I'm spending about eighty percent of my time on Alpha's new A4040 Autotuner.  It's great to get back to engineering - my true love. 

It's picture time!   

This was shot as we were assembling the first article and things look really good.  A few holes in the wrong place, but all and all, things are looking really good for shipment at the end of the quarter.  The tuner is very mechanical, and very heavy duty.  In this picture you can see the two vacuum variable caps, and the Alpha designed inductor, all direct driven by the stepper motors near the bottom of the picture.  The caps and inductors are sitting on a huge piece of Glass Epoxy board, supported by rubberized mounts so we can isolate the noisy stuff from the metal cabinet.  The gears are driving geared potentiometers that are used to sense the position of the elements.  Notice the silver plated flat stock wound on edge.  I'd tell you how this inductor is made - if I knew.  Our vendor said he'd have to... well suffice it to say, I told him I didn't want to know.  We designed our own heavy duty switches and pad cap.  You can see the three switches near the back of the unit, and the pad cap is right behind the middle capacitor.

Inside the A4040 Tuner

For the computing platform, we've chosen the Beagleboard XM running Ubuntu Linux, with a custom driver board plugged into a 7" color LCD display.  It's up and running and we're busy writing code. 

They're selling quickly.  We've already received orders for almost two hundred tuners!  If you want to get one before Dayton, you should put your order in the system. We're taking orders with no deposit necessary, so get on that list!  As soon as we start shipping, we're going to start taking deposits to get in the queue.

Over the last couple years, I've met some of the nicest hams.  It's a wonderful hobby, isn't it?   

Steve, WA2NFR     

Letter from the Vice President of Sales, Molly Hardman, WØMOM

It is a new year and with it new Alpha products are being designed. You have read and heard about our forthcoming Alpha Auto Tuner 4040 priced at $2,995. We expect to start shipping at the end of March. To date we have hundreds of  orders. If this is of interest to you, as it is for many of your friends, this is the moment to place your no deposit, no obligation order and get in line.

We took a calculated risk that many of you would love to own the very best in class wattmeter but may not be able to justify the previous prices of $995 and $945. Last month we were able to lower our price on the 4520 to $795 and 4510 to $745, due to manufacturing efficiencies. The response has been better than we had hoped. Compared to January, 2011 our orders have tripled and we will be able to ship your order in about two weeks.  Take a look at our website, read praise from our Alpha Wattmeter owners and consider placing your order today.

Here are our shipping expectations. If you place an order today you will receive the Alpha 9500 at the end of March, the Alpha 8410 in 2 weeks,the Alpha 8406 in 3 days. 4520 and 4510 Alpha Wattmeters will be shipped within 2 weeks of placing your order. Orders placed today for our newly announced 4040 Alpha Auto Tuner will ship during the 3rd quarter of 2012.

Product Updates
We have a new one-stop-shopping Downloads table on our web site where you will find firmware for new products and information on old amplifiers. 9500 and 8410 owners might want to take a look at the latest firmware updates and install the new firmware on the amplifiers. We also have a new beta version of the 9500 PC application.  Instructions for firmware  installation are on our web site or you are welcome to call anytime for assistance.

We were at Orlando, February 10th and will be at Visalia, April 21st and Dayton - of course - May 18th. Stop by to say hello. See you then and thanks for your continued support.

73 de

Mike and Molly, WØMOM   

Letter from the Vice President of Engineering,

Gordon Hardman, WØRUN 

Gain, Efficiency and Amplifier Tuning

For many years Alpha amplifiers have featured a tuning aid to help the user adjust the Tune and Load capacitors to set the amplifier for optimum performance. In earlier amplifiers that did not have a microprocessor as their controller, an analog computer produced a voltage which was related to gain. This was displayed on a bar-graph, with the design gain being in the middle of the scale. When micros were incorporated, the gain was computed digitally and also displayed on a bar graph. With the advent of the 9500 and 8410, the labeling for the scale was changed from "TUNE" to "GAIN", and the actual gain values are printed next to the bar-graph.

The manuals would always tell the users to get the "TUNE" indicator in the middle of the bar-graph at low power (at less than 20 watts various safety trips are disabled so the user can find initial settings). Then the manual generally says something along the lines of "touch up the tune and load for best efficiency at full output". Of course, there is no direct indication of efficiency, and it requires some care and understanding on the part of the operator to find "best efficiency". It is possible to change drive power, tune and load settings to get the same power output but with very different efficiencies.

With the 8406, it was realized that the micro had all the information it needed to compute efficiency, so why not display it on the front panel. After all, gain is just a proxy for correct amplifier adjustment, a holdover from the analog computer era. So 8406 amplifiers are now shipped with a