Remote Flex-6600 + LDG RT-100 auto-tuner + Palomar Engineers BAS-71 w/9:1 UNUN

W4AFK Bruno

Our remote Flex-6600 has a built-in tuner but our antenna sometimes exhibits high VSWR. Although the FLEX' internal tuner says that the antenna is "tuned", we are concerned as in certain spots it starts at way over 5:1VSWR, while the built-in tuner is not supposed to be able to handle that … but it is.

Here is what we want to use:

Flex-6600 (internal tuner off) —> DC injector (to power the tuner) —> coax to the tuner —> LDG RT-100 auto tuner at the antenna connection point —> Tuner output to the Palomar Engineers BAS-71 antenna input, which has an internal 9:1 UNUN —> antenna wire & coax counterpoise.

The RT-100 auto-tunes on RF and memorizes most settings. There is a remote reset which we will control via on of the relays on an MHCOZY controller. I use a RT-100 at home with an IC-7300 and I only had to use the reset button when I changed antennas

Has anyone used a similar configuration? More specifically using an external auto-tuner like the RT-100? Any caveats, suggestions?

KD0RC

Hi Bruno, the ATU in the Flex is conservatively rated for a 3:1 mis-match. Any given amount of resistive or reactive mis-match over that will often work just fine. The ATU in the Flex at my club station tunes an end-fed antenna on bands it was never designed to operate on.

I have not used the setup that you describe with the LDG tuner.