If you have access to a 3D printer this might be an inexpensive alternative: https://youtu.be/qAgF9Mzr8XM or https://youtu.be/S6spyk1GRoo Personally, I'd go with the version that has a slight taper.
Yes ... that. Nickle has about 4 times worse electrical conductivity compared to copper, and the skin depth at 30 MHz is about 20 times thinner (about 12 microns for copper versus about 0.65 for nick
I believe that is likely to be a more efficient approach than using an inductor. It is possible to make air wound inductors with pretty high Q and not much loss, but the approach you used spreads th
Yeah, amplifier coils are a different animal than antenna loading coils. Lots different circuit impedance and lots different current levels. Still, his point is valid if you use a tank coil for a co
Jeff, you apparently didn't even bother to check out the guy's website. Here is a direct quote from it: "These coils are suited for amateur and commercial applications, including but not limited to
ChatGPT mostly agrees with you, except that it says that nickel with a high phosphorus content is almost impossible to solder to even when using an aggressive acid flux. Dave AB7E I remember lookin
The guy who makes the nickel plated QCoils has his email address on his website, so I just sent him an email asking him what the plating actually is. Hopefully he answers. Dave AB7E _______________
I guess that's why we call ourselves amateurs ... Dave AB7E _______________________________________________ _______________________________________________ TowerTalk mailing list TowerTalk@contestin
Well, it wasn't a waste from my point of view and I appreciate your search. I learned stuff I didn't know before. Take care, Dave AB7E Thanks for straightening us out! 73, Mike W4EF...............
I remember that as well. Well over $100 for even a moderately sized coil. That's why I came up with the do-it-yourself 3D printed concept that I posted here a few days ago. I can make exactly the
Before he retired, my oldest son used to write software for this sort of thing. He told me that with eight synchronous antennas he could beam form in any direction ... up/down and left/right. And o
I believe those are passive boxes, not DSP (somebody please correct me if I am wrong). They work fine, but are pretty expensive. Dave AB7E The DX Engineering NCC-1 and NCC-2 are excellent phasing
I don't own an RSPDuo and I have no commercial association with SDR Play ... although I do own an RSPdx and an RSP1B. The RSPDuo does have separate front ends, but the two receivers are fed from the
Yes, that's definitely true. In addition to a couple of NanoVNAs and an HF-CIA, I own an FA-VA5 designed by DG5MK that also works with the DG8SAQ software. By the way, it is possible to achieve the
And in turn, there is a lot of great information and advice your post, Rick. I'm archiving it. Take care, Dave AB7E On 9/7/2025 12:55 PM, Richard (Rick) Karlquist wrote: Great article Gary. It wa
I can't claim all of the following perspective to be based upon much practical experience, but from a theoretical point of view I lean toward the following as an ideal case: 1. A common mode choke a
Except that "ground" isn't actually some sort of sink for RF. Imagine a portable battery operated setup with a dipole antenna and nothing about the rig connected to ground. A common mode choke will
That's a fallacy. It simply isn't. Dave AB7E _______________________________________________ _______________________________________________ TowerTalk mailing list TowerTalk@contesting.com http://
I already did with the example of a floating portable setup. Current requires an E-field to push it. You could connect a grounded wire to a point on the coax shield and it wouldn't shunt any common
RF is AC ... whatever current goes toward ground comes back every half cycle. It doesn't just go into the ground and disappear. You aren't bleeding off a static charge that happens to be referenced