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Mick,

An end-fed antenna at it's design frequency (where it is a 1/2 wave say at 7 MHz and thus about 66 feet long) will have a very high impedance at the feed point (one end).? You typically can't just hook it to your antenna jack, and expect to get any power into it.? The MFJ-1984 has a so-called matching transformer (more about that later).

Various end fed feed arrangements are typically used, including 9:1 (or higher) transformers at the feed point.? That may help get the typically 1-2 thousand ohm impedance down to 100-200 ohms or so, which can get it in range of most "antenna tuners".? Also adding a counter-poise ("ground" line) there, to help stop RF from coming back down the outside of the coax shield, which can raise havoc with your rig.? Such a setup almost certainly will require a matching network ("antenna tuner") to match whatever impedance you are seeing from the antenna/transformer arrangement to your coax/transmitter.

End-feds are popular with the QRP crowd, especially for portable operations, because you only need to have a single support (nearby tree) to throw the far end up into.? But care must be exercised in feeding such an antenna, because on the design frequency (and even harmonics) it will be far from the typical 50 ohm output of modern solid-state transmitters.

Now, the MFJ-1984 is making some pretty wild claims for how well their end-fed antenna matches on practically all bands 40-10M WITHOUT A TUNER (WTF?)

I call snake oil.? If it really does show a low SWR across all those bands, it likely has a 50 ohm or similar resistor in the housing across the feedline.? This will of course, give you a nice low SWR everyplace, but it will also dissipate

most of your signal in that resistor, rather than radiating over the air.? There was an infamous shortened dipole that had a center insulator that was potted and shielded, making it difficult to see what was inside, even with X-rays.? Eventually, they were found out that the system had a big 50 ohm resistor in the center insulator housing, and thus, any band looked good, but it radiated very poorly.

You may be able to hear well, in particular on 40M, because the signals on that band are pretty loud, and you can hear OK there with a severely compromised antenna.? But, it will be very frustrating, because most stations will not be able to hear you.? Compound that with running under 10W, and you will be very frustrated, indeed.

Please start with a simple resonant (cut to frequency for that band) dipole antenna, center fed with 50 ohm coax.? You can use a 1:1 CURRENT balun at the feed point, if you want to stop antenna currents from coming back down the shield of the coax, but at the moment, that might considered an unnecessary complication.? Get it up in the air at least 30 feet or so, and try that on your setup.

A simple resonant dipole is VERY?efficient, and say if you do this for 40M, you will be pleased with getting out and making contacts (especially on CW for QRP) out to several hundred miles.? At only 30 feet, it won't be a DX champ, because the angle of radiation will be somewhat high, but it will fine for closer in work.

Hope that helps,

73,

-- Dave, N8SBE