The Alpha 8410 is a twin-tetrode, 1.5 kW, manual-tune, 100% duty-cycle, linear HF amplifier.  The amp now runs two 4CX1500B tetrodes in parallel in AB1 class (no grid current).  When launched in 2009 the 8410 shipped with 4CX1000A tetrodes.  The 4CX1000As were replaced in 2014 with 4CX1500Bs.

 

I liked the idea of an over-engineered amp - one you could run full tilt with RTTY and not worry about backing off the power or limiting the transmit time.  That isn't at all needed for my operating habits but that should translate into greater reliability and tube longevity than an amp operating closer to it's limits.

 

I wasn't aware when I started shopping for a tube amp that most don't have any means of monitoring or control via a PC.  The 8410 has a USB port that allows you to use a terminal emulator to monitor telemetry from the amp.  This is one of the reasons I chose the 8410.  On the PC side you install an FTDI chipset driver that makes the USB connection appear as a virtual serial port.  Once I saw what data I could get back in very terse comma-delimited strings I thought this just begged for a graphical front-end that would interpret and display the data.  And so began my software development project.

 

The Alpha 8410-8406 Monitor software was my attempt to see what was going on under the hood beyond what was displayed on the front panel.  With a software interface all parameters can be displayed simultaneously, peaks persisted, and other data not sent could be calculated.  Plus, there are two different TX states and the monitor can separate those and only display what's interesting.  The monitor software eliminates the tedium of manipulating the telemetry data in Excel or similar software.

 

From my experience the 8410 is an awesome amplifier.  Besides the no-limit 100% duty-cycle, it has comprehensive fault handling so it's difficult to damage anything.  If you're like me in that you have to open everything up and measure all the important variables, the 8410 is a dream come true (save for the 20 cover screws).  It has 56 test points exposed on the five PCBs - all little eyelets on stand-offs waiting for oscilloscope probes and DMM mini-grabber leads.

 

Dan

AE9K