W8WWV - AL-1200 Amplifier

Greg Ordy

AL-1200 Amplifier

My current linear amplifier is the Ameritron AL-1200, which replaced an Ameritron AL-811H. The amplifier uses the rugged 3CX1200 tube and features instant-on operation. My 756Pro puts out about 113 watts maximum. This drive level works well with the amplifier, which has a maximum input rating of 120 watts. I can easily drive the amplifier to the full legal power level, and I do not need to use the ALC feedback control.

If I have a gripe about this amplifier, and this was also true in my AL-811H, it is that they burn out meter bulbs all too quickly. Three of the four bulbs in the two meters burned out within a year of use. Since the amplifier cabinet top is held on with many screws, it is a pain to change the bulbs. Next time I go in there, I will switch to some other bulb setup in an effort to extend the life. [At the 1999 Dayton Hamvention, I mentioned the burned out bulbs to one of the folks at the Ameritron booth. They gave my four replacement bulbs, and when I replaced them, I added a 10 ohm resistor in the common supply line. The bulbs are a little dimmer, but so far are working without fail.]

Sooner or later I will install the internal QSK option, not to run CW QSK, but to quiet down the amp. Since I normally use headphones, the relay sounds are not really an issue, but the amplifier relay is truly the loudest sound I have to deal with. I did lower the fan speed one setting, according to the instruction manual. Since I do not run heavy RTTY, or other continuous duty modes, the air flow is not an issue, and the lower speed is a little quieter.

I did end up modifying my AL-1200 with the EBS-1 electronic bias system, and the updated relay board. These mods are shown on another page.

Back to my Station Tour Page

Back to my Amateur Radio Page

Last update: Monday, July 12, 1999 06:33 PM
Back to my Home Page