[excerpted from the FRC Newsletter August 1999]

As one who typically operates single-op assisted in the major contests, I'm always looking at ways to jump on those packet spots more quickly, and get in and out of the "packet pileups" before they get too big. Hitting Alt-F4, while running CT or Writelog takes the transceiver where it belongs. Antenna switching is handled by Top Ten Devices boxes. And then there's the amplifier... I've used a variety over the years: SB-220, Alpha 77, and Alpha 78 (bandpass tuning was a step in the right direction, but still too slow). For several years I considered getting an Alpha 87A, but I heard too many stories about it faulting out when the match wasn't perfect. While at N3RS last year for one of the contests, I saw an antenna tuner in their 20m stack line, just so the 87A would operate without kicking out. That clinched it - no 87A for me. So now what?

One day while Web surfing, I came across a site in Europe selling an amp called an Acom 2000A. It looked like quite an amp from the specs - full power using 2 Svetlana 4CX800A tubes, autotune(!) accepting up to 3:1 SWR (!!), and very high tech (more later). So how come I never heard of it? After asking around, I found a few things: it was pretty new, there were none in the US, and it was made in Bulgaria by the same company that made the Alpha 91B. So who had one? ON4UN had an early prototype. PY5EG, 4X1AD, and GW3YDX each had one. I e-mailed each of these guys with lots of questions, and they all answered with nothing but praise for it (isn't the Internet great?!) including "the best amp I ever owned." To make a long story short, I bought one.

The amp itself is a black box with only an on/off switch. All metering and controls are on the RCU (Remote Control Unit), which is a 7x5x1 inch box with LED bar power (fwd and refl) meters, several status LEDs, an alphanumeric LCD display, and a bunch of membrane-buttons to control the menu functions. The RCU comes on a 9 foot cable, so the amp (all 80 pounds of it) can be placed off the operating desk, out of the way. Very slick!

Setup and operation is a breeze. If you're the type that doesn't like reading manuals, which is very well written, considering it originated in Bulgaria, just turn the amp on (at which time you will hear TEST in CW), watch the 2 1/2 minute warm-up countdown, and start operating. The amp senses your operating frequency with the first CW dit (a single dit at up to 40 WPM, per specs), or voice syllable, and autotunes to factory default settings. The bands from 160-10m are broken down into segments (as small as 25 KHz on 160 and as large as 300 Khz on 10m). Each band segment has a factory default tuning setting, plus 10 user-customizable settings per frequency segment. This allows you to select more than one tune setting per segment, for use with alternate antennas, partial stacks, etc. where the load differs from your primary antenna. It's completely hands-off operation! However, you'll probably want to customize the tuning for your antennas. This is done via an auto-tune menu. You select the antenna number. Choose auto-tune, press the ENTER button twice, and the LCD display prompts with "Apply drive 10-20 W," with a small bar graph to help you adjust the exciter drive. The amp then autotunes for that segment (and antenna selection) in about 2 seconds. Do this for each frequency segment you operate and you're set for life, or until you install new antennas. It is now stored in memory, and is recalled in less than 1/2 second with that single dit at 40 WPM. Should you ever want to manually tune (though I can't imagine why), it can be done via the manual tune submenu. The measure submenu allows you to monitor 2 of 20 amplifier parameters at the same time, such as exhaust airflow temperature from each tube, filament current, power gain, line voltage, last frequency used, and more, plus all the usual things. But, there's really no need to monitor anything!

These guys have thought of everything. For example, line voltages can be set on the transformer for 100, 120, 200, 220, and 240 VAC. Not fine enough control for you? Via a submenu on the RCU you can set it for "high" or "low" with respect to the transformer tap for additional fine tuning. Personally, mine is set for high, as my line voltage runs 252V (yes, I've talked to PECO about it). A HELP submenu contains info such as software revision number, tube serial numbers, and actual operating time in hours, plus various tips. There is an INFO submenu selection. This transmits remote diagnostics over the telephone via audio Baudot RTTY generated through the RCU. Diagnostics are also available via an RS-232 port on the amp. Here's one for the esoteric department: You like the amp so much you own more than one. How does remote control software tell the amps apart? Each one can have a unique network ID! You don't want your son or XYL using the amp. It can be password protected via the RCU. Finished operating? Turn the amp off and it sends a CW "AR" to you.

You probably can tell I like this amp. I'm just waiting for the contest season so I can be in and out of the packet pileups before you guys get there! BTW, the amp is now sold in the US by Acom International in MA. You can find their Web page with additional info at http://www.hfpower.com/.