an anecdotal level, I haven't noticed a difference in antenna pattern with using radials vs using the screen. Operating at the same location with both ground systems, I seem to always seem to have the same pattern. In reading about ground networks, I've found that you typically need a pretty large radial network in order to affect directivity. That means lots of radials all bunched up on one side of the antenna. That same holds true with the screens. In the May 1977 Ham Radio Magazine article by Robert Sherwood, he mentions that screens need to be about a 1/4 wavelength in length before directivity is established: ia903006.us.archive.org/12/items/hamradiomag/ham_radio_magazine/Ham%20Radio%20Magazine%201977/05%20May%201977.pdf
Are there any comparable numbers with four radial wires? It works but how much better? Looks easier than spreading wires and is more visible to anyone close by.
In my original 'magic carpet' video we did WSPR testing between wire radials and window screen material and found no loss in performance between the two, and saw a slight boost in performance as we added more material. ua-cam.com/video/UadUg5H8KO8/v-deo.html In field testing over the last six months, I've observed signal reports to be the same with the screen material as with the wire radials.
I'm still using the Heil BM-17 headset. Here's some resources on my headphone setup and how I record transceiver audio: How I record my contact audio: ua-cam.com/video/tOqzZPphE7k/v-deo.html My headset trigger switch: ua-cam.com/video/b5Wu8BlrSF0/v-deo.html Heil Ham Radio BM-17 Dual headset: heilhamradio.com/product/bm-17-2/
Very interesting. Brings up a few questions in my mind plus some experiments I may do for fun. Could you see any change in SWR as the wind blew the cloth? I wonder how the SWR (impedance) changes as you roll up (make the area smaller) the fabric. I also wonder what the change is as you increase the spacing to the “dirt”. (How far the grass and leaves holds the fabric (I look at it as a capacitor plate) above the soil. I have been meaning to take some readings on my radials to gather some data. I may need to include some fabric in the mix. 73, de N4DJ
What headset are you using and what brand of magic carpet do you suggest for 10-80 I have regular wolferiver coil , got replacement coil but found my lost coil
I really like the concept but do you think that either the screen or the faraday cafe work just as well if it's either cut to a perfect square or folded over into a perfect square? I ask this because I believe if it works the square would take up much less space on the ground and maybe make a more compact fold. Thanks again for these wonderful videos. 73 KN4MXZ
I don't believe the shape of the cloth or screen makes a difference. It's the surface area coverage that matters. A smaller screen will work fine on the upper bands, but for 40 meters and lower, you will need more surface area.
I love this idea. I have been using the screen, a 17 foot whip and the wolf river tripod and this has worked great. It is quick to put out but a little clumsy. I am wondering if you could reduced the size (window screen or cloth). I am pretty sure that the smaller, the less effective. I saw a cloth that was 44 inches square and I thought I would try it. What do you think is a good size. Thanks for the great videos.
It appears that the amount of surface area you can cover makes a difference, especially on the lower bands. I've received reports that the smaller 36x44 pieces of cloth are adequate on 20 meters, but don't work well lower than that. My window screen is 36x84, and it works well on 40m and up. So maybe there is a number between 44 inches and 108 inches that's the perfect size.
Portable # (in this case Portable 4) is a bit of an antiquated term, but what the other person is saying is that they are operating outside of their normal callsign district. For example, if a person's callsign is K9XYZ and their are in the #4 call district (or any other district for that matter), announcing that they are portable tells you they are outside of where they normally operate. The FCC required this at one time, but the practice was largely given up when you where no longer required to have a callsign from the district in which you reside. For example, if you moved to another state in another callsign district, the FCC required you to change your call to that district. This is no longer the case. The Portable operation designator somehow still sticks, but it is not required.
The cloth won't fully attenuate RF signals, but it does lower them. The way RFI gets into computers is often through the cables, so common mode chokes would probably be more effective.
Thank you. I have ferrite beads on all cables and power cords. I might go the route for my computer’s monitor. On some bands it is affected by the transmission from the radio when using an random wire antenna. The transmission is much closer than a dipole on coax.
If you want all the hairy details behind why the screen works and how it performs compared to conventional wire radials, I recommend you watch my original magic carpet video. ua-cam.com/video/UadUg5H8KO8/v-deo.html
I predict hats of this cloth, way more comfortable than tin foil. Thank you though, this is a better way to antenna.
