I would like to measure the self-resonant frequency of the reflector on a home made 20 meter yagi. It seems obvious the best way would probably be to open it up at the center and make it into a split
On 4/21/20 6:02 PM, Tom Hellem wrote: I would like to measure the self-resonant frequency of the reflector on a home made 20 meter yagi. It seems obvious the best way would probably be to open it up
Author: Edward Mccann via TowerTalk <towertalk@contesting.com>
Date: Tue, 21 Apr 2020 19:00:33 -0700
Back in the day, Id take a couple turns around the reflector and couple it loosely to a grid dip meter. Cant imagine a few turns around the center of your reflector and hitting time delay on your ana
I new there was a reason to keep my old Millen grid dip meter ! Bob K6UJ _______________________________________________ _______________________________________________ TowerTalk mailing list TowerTa
Bob K6UJ MFJ actually sells coils that hook on the 269 analyzer. They do in fact work, but I think you can do as well with a connector and a single wire loop. a cliplead works. ______________________
I tried the MFJ coils years ago and could never get them to work with the 259 or 269. The funny thing was that after I sent them back, the people at MFJ couldnt get them to work either (after having
For anyone who doesn't have an analyzer and may have missed some of the earlier posts here about the NanoVNA, it is an amazing vector network analyzer for less than $50. There are people who have c
calibration units. There are lots of inferior copies, though, so do a bit of research to find out which ones are the real deal. They can be found on both eBay and Amazon. Dave AB7E So how are we
It has been a while since I kept up to date on it, but this link shows what I believe to be the safest bet to get the right version of the model I was referring to. Amazon also has several offerings
Author: Ron W8RJL via TowerTalk <towertalk@contesting.com>
Date: Tue, 21 Apr 2020 23:34:35 -0700
Tom, Remember to get an accurate measure of resonant frequency the element will need to be at a height above ground where used. If you measure it at stepladder height it will be lower in freq than wh
NanoVNA about and links: https://nanovna.com/ 73, Maximo <http://foro.ea1ddo.es/> It has been a while since I kept up to date on it, but this link shows what I believe to be the safest bet to get the
Tom, The proximity of the element to ground will shift the resonance, so you'll need to raise the element you're testing high enough above the ground that this detuning is no longer a significant sou
Hi Tom, I don't think you are taking the right approach. I don't think you can just "tune" one element of a Yagi antenna. You need to measure all the element sections and placements including the ele
The proximity of the element to ground will shift the resonance, so you'll need to raise the element you're testing high enough above the ground that this detuning is no longer a significant source o
Actually checking the single element resonance is a good way to check it against a model, especially if it has non-insulated boom clamps that are difficult to model. If the element has linear loading
I got a chuckle out of Jim's comment. My two A4S trapped tribanders for field day NEVER went together correctly the first try - one tuned for CW the other SSB. Fortunately, the Will-Burt pneumatic ma
Good luck on getting the files. They won't give you theiir Eznec files. Bob K6UJ _______________________________________________ _______________________________________________ TowerTalk mailing list
Good point. Modeling Yagis and optimizing with Auto-EZ is instructive in how much one change changes a lot else. Watching the automatic optimizer try to find the several dimensions of target values s
On 4/22/20 7:28 AM, john@kk9a.com wrote: Actually checking the single element resonance is a good way to check it against a model, especially if it has non-insulated boom clamps that are difficult to
Grant KZ1W W6VIO (JPLARC) field day more than a decade ago, and someone has the C3 all bundled together, with no instructions, and we're trying to figure out which element goes into which hole. Someo