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• First half up to minute 38 is a bit of a history on how the efhw arose, starts with the zepp. Talks about longwires fed by 9:1 unun. EFHW stuff starts at 38 min and you could probably skip to here and not miss much. Quite easy to watch at 2 times speed.
• Steve mentions that he is not an EE or considers himself to be an antenna expert rather someone who has been experimenting with antennas for a long time.
• Steve dissects a myantennas efhw 8010. See attached snippet from the video.
• Grounding methods are discussed. Recommendation is to ground at the transformer and again at the radio end for max measured current. Note he uses a version for 20m for this test. See snippet pic for his summary.
• Uses same 20m version to compare with a dipole version and compares radiated rf. Note that this is not far field.? Steve finds EFHW equal to the dipole version in this test.
• Beyond just an EFHW Steve shows how to add 160M (and 60M and 6M).? Requires an extensive ground system which sort of defeats one of the attractions of the EFHW.? See pic. The schematic drawing in the video does not have a cap that was needed so I have added it.? Blue lines represent the cap which Steve says needs to be 0.0015pf (this does not seem right to me). Note this cap and schematic is only required for the extra bands.? Potentially 60M and 60M could be reached with a tuner??? I don't know.
• 75M option.? As constructed the antenna resonated in the lower end of he 80M band. Add a cap (250pf - 500pf) at the half way point to resonate at 75M without impacting the other bands.
• Compensating coil. The antenna resonates most bands at the upper end of the bands, ie phone end.? if you want the CW end of the bands add a coil, 5 turns of 14ga enamel copper wire on 1 inch coil 72 inches from the transformer.? See snippet (from another video).

开云体育

开云体育

Hello Kees,

Are you planned to ship outside US ?

if yes, please 1 pcb of each for me.

vy’ 73s de Jacques – F1APY

?

I bet some find it hard to stomach buying $27 plastic panels for a $10 plastic case when?debating a few bucks differences in micro-controllers.
That said, my building brother, I too get anxious on cutting holes.? We don't know what tools you have, and given the question, assume not a mill or a drill press.
What I would do is cover the front side of the plastic panel with blue 3M painters tape. Scribe the centerline for the holes directly on the 'inside the box' portion of the plastic where it won’t be seen.?I use center drills to start the holes (they are cheap), if you don't have center drills, use a small drill bit.? Once the initial undersized holes are cut, flip the piece over and drill from the 'outside the box' side so if you get a chip out it won't be seen. Best to start small and step up to one drill bit less than size.?When drilling, secure the plastic panel over a scrap piece of softwood, and make this a "pine board project."? With thin plastic and drilling with hand tools, I find that the final drill bit size is best done by hand. I have an old pcb hand nibbler tool ($10?)? for cutting somewhat square holes with patience.? ? Just slightly undercut the rectangle for the LCD with the nibbler, remove the tape and finish out with a bastard file and sand paper.? If all goes wrong, you?can still try 2 more cases or spend the $27.? Also search this forum for good ideas on printing a full face 'label' which might cover up the sins of a nonperfect cut. Stain grade or paint grade? My wood working Grandfather taught me very early in life that a coat of paint covers a multitude of sins. Nothing ventured, nothing learned. Maybe someone else has some tips.