There are several sources on the Internet which length you can use for a random wire antenna (where the “random” is not really “random” 🙂 together with an 9:1 UnUn.
However most of these sources are using the US length in “foot”. Here is a table with the optimal values in “meters” (for me and for the rest of the world :-)):
| Foot | Meter |
| 29 | 8,8392 |
| 35,5 | 10,8204 |
| 41 | 12,4968 |
| 58 | 17,6784 |
| 71 | 21,6408 |
| 84 | 25,6032 |
| 107 | 32,6136 |
| 119 | 36,2712 |
| 148 | 45,1104 |
| 203 | 61,8744 |
| 347 | 105,7656 |
| 407 | 124,0536 |
| 423 | 128,9304 |
Random Wire Antenna Length