They are already made. Search the Internet.
Would that come in cowboy style.
Just asken
Lol hats of this material that’s primo!
😂@@DCDura
This is something I will try. I hate screen material but faraday is a lot more forgiving in use. Good job!
It certainly folds up into a smaller package, which is really nice.
I have a Ham friend in town that did the faraday cloth with a metal foot tripod, with a 5 foot 20m ham stick. He was running a Zeigu 20 watt radio. He got good swr, and from NE Oklahoma he talked to Corpus Christi, Texas, New Jersey and Ohio while I was there. So I got my 10 foot tripod out and connected a 20m ham stick on top of it. I then a added a 12 gauge wire with small battery clamp connectors on either end of the wires. The 12 gauge wire was a little over 10 feet long, one end connected the antenna coax bracket on top of the tripod, the other end connected to the faraday cloth. Using a Yaesu FT-891 and a MFJ manual tuner, with 95 watts; I got really good swr and talked to few East Coast stations and tried to fight through a pile up from a Hawaii station coming in 5x7. I’m sold on the faraday magic carpet.
Activated 4 parks, 3 new to me, with the faraday cloth. So easy! I threw it over the bed of the pickup on for 3 new parks.....worked great!
Still the best online Elmer any ham can have! Great video Michael!
Grommets and tent stakes sounds like the way to go. Good idea.
I just bought some, and plan on taking it out and trying it POTA soon. Besides the other pros to it, I like that it doesn't take up as much ground room like 33' radials do, and less things to worry about that someone will trip on my antenna layout.
Love it.... Thanks for a no BS straight up analysis of this cloth.... I'm going to buy some now. Great video
Michael just took us on a magic carpet ride!
Thank you Michael. You have great ideas and are a great Elmer for Ham radio. Can’t wait to make a contact using your idea.
I want to try 3 30' tape measures connected with allegator clips. Easy to put out and store.
Recently replaced my metal roof, and using ALL of the original roof (from the early 1900's) on the ground: (1) it kills the bamboo I have been trying to get under control that someone else planted years ago (2) makes the most rad ground plane ever (3) doubt someone will be able to sneak up to my windows at night - the sound of walking on metal is LOUD! With my Wolf River + ground radials, it makes a totally rad ground plane!
_Yoink!_ Not only did I just order that fabric, I'm going to copy your bypass wire! I think I'll put grommets in the corners of the cloth, though, so I can stake it down. I'll just double up on the stakes and use them for a couple of guy strings. (I have Photographers' sandbags for when I can't drive stakes.) I've got the Wolf River "TIA" antenna for the big gun, and an inexpensive Chinese 40-6m vertical that's similar.
Grommets area good idea. I guess I need a grommet tool now.
Well, that was 6 months ago, did you have a chance to test it yet? How did it go? Do the grommets work? Would you buy the cloth again? I’m about to make this.
Thanks for all the good work you do Michael. You’re one of my favourite channels. I can’t believe I haven’t already subscribed! I fixed that quick and look forward to more of your excellent videos….
I loved this thanks.
I’ve been using the Faraday cloth for about a month now, works great , going to put some grommets into it for some spikes so it won’t fly away. KB2GCG
I found that using fishing weights were a much easier alternative and didn’t seem to have any negative affect
Great find. Use a Faraday bag for my car keys and credit cards. Works great. But now, this is a great idea. Thanks for the tip.
I thinks we would need to see the data without the faraday cloth for comparison. Not sure. You are the man. Great work.
In my original 'magic carpet' video we did WSPR testing between wire radials and window screen material and found no loss in performance between the two, and saw a slight boost in performance as we added more material. ua-cam.com/video/UadUg5H8KO8/v-deo.html In field testing over the last six months, I've observed signal reports to be the same with the screen material as with the wire radials.
Michael, have you tried putting two Faraday cloths together side by side to improve the ground plane on 40m? Use a couple of wire jumpers with clips to electronically connect both cloths together. It may still need a ground radial or two on 40M and may provide some benefits on 80m..
Adding a second cloth will increase the performance of the lower bands, notably 80 meters. I've done that for low band operation with my vertical whip and Wolf River Coil, and it does make a difference.
Looks like it works as good as the window screen. Thanks for sharing.
A great afternoon at the park!
