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Outstanding, I live in Florida, I have seen videos on Faraday cloth which I have purchased, Easier than running radials when portable.

I assume the 80m slider will also tune 60m, 40m, and 30m?

Thank you

I think the message is watch your swr meter and stop if it starts going up. If it does consider a different toroid or stacked toroids. The watts going into the cores can also be worked out via back to back efhw toroids and two power meters, one each side Now do toroid baluns, ununs and chokes.

SUPER video!! As an engineer, I really appreciated the data plots which always provide so much more information than verbal descriptions of testing results. I am now subscribed.

Great information. Thank you. Very clear explanation. And I do not like math, but was able to follow everything.

I think the strength of your videos is your ability to explain very simply. I have subscribed and will look for your videos. Thank upi and 73 VP2MD

Thanks for the video. I live in Oregon which looks to be solid red. Once i get my radials trimmed and clamped up..i will report back

I assume i can leave the coil permanently attached to the base and the stringer to the coil., and when i want to use 20 thru 6M i just bypass the coil with a clip lead. That way i can also switch quickly between 20 and 40M, Kindly confirm that this wont pose any harm to the coil? 73 de k1jbd, Bammi

Grew up in nearby Huron. Left Ohio in 1975,became Ham 40 yrs. Later. Enjoyed video,especially Lake Erie History! 73 W7OT

Your quarry looks like my QTH, Leakey, Tx in the Texas hill country. To put a spike in the ground, I use a Dewalt hammer drill with a 1/2" masonry bit.

Hi Jim am I correct in my thinking. If you put this over an antenna coax cable you will only be able to measure the common mode current running on the outside of the braid. As the differential mode currents will cancel themselves out.

Didn't go to Hamvention, so thanks for bringing these products to our attention. Regarding the faraday cloth: i folded the edges, and secured the fold using the faraday tape which comes with the cloth. Keeps the edges from fraying. I also purchased a grommet kit (they are very inexpensive on Amazon), punched 8 grommets on the periphery of the faraday cloth, and lay it down and stick in small Aluminum tent pegs. Keeps the faraday cloth secure and in place, and holds well in fairly gusty winds. Also, i had mentioned in another video, several people here use chicken fence wire rolls, way cheaper than window screen and available in any length you want, works well too. I like the faraday cloth best because it fold up compact and is the lightest. Also carry 4 radials as a backup.

Thanks Jim, Very interesting topic like most of your videos and really marvel at the innovations you come up for the jigs for the metrics you are trying to measure. Curious about one thing: When you measured the ferrite code temperatures you ran the rig key down 100% duty cycle. Wouldn't a more realistic model use the duty cycle of say a digital mode - FT8 15s on / 15s off, or for FT4 shorter on/off cycles? Also, as you point out most transformers come in a enclosed box for weather/dust protection, or the QRP ones shrink wrapped around some sort of support like a winder (yes there are some unprotected ones wire wrap tied to a support. Keep them coming and we'll keep on learning. Thanks again 73 de k1jbd, bammi

tnx so much yr support at tech Knowledge Flow up your videos god bless you BR FM ıstanbul

Hello Jim, What Diodes are you using on your Slayer Exciter between the Emitter and Base? I'm using the diode UF4007.

Link is not working?

Nice effort but why use the lossy material, not enough core cross-section for 3.5MHz, and what myth is busted? I made hundreds of EFHWe transformers and pointed out hundreds of times that a single FT-240-43 is the worst possible design. There are real myths present and perpetuated by amateurs when it comes to designing RF transformers. The main reason why the cores are heating is lossy material and bad design just like the one used in the test with not enough primary turns for the 80m band.

You are a good teacher and experimenter. Thank you. VU2RZA

Hello Jim, Do I have to measure the Collector to Emitter voltage from Peak to Peak voltage or "Peak/Max voltage" with my oscillocope? The transistor datasheet shows the max Collector to emitter voltage as DC voltage, but the Primary coil has AC voltage, sinusoidal waveform. I hope you can help me.

