Timeline for Double power-handling ability of RF amplifier output transformer
Current License: CC BY-SA 4.0
11 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Oct 16 at 14:29 | answer | added | Ryuji AB1WX | timeline score: 0 | |
| Jun 15, 2019 at 12:01 | history | tweeted | twitter.com/StackHam/status/1139865399217065985 | ||
| May 26, 2019 at 19:02 | comment | added | tomnexus | @brianK1L1. The way I think about these simple choke-and-add 4:1 transformers is that the flux serves only to generate inductance, and with the right material and enough turns, it can be very small. Also, that means very little current flowing the "wrong way" through the balun. So a virtuous cycle: more turns = more L, more L = less current, less current = less flux & heating. But perhaps this is something for a separate question, quite a hot topic among hams. | |
| May 26, 2019 at 18:18 | comment | added | Brian K1LI | @tomnexus actually, there is no flux cancellation in the output transformer of this design. The windings must be on separate core sections, whether the cores are physically distinct or are separate parts of a binocular core. The details appear in Granberg's AN-749 from Motorola. | |
| May 26, 2019 at 18:16 | comment | added | Brian K1LI | @tomnexus thanks for suggesting paralleled 50 ohm cables; that may be the final solution. | |
| May 25, 2019 at 14:07 | comment | added | tomnexus | And as the cores should carry no flux, there should be no temperature rise. In "Transmission line transformers" Jerry Sevick says if the core warms up when running full legal limit power, something is wrong. | |
| May 25, 2019 at 14:05 | comment | added | tomnexus | If it helps, 25 Ohm coax can be made from two parallel 50 Ohm cables, Sucoform141 or RG316 come to mind. | |
| May 24, 2019 at 2:05 | answer | added | Brian K1LI | timeline score: 3 | |
| May 22, 2019 at 14:51 | history | edited | Brian K1LI | CC BY-SA 4.0 |
added 267 characters in body
|
| May 21, 2019 at 22:17 | history | edited | Kevin Reid AG6YO♦ |
edited tags
|
|
| May 21, 2019 at 21:12 | history | asked | Brian K1LI | CC BY-SA 4.0 |