I recently upgraded to General and am trying to get my HF station working. I am experiencing some behaviors that seem non-intuitive for me, but probably make sense to you. Can you please help me understand what may be going on?
My Station: a Yaesu FT-747GX Transceiver going into an MFJ-949E tuner. My power supply is an Astron RS-50A and my microphone is a Kenwood MC-60. I'm feeding a horizontal dipole with about 50-60ft of Radio Shack's 20 gauge 300 ohm twin-lead. The dipole is a random 40ft length (the length of the peak of my roof), sitting on top of concrete roof shingles.
Concrete is a pretty good conductor. You need to elevate the wire off the roof so it's not so closely coupled to the concrete. Effectively, your wire is just about the same as laying it on the ground. See if you can get it up a couple of feet minimum. Especially the feed point. Also, it's a bit short for 40 meters. You need to add some wire to the ends and zig zag them in opposite directions down the roof edge. It'll make the antenna much easier to tune on 40 meters. Try to get each end of the antenna up to 32.5 feet long.
According to the meter on my antenna tuner, on 40m it tunes to 2:1 SWR, and on 15m it tunes to 1.3:1 (tuned using CW solid carrier on very low-power). I then switch to SSB mode, hit the PTT on my mic, start calling TEST or CQ while I turn up the transmitter's power. It begins putting out about 10watts (avg.), and the SWR stays near what it was on CW, but power won't go much beyond 20 or 40 watts when I talk.
That rig does not have a peak reading watt meter. Since it's an averaging meter that can't read the really fast voice peaks while you talk, it reads much lower than peak. Usually around 25% of your peak would be a normal reading. Cranking up the mic gain to get an average reading watt meter to read high on the scale generally leads to you not being understandable to anyone who might hear your signal.
There are many watt meters available that you can put inline after your rig that will give you a real picture of your wattage peaks while using ssb, but a good starting point would be for your average power to read about 25 watts. And getting your antenna closer to the correct length and elevated will make a huge difference in how you will be heard.