I’m QRO Now!
Since establishing my station a few months ago, I had planned to add a linear. I did quite a bit of research and finally settled on the Ameritron AL-80B.
I liked the power range, 1000W SSB, a 10db gain from barefoot, while still running almost comfortably on a household 120V circuit. I liked the price, under $1400 shipped from hamradio.com. I also liked the 3-500Z based design. It seemed like a good design around a tube originally designed for this purpose. It can push the tube hard, but I believe mainly within its specs. Operator error is another thing altogether…..
The package arrived a little worn in the corners, but not abused. The inner box seemed fully intact. The unpacking process went smoothly. I opened the amp, looked wherever I could conveniently for anything loose, broken solder joints, etc. I didn’t find anything amiss. I wrote to Ameritron and received confirmation of the very complex 10/12 meter modification (yet to be done, but I will next time it’s opened). It requires cutting 10 to 15 strands of wire all twisted together and wrapped in a color coded insulated sleeve.
My dummy load didn’t arrive in time for the first night, so I admit I tuned up on the air — after finding a clear freq. Shortly I’ll have the dummy load / switch in place and will build my helper table of starting points for a few freqs in each band.
During the process, I may have cooked one antenna accessory, but that will be repaired shortly. Subsequently, I’ve had several days of increased fun on 40 meters. With my very stealth station, the power gets me within striking range of a respectable dipole at a good height. I’ve had at least a half dozen QSOs already that weren’t possible without the amp.
I’m running about 800W PEP SSB when its on. It doesn’t seem to work hard at all, not even creating a basic glow in the tubes.
So far, the experience is very positive. This seems like a solidly built, straightforward amp, with some helpful longevity / operating features (e.g., step start; peak-ish reading meters; dynamic bias; decent ALC implementation; fast warm up).
I tune with the following process:
10W carrier exciter out – max RF output on plate, then load, lather rinse repeat, rotate load clockwise a bit. I watch grid and plate current through the whole process. Once peaked and normal looking, I Increase to about 60W drive, repeat the process. I then go on the air at about 60-70% power with my 100 watt ICOM unit in SSB. The meter hovers in the 700 to 800 W area during voice peaks. Audio reports have been excellent so far. I keep the ALC set to protect the AMP, but not really compress the RF output.
Once I’ve had this a few months, I’ll post a little more.