End fed 40M half wave.

[Lamewolf]

An old ham once said "tuners are for wussies." 
That said, tuners make life much more convenient.  My main antenna is one 180' long wire connected to a tuner and I can work 160M - 10M with it.  Yes, it's a low performance compromise, but for me it beats making my yard a spider's web of resonant wires.

Annnnnd....Roger!
I know some of those guys; the same ones that, according to them on air, wouldn't be caught dead owning a balun or unun of any kind either. Digging a little bit I find they have the luxury of big acres and run lots of open-wire line to so many wires and obstacles in the air it looks like Heinz Guderian defending against Brit gliders on D-Day (at this writing 69 years ago the Dakotas were taking off for the French coast with their LGOPs about to bring the rain down on the Wehrmacht).

I don't have such luxuries, I don't' like RF in the shack or getting bit, and with the small circuits available today I'll happily pack a few extra ounces to toss up one piece of wire and be versatile.
8)

In this modern world of no tune rigs, a tuner is for folks that still like to twiddle knobs like in the old days !

[gil]

Tuners are convenient and useful when you are not trying to tune an antenna that's way off... I only use end-feds, so my tuner is an end-fed matching device. It is not meant to be used with a non-resonant antenna. I use very little power as it is, I can't afford to lose any with a non resonant antenna... The tuner is also at the base of the end-fed, so that limits coax losses. Generally, I always try to avoid tuners, but sometimes if it means operating or not, of course I will use one.

Gil.

[Lamewolf]

Tuners are convenient and useful when you are not trying to tune an antenna that's way off... I only use end-feds, so my tuner is an end-fed matching device. It is not meant to be used with a non-resonant antenna. I use very little power as it is, I can't afford to lose any with a non resonant antenna... The tuner is also at the base of the end-fed, so that limits coax losses. Generally, I always try to avoid tuners, but sometimes if it means operating or not, of course I will use one.

Gil.

Oh I know all about end fed half waves - they are one of my favorite antennas for field operation and the EFWA tuners are easy to build from scratch too.  But I always have to laugh when I here someone mention that ladder line and tuners cause RF in the shack when in fact coax is much more likely to cause such problems due to common mode currents on the outside of the shield.  I call the outside of the shield in coax the "third wire".  I've used tuners and balance line fed non resonant antennas for years with no RF in the shack and never been "bit" by RF.  My main antenna is a 40 meter extended double zepp that is 178' long and center fed with 450 ohm feedline and will work 10 thru 160 meters.  Then I have an Antron 99 for 10 meters and an Eagle one vertical that will work 10 thru 40 meters via a tuner - no problems with any of them causing RF in the shack.  And by using balanced feedline, losses are pretty darn low.