Showing posts from November, 2010

43′ Vertical Matching Network Debugging – con’t

  43′ Vertical Matching Network Debugging – con’t Filed in Antennas on Nov.02, 2010 I got the matching network back on the bench tonight.  I started by confirming that the Unun leads are as I expected. I hooked a 220 ohm resistor across what I thought was the high impedance side, and connected the Rx Noise Bridge across the low impedance side.  I read very close to 50 ohms with zero reactance on the low impedance side.  So the Unun is working correctly. Next, I wired the Unun back into the matching network.  Again, hooking the 220 ohm resistor across the output, I measured the input: Nearly ZERO ohms!  (This was with the relays de-energized, so the coils were out of the circuit. So I suspected either the caps between the input and the Unun, or the choke for the relay power.  I disconnected both, and temporarily hooked up only the caps on the input to the Unun.  Aha! back to very close to 50 ohms through the caps to the low side of the Unun.  That means the caps are not t