Going discreet with a Random Wire Antenna and 9:1 unun.

You live in a place where there are neighbours. You have space available to place some kit, but not that much. Even if you decided to use that space, you wouldn't want your neighbours to imagine what all that stuff is about. If your neighbours found out chances are that one day you would end up having a discussion with one of them, not because you disturb TVs and they hear you talking in their toaster, but because they don't like what they don't know.

If all of the above sounds somewhat familiar, welcome to the SOC - the Stealth Operator's Club. We are people who, for one reason or another, have to go discreet - or even stealthy.

An ideal choice is the magnetic LW unun. With this simple piece of equipment you can use 20m of antenna wire across all HF bands using the inbuilt ATU of your TX/RX.

My effort for an end fed long wire antenna using alternative components. End fed LW antenna most convenient but often requires its high impedance, typically 450 Ohm, to be matched to common 50 Ohm TX/RX. Maintaining the trifilar winding spacing helps to minimise common mode currents IMHO. With the use of an antenna tuning unit this project works well on all HF 160 to 10 metres TX amateur radio bands. Also likely useful on its own for SWL broadcast bands RX. If you require to connect an earth or counterpoise use the chocolate block where the RG58C/U terminates or a coupler on the coax PL259 with shield/earth terminal. YMMV. As shown not suitable for long term external use.

Caution: It is possible to exceed the power rating of a core and the performance of the UNUN may be degraded during high SWR causing heating of the core. If the core is over heated its magnetic properties will most likely change and your UNUN will not work efficiently and may even damage your radio or ATU. The highest power I've used so far is 15 Watts.

Source: Phil VK5SRP, John M0UKD & M0ZZM. Home END OF FILE