Thanks! I just ordered one
I think I need to get some of this. Looks much easier than try to keep a lot of ground radials from tangling and deploying them.
Yes, I posted my results on another comment that the faraday cloth works!
Hopefully, neighbors will not call the cops on you, Michael 😂 Most everything us hams do could look strange to them, if you know what I mean😂😂
I haven't had a problem yet. Although I am pretty sure all my neighbors think I'm crazy.
Well done as always! 73!
Good stuff! I’ll be trying this, now people at the park will have to really put some effort to trip on my radials. They will anyway, but it’s going to be harder. 73!
Last summer on Independence Day, we were at the beach area of a small lake. We got there early enough to snag a picnic table under a shade tree. I had the vertical and window screen set up a good ten feet away from the paved path and people still managed to run into it.
You inspired me to try- purchased off of Amazon, and it’s quite the game changer. I appreciate your videos, content, and dedication. It’s difficult to find prime material today, aside from the few of you who do ham right!!! Thank you again, and 73
DE
Andrew K7RXT
New Tech here. Very well done on the SWR testing and field run. Working toward General, just got the FT891. Have been looking for portable gear setup - thanks for all the links! KK7SAB 73
Excelent Info. Thanks NP4VO Jose 73s
I wonder how a Space Blanket, the full size one with grommets, would work? That's silvered or metallic mylar fabric on one side, IIRC. Not the same as the disposable ones--which might be worth looking at.
If the blanket offers continuity or an electrical connection to the ground side of the antenna, it should work.
Thanks for the info.
This is why every day I look for your inside and knowledge. I have one question. I did not see you ground the faraday cloth to the base of the antenna. I am assuming that just by setting the tripod on the faraday cloth gives sufficient contact to complete the antenna system. I did notice that the faraday cloth did roll over in the breeze. You mentioned that you would be putting s few grommets in the corners to keep it flat and deployed. I was thinking a few very large washers glued to the cloth in the corners. Thank you for sharing this with us, and thank you for your UA-cam channel.
I laid the antenna base directly onto the cloth. It made a direct connection so I didn't need to add any jumper wires
There have been some people adding grommets to the Faraday cloth to assure a ground plane.
Thanks again for another great video. The worst part of pota is untangling ground plane wires. I use a copper stake for my sporty fourty and whip so I'll put a large homemade grommet dead center made of 2 pieces of aluminum riveted through the cloth and attach a power pole wire to one of the rivets. I like the idea of tent spikes on the corner. KD2RLB, 73
Sounds good probably end up getting that eventually I'm just getting back into ham so I'm trying different stuff but I like the idea of the cloth thank you
Michael, thank you for the information on the Faraday cloth, I was just going to get some screening material until I seen your video regarding the Faraday cloth, and for compactness this seems to the "ticket". Thank you for sharing and until next video, have a great day.
I have a Faraday cloth waiting for me at the house. I will break it in for a Radio merit badge class and JOTA/JOTI on Saturday. Thanks Michael! 73 KR5EBS
Nice, I gotta give this a try!
...And it will keep you warm and cozy on those cold
Wisconsin nights. Thanks for the video from K1NEO, Maine.
It's a bit sparkly too, so I feel very fashionable.
Expert activation! You don't often get to hear a pileup in the videos.
I was thinking the same thing.
It would be less durable for regular use, but if you needed to save even more weight and space for a backpacking trip I suspect you’d get similar results from an aluminized mylar emergency blanket.
Add the FC-50 to that ET-891. Just finished hooking mine up, "easy peasy!"
I just got one. Hope to try it this weekend
How did it work for you? I’m ordering some tomorrow.
It works great
@@N4GW thank you for the update.
This is essentially a ground plane. What are your test numbers (SWR, etc.) without the screen compared to the screen? Need before and after with and without screen. Using a field strength meter. And actual signals from other Hams.
My original video on the windows screen ground plane, which is referenced in the video description, goes through all the stats, numbers, and performance metrics that you are looking for. Performance was the same between the screen and the cloth, so I didn't recreate all that data a second time: ua-cam.com/video/UadUg5H8KO8/v-deo.html
OK thanks. Ill check it out. 73
I have been using this in multiple configurations including very similar to yours. I am a big believer and have had pretty great results. Most importantly, it takes up no space! Thanks for the video! 73 KF0LTY.
