Re: How do I best operate a 4S-Tuner with a Doublet antenna ?


Bob KM6BMX
 

Hi all,

  Thanks for the replies.

  Frank, you mentioned a 4:1 balun. If I am connecting the 2-wire feedline directly to the tuner binding posts, how do I make / find a "bal-bal"? Or, are you suggesting that I use an actual 4:1 balun (2-wire feedline on one side, coax connector on the other side, and multiple turns of coax in between) and hook that to the coax antenna connector on the tuner?

  If I understand correctly, at 40m the Doublet will present roughly 50 ohms to the tuner. Since I can dial out most of the inductance and capacitance with the 3 knobs, I should be able to match with low SWR fairly quickly. 

  At harmonic shorter bands (20m, 15m, 10m), the Doublet will likely present with a higher impedance. Then, I can dial in increasing amounts of inductance and capacitance to match the antenna to the transceiver operating at the higher frequencies.

  I think that the tuner will really shine with some of other HF bands (30m, 17m, 12m). At those frequencies,  the Doublet will truly present as a "random wire".

  As you all say, I will know when I try it. Now that I have a feasible and highly portable antenna and tuner, I need to find a small HF transceiver to actually operate. Perhaps I can bring it to a Field Day or other operating event somewhere in central AZ and ask if I can try it with one of their rigs. 

  For my own rig, I am waiting until Hans Summer releases his QSX multi-mode all-HF band QRP transceiver. I Hopefully, his QRP Labs ( http://www.qrp-labs.com ) will make those available sometime this summer of 2019. 

  I am not yet CW capable and won't have time to learn Morse code anytime soon. Thus, I need a rig that supports SSB and maybe even some of the digital modes ( RTTY, PSK31, Olivia, FT-x, etc.)

Cheers & 73,
Bob KM6BMX
--  central AZ

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