Timeline for Where are the baluns for VHF and higher? How can one be made?
Current License: CC BY-SA 4.0
5 events
| when toggle format | what | by | license | comment | |
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| Nov 28, 2022 at 3:39 | history | edited | KJ7LNW | CC BY-SA 4.0 |
Specific product details
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| Dec 9, 2020 at 18:31 | comment | added | William | This is kind of mixing some of my issues, as the line I've had the most problems with is HF, not VHF like this question is talking about. On HF, I'm using six ~1"-long snap-n #31 ferrites, but it hasn't been enough. On VHF, I think I just slapped on some random ferrites I found cheaply because the higher frequency generate impedance more easily than HF. | |
| Dec 8, 2020 at 21:47 | comment | added | KJ7LNW | How many did you use (how long)? A #61 with a 2.5mm wall that is 1" long is only 168 Ohms of impedance at 100MHz. Even at 1GHz it is only 468 Ohms, and you want at least 1kOhm, preferably more so it would need to be 2"+ of #61 at 1GHz and 7"+ at 100MHz. The lower the frequency, the more you would need. There other materials, too: We are looking at 2m on LMR400, so estimating with 100MHz specs, I can get 1.5kOhm with 5.6" of Laird 28B0735-300 and it costs < $5 at Mouser. | |
| Dec 7, 2020 at 15:09 | comment | added | William | I did this a lot and it didn't seem to help, unfortunately. I'd have to double-check the mix to be sure, but I remember picking one that was relevant at the frequencies I was using. | |
| Dec 6, 2020 at 0:50 | history | answered | KJ7LNW | CC BY-SA 4.0 |