Faraday cloth.. Brilliant! 73!
Experiment with a circle of cloth or a square. Help reduce any directional effect. Try using it length way different directions. See if you get any directional benefits
The shape of the cloth really doesn't make a different. It's surface area coverage that you need to be concerned about. According to Robert Sherwood's May 1977 article in Ham Radio Magazine, you need at least a 1/4 wave of material in order to affect directivity: ia903006.us.archive.org/12/items/hamradiomag/ham_radio_magazine/Ham%20Radio%20Magazine%201977/05%20May%201977.pdf
I want it ! I'm all about man portable QRP. A light weight package with fast set up and tear down times. Been looking for a cloth like screen that doesn't cost a fortune. Going to check the prices on this. Also love RG8X. It's a little heavier and stiffer than RG58 but for 5 W operations every dB counts for telephony.
I was just at the same park a week ago or so. Did a quick activation and then found a few pounds of oyster mushrooms. 😉 cool place for sure.
It's a nice park and I only live 20 minutes away. You should have given me a shout.
I'll have to give this a shot. I have been using window screen for a while. Attached thin wood molding to the ends to make roll-up easier (those edges get prickly) but would love to fold it to put in my antenna bag.
Huge fan of the window mesh and really like this idea too. Do you have a lead going clipped to the cloth as well or is your stand just sitting on it. I can't really tell.
I laid the antenna base directly onto the cloth. It made a direct connection so I didn't need to add any jumper wires
@@KB9VBRAntennasThank for this update. Fascinating! I’ve used the screenwire as you have but it was really windy recently so I fastened down the corners using aluminum tent pegs (lightweight) and hooked up both the pegs and screen. Works wonderfully well. Probably overkill.
Also, the Amazon link in your video for the faraday cloth says to not wash it except sparingly and gently and to not dry it in the sun. So, is this a problem to consider? N4LWT. 73
We were doing this 40 years ago Using hog panels. On my ranch I had a vertical, I used 8 hog panels tied together on the ground underneath it to form a ground plane, it worked really well.
What I don't understand is with all those trees why in the world are you using a lossy vertical, i'd understand it for 40 and 80 meters but for anything under 40 you'd be much better off with a wire in the trees.
I have a little drone that I keep with me specifically for launching wire antennas into trees good it has a payload release mechanism on the bottom of it that drops a weighted line over the top of the tree and allows me to hoist up antennas.
This concept has been around for a long time. In my research for the video I found a magazine article from 1977 that confirms the same things we found with the ground screen (link in the video description). AM broadcasters have been doing similar things for even longer.
As for using a vertical antenna for the low bands, I use a wide variety of styles of antennas and will often pick the best tool for the job. Sometimes trees aren’t available to hang wire or the park has restrictions. Space may also be an issue. In many cases a 1/4 wave vertical with a good ground network will perform as good or better than an end fed half wave on the upper bands, and can be easier and quicker to deploy than a dipole.
It will be interesting to try this where I live in South West Western Australia....you run a magnet across the ground and half of the ground follows you around. Looks nice and light for SOTA work...cant wait to try it. 73 de VK6MMB
Grommets. 👍
Just so I understand, I'm using a PAC 12 antenna. Will this cloth replace the radials that come with it, or is it used with the radials. Thanks. Love your channel. 73, KM4PMP
Ooh-La-La! 👍
Do you still use radials with the carpet .
Can we place the magic carpet between the roof of a vehicle and a tri mag mount? Would it improve signal strength or is it overkill on a steel roof?
Great question hoping you get a reply
Oddly enough, I tried this and was unable to get a remotely decent SWR. The lowest I could get on any band was about a 1.9:1, and that took some doing. With 12 16' radials it works like a charm, but with the Faraday cloth, not so much. I may have to mess with it some more and see what I can do, but as of now it won't get the job done.
I've noticed that ground conductivity can have an effect on the window screen or cloth. It may just be the location. Try a different spot and see if you get the same results.
@@KB9VBRAntennas Will do. Thanks!
Maybe a grommet in the middle as well for use with a spike mount.
I've seen people put cutouts and grommets in the center of their cloth.
Great video Michael. I am learning a lot from you. Thanks
Next up- chain link fence. Not terribly portable but when one is present...
