Hi LF, During past days I did some more investigating about that slow antenna R change during Tx. This is making me a little crazy. I don't like RF mysteries! During a 2 minute Tx at 200W, antenna sy
Paul Would think any broken / bad contacts in the top hat would show up as a big change in resonance. Best *guess* is a problem with the ground connection connection out at the antenna. FET's shippin
Hi Paul, How do you measure your antenna current? I know, the scope. But do you measure across a small shunt resistor or do you use a current xfmr or something else? 73, Stefan Am 03.12.2018 12:49, s
Hi Stefan, I am not measuring antenna current. I am using the M0BMU ScopeMatch immediately following the LPF. The version I built has a transformer for monitoring current and capacitive divider for v
Hi Rob, I think my reply to Stefan explains what and where I am measuring... until I get a new RF ammeter at least. "Normal" X is zero, as I adjust the variometer (very slightly) at the start of each
Uh... not quite. Let's try that again! Measure voltage, measure current (I measured peak on the scope and converted to RMS) Calculate R = E/I I am assuming that works as long as X = 0. Voltage and cu
My few cents... 1- check if the antenna coil and transmitter ground share the same earth/ground connection. 2- build the simplest RF current meter (http://mirror.thelifeofkenneth.com/lib/electronics
Hi Claudio, You give some very interesting ideas !! I will try to make some of the measurements you suggest. It should be interesting to check RF current in different places. Thank you ! 73, Paul On