Hello Jim, How Can I know what value to use for the Transistor Base Resistor, I'm using a Toshiba 2SC5200 NPN transistor, but it only works with a base resistor lower than or equals to 10K ohms.

Great video. Just found your channel. 73

Add a capacitance hat near the top of that stinger will improve the radiation resistance on 40m-80m

The ground screen off to the side like that will drastically affect the omni-directionallity of your vertical. Put the cloth in the direction you want to work.

Thanks for the nice walkthrough. While the stinger is a bit longer than the 17’ telescopic whip, it looks nice and robust and aluminum is a preferred material with less resistance. So if you put the capacitor in the circuit, since it connects to the tripod, it could be said that it tunes the ground system a bit (and then you further refine the total match with the inductor that’s in series with the whip)?

Hello Jim. How do you connect the oscillocope probe to measure the transistor collector voltage?

Thank you, Jim.

I like the simplicity of design, adjustability and ability to lower SWR shown in the video.

I'm not a fan of PVC pipe construction. Nonetheless, nice to see this application of variable inductive coupling and integration of a matching network -- what's old is new again.

Excellent very good presentation. I like the dip curves

Thanks for sharing your experaince and finding in this video. Do you have a video on your homemade coil. Can you share your design of your coil. Regards

Thank you ! I appreciate your work. Now I have to go build that dummy load for my Nano-VNA.

Thx Jim, eye opening !

Jim great information, just got a coil and a 17 ft whip. Your coil looks like a better coil. Can you share how to make one. I enjoy making my antennas. I tried slinkies, long wires, end feds, still looking for the one I like 73s AA2BD ps. I'm using a G90 20 watt radio.

I love your clarity of thinking speaking and measurement design and comparison math tables of the data..

excellent description Jim... you are a great instructor/teacher...and communicator... thank you...

This is poor quality control in the manufacturing. The manufacturer should be cleaning up that mold flashing!

Brilliant!

Hey jim,thanks so much for all your hard work.iam starting portable ops next week so this has helped so much.new subscriber 73

Jim, Stumbled on your channel, then had to binge watch all the ham radio videos, thanks for the excellent content and for sharing your knowledge and insights. Just as an FYI, i use chicken wire fence, much cheaper than the window screen. I just use clip leads to connect to the chicken wire. Look forward to your coil video. 73 de k1jbd, bammi

Now we need to test with more efficient cores and windings. 70-75% efficiency is pretty bad for a proper EFHW.

Compared to a regular windmill they are not very efficient. Standard style the blades are into the wind 100% of the time. VAWT will never be as efficient.

Great video sir, I do alot of POTA my results between actual wire radials and the screen or faraday cloth have been very minute differences here in central Indiana. I personally use the faraday cloth...( aprox 3' by 7') because the faraday cloth folds up to about a 5"x 8" , and is so much easier to deal with and transport.... no tangling wires or multiple wire spools to deal with. I can usually set my entire station up in a park in less than 6 minutes. Thanks again for all your work , the ionfo was very informative and useful. NS9T 73 sir.

Thank you for your knowledge

Wow! I own and use several and was looking at buying another for flour. Thanks!

nope! waaayyy-tooo "ungainly", sorry! keep on...tryin' 🙂tanx!!

Rubber shoes and straw brain

Great video ,Jim . I'm looking forward to seeing a video on your homemade coil . 73's

Can this tool read temperatures above 1000 degrees Celsius?

All i care about is if it keeps stink out😂..i got some stinky chemicals that need to be in a cool spot. So my home is the only cool spot i know of. Ziploc bags don't help. Was hoping this would do the trick. I mean if it will keep it paint fumes then it should be good enough. Maybe I'll get a normal cheap paint lid also just in case. I'll deal with the tool to get it off. Whatever. I jus need this stink to be gone.