Thanks for bringing this to our attention. 😀 To always aim for zero reactance is incorrect guidance. One should always shoot for minimum SWR, regardless of the ratio of reactance to resistance. This keeps extra feeder-loss, owing to reflected power, to a minimum. Reactance is lossless. (However, perfect match is, of course, achieved at 50 Ohm resistive and zero Ohm reactance, in a 50 Ohm system).
Since you seem to appreciate snark, I'll just respond by saying that a dummy load also presents a perfect match.
Indeed! That is a concept which is also important to bear in mind. But I don't think that changes anything which I have written above? 73! Tim@@KB9VBRAntennas
P.S. As an Englishman, I'd be fascinated to know the meaning, in this context, of "snark"; it's not a word in usage over here. 😀
www.merriam-webster.com/dictionary/snark Your first sentence and the emoji fits the definition. My sarcastic response does too. Having to explain all this also counts as such.
Ah, thanks for the definition :-) Apologies if my comment(s) seemed snarky; that wasn't my intetion.
I am using the 17 foot Wolf River telescoping antenna, along with 18 16.5 foot radial wires. I have found that adding the additional radials dropped my SWR quite a bit, easily within operating range for any band between 6-40 meters. I purchased an aluminum window screen last weekend, just haven't tried it out yet. I will get a Faraday screen like the one in your video, and also pick up the same antenna mount that you are using in this video. Thanks!
I've also had very good luck with lots of little radials. That's what led me to testing and using the screen, as I surmised that surface area coverage is more important than radial length.
Hey thanks for this - a new one for me as I am always looking to improve antenna performance with just 10 watts allowed by my licence. The bonus is that might wife says if I buy a big bit she will line my hat for me with the excess 🙂. 73 M7BLC.
How about using a foil emergency blanket these are bigger and a lot cheaper I have tried one and seems ok but maybe not as good as Faraday cloth
From other replies here I understand as long as you get continuity they should work. After Ive read through the rest of the comments here Im off into the garage to test the foil blankets I have in my first aid kit
Perhaps lay a second one perpendicular on top and create a X. It may give a better omni directional pattern.
These smaller pieces of material really don't offer any directivity. You would need a quarter wave or more of material for that to happen. In using the window screen for the last six months, I've found the contact patterns to be quite similar and typical for my geographic location.
It would be interesting to see how it works in the Seattle area (K-3216, K-3261, etc) where I have to adjust the radials for every band change
In Wisconsin we suffer from very poor ground conductivity due to the high amount of granite bedrocks. I've found the window screen method to be a bit more forgiving. In some locations I'd be constantly tweaking radials, but with the screen, the match came easier. Not perfect, but easier.
What do you think that I would do better without a faraday cloth in North Carolina near the coast?
What would the effects be if the ground plane were on a thin bed of water?
If using a non metallic tripod, would you run a wire from the antenna somewhere to the ground network?
I'd run at wires, from the ground side of the tripod to the screen or cloth. It seems the more connections you make, the better the match.
Be careful on the length of the lead from mesh/cloth to tripod. I took the mesh portable with my WRC and SWR was 7:1 until I realized my lead had uncoiled. Coiled it back up and it was fine.
What is the RF loss-angle of the fabric? 😀
Purely resistive feedpoint impedance does not mean all the power is radiated. Full 1/4 wavelength vertical monopole antenna has a radiation resistance of about 36 ohm, so if your total resistive component is 50 ohm, the ground loss of 14 ohm is in the series circuit to make the total of 50. That 14 ohm is a pure loss and not radiated. With a loading coil, the antenna's radiation resistance drops rapidly, very often around 5 ohm range, so a good SWR is actually an indicator of warming the ground rather than good radiation. Also, the measurement is influenced by the presence of the coax. The best way to measure is to use a very short coax pigtail for measurement. The next best is to use a very low loss coax carefully adjusted cut at exactly 1/2 wavelength (electrical length, factoring the actual velocity factor, not the nominal catalog spec number). Obviously, the former is easier in multi-band antennas.
can any material block ELF? i heard metal shielding might.
I looked online but I couldn’t find out how well this will hold up in a permanent application like buried just below the grass for say a hustler 5btv antenna.
I imagine it would deteriorate pretty fast as it is fabric and the wire is pretty thin. I'd use something more substantial like hardware cloth for direct burial.
Mike, what headset with microphone are you using, and what are you using to key your radio?
Here you go:
Heil Ham Radio BM-17 Dual headset: heilhamradio.com/product/bm-17-2/
How I record my contact audio: ua-cam.com/video/tOqzZPphE7k/v-deo.html
My headset trigger switch: ua-cam.com/video/b5Wu8BlrSF0/v-deo.html
Good demo!
Might want to check KE9TT/4 QTH if you haven't done so already. Definitely not Virginia Beach!
Noticed the complaints about edges fraying. You can buy an inexpensive bottle of "fray check" at any sewing counter, or online. Run it around the edges, and the fiber won't fray. It is like a super thin flexible glue.
Or you could buy faraday tape, or duct tape, and just fold that over the edges for a heavier anti-fray solution.
Thanks for the tip. My wife had a bunch of Jo-Ann coupons so I got some Fray Check and iron on hem tape to finish the edge of my cloth.
I'm trying to get the Sporty Forty coil to work with my 213" whip. Did this work on 40m? I didn't see any QSOs with 40m. I have tried 5x 35' radials. WRC FAQ mentioned that 3 would work, but more are better. I had enough wire for five radials. That did not work. I was going to the hardware store for screen material, but this product looks easier to carry for POTA.
Thanks for the video. What headset / PTT switch are you using with the FT-891?
I'm using the Heil BM-17 dual headset with a home brew PTT handswitch. Here's the videos:
My headset trigger switch: ua-cam.com/video/b5Wu8BlrSF0/v-deo.html
Heil Ham Radio BM-17 Dual headset: heilhamradio.com/product/bm-17-2/
As always great Video. I don’t see a connection from the stand to the cloth. Is it not needed?
It depends on your base or tripod. If you have good continuity to the ground side of the antenna through the base, then you can set it directly on top of the cloth.
A 2m quarter wave mag mount on the roof of a car is insulated from the metal roof, so maybe an electrical connection isn't essential.
Enjoying your videos! My last piece of equipment for POTA is a laptop, what program are you using for logging your contacts? Thanks
Dave
W4FSW
I'm using Hamrs (www.hamrs.app) on an inexpensive Windows PC
What size was the mat you were using in the video
Three yards, 44x108 inches. There's a link to it in the video description.
When using that Faraday cloth or window screen, is it better to have the antenna lower to the ground instead of being on a tripod and 6 feet in the air?
Lower is better. The screen or cloth seems to lose its effectiveness as you raise the antenna above it.
Do you have a alligator clip to a wire and a connector going to the carpet ?
No. My antenna base makes good contact and maintains continuity between the cloth and the ground side of the antenna.
Can i use this method to increase ground plane on my Truck topper, for a permanent vertical antenna setup?
I've seen people with fiberglass roofs on their RVs do something very similar with metal screens to create an appropriate ground plane on the vehicle.
Do you have to make sure you get "reflective" vs "absorbant" fabric - I'm looking at using it for a folding parabolic EME dish.
Hi Dan, I think that you have a good point; see my comment regarding RF loss-angle 😛
How much power can you put into the faraday cloth? Will it handle 100 watts? 1000 watts?
Thinking of VK3YE and his pedestrian HF mobile - faraday toga? ⚡ Trailing cape like a superhero? 😁
Cool idea!
100 watts no problem. I don't know about 1000. I usually run 50 watts in the field. I wouldn't have any concerns with wearing it as a toga and running QRP portable.
I tried using duct tape for the fraying on the window screen but it wouldn't stick well and comes off, whereas on the Faraday fabric it works great to stop the fraying.
Can you address the cloth and screen affect on pattern? SWR and pattern are so.ewhat independent. I know there is a trade off in the infinite ground plane and a vertical vs small magic carpet, it would be good to put this too although I know ease of measurement is hard. Thanks for all your hard work and discovery! De WO8USA🇺🇸🇺🇸🇺🇸
On an anecdotal level, I haven't noticed a difference in antenna pattern with using radials vs using the screen. Operating at the same location with both ground systems, I seem to always seem to have the same pattern. In reading about ground networks, I've found that you typically need a pretty large radial network in order to affect directivity. That means lots of radials all bunched up on one side of the antenna. That same holds true with the screens. In the May 1977 Ham Radio Magazine article by Robert Sherwood, he mentions that screens need to be about a 1/4 wavelength in length before directivity is established: ia903006.us.archive.org/12/items/hamradiomag/ham_radio_magazine/Ham%20Radio%20Magazine%201977/05%20May%201977.pdf
Are there any comparable numbers with four radial wires? It works but how much better? Looks easier than spreading wires and is more visible to anyone close by.
In my original 'magic carpet' video we did WSPR testing between wire radials and window screen material and found no loss in performance between the two, and saw a slight boost in performance as we added more material. ua-cam.com/video/UadUg5H8KO8/v-deo.html In field testing over the last six months, I've observed signal reports to be the same with the screen material as with the wire radials.
What's that headphone setup you are using? Or have you switched to something else?
I'm still using the Heil BM-17 headset. Here's some resources on my headphone setup and how I record transceiver audio:
How I record my contact audio: ua-cam.com/video/tOqzZPphE7k/v-deo.html
My headset trigger switch: ua-cam.com/video/b5Wu8BlrSF0/v-deo.html
Heil Ham Radio BM-17 Dual headset: heilhamradio.com/product/bm-17-2/
Very interesting. Brings up a few questions in my mind plus some experiments I may do for fun.
Could you see any change in SWR as the wind blew the cloth? I wonder how the SWR (impedance) changes as you roll up (make the area smaller) the fabric. I also wonder what the change is as you increase the spacing to the “dirt”. (How far the grass and leaves holds the fabric (I look at it as a capacitor plate) above the soil. I have been meaning to take some readings on my radials to gather some data. I may need to include some fabric in the mix.
73, de N4DJ
What headset are you using and what brand of magic carpet do you suggest for 10-80 I have regular wolferiver coil , got replacement coil but found my lost coil
Why not use a Mylar sheet ( space blanket ) as the ground plane?
You could, as long as you can get continuity from the ground side of the antenna.
I really like the concept but do you think that either the screen or the faraday cafe work just as well if it's either cut to a perfect square or folded over into a perfect square? I ask this because I believe if it works the square would take up much less space on the ground and maybe make a more compact fold. Thanks again for these wonderful videos. 73 KN4MXZ
I don't believe the shape of the cloth or screen makes a difference. It's the surface area coverage that matters. A smaller screen will work fine on the upper bands, but for 40 meters and lower, you will need more surface area.
I love this idea. I have been using the screen, a 17 foot whip and the wolf river tripod and this has worked great. It is quick to put out but a little clumsy. I am wondering if you could reduced the size (window screen or cloth). I am pretty sure that the smaller, the less effective. I saw a cloth that was 44 inches square and I thought I would try it. What do you think is a good size. Thanks for the great videos.
It appears that the amount of surface area you can cover makes a difference, especially on the lower bands. I've received reports that the smaller 36x44 pieces of cloth are adequate on 20 meters, but don't work well lower than that. My window screen is 36x84, and it works well on 40m and up. So maybe there is a number between 44 inches and 108 inches that's the perfect size.
Could either the screen or the faraday cloth be used on top of snow ? Would it still work?
Yes it will. I've placed the screen on top of 8-10 inches of snow and it worked just like sitting on bare ground.
Thank you ! Your help very much appreciated 👍
It didn't look like you put the radials on did you?
No. The purpose of the ground screen or cloth is to eliminate the need for radials.
What does portable 4 mean out there please? Heard someone call in with callsign then portable 4?? Thanks
Portable # (in this case Portable 4) is a bit of an antiquated term, but what the other person is saying is that they are operating outside of their normal callsign district. For example, if a person's callsign is K9XYZ and their are in the #4 call district (or any other district for that matter), announcing that they are portable tells you they are outside of where they normally operate.
The FCC required this at one time, but the practice was largely given up when you where no longer required to have a callsign from the district in which you reside. For example, if you moved to another state in another callsign district, the FCC required you to change your call to that district. This is no longer the case. The Portable operation designator somehow still sticks, but it is not required.
Can you use the cloth to cover computers and power supplies? It might be effective and blocking RFI for digital operations.
The cloth won't fully attenuate RF signals, but it does lower them. The way RFI gets into computers is often through the cables, so common mode chokes would probably be more effective.
Thank you. I have ferrite beads on all cables and power cords. I might go the route for my computer’s monitor. On some bands it is affected by the transmission from the radio when using an random wire antenna. The transmission is much closer than a dipole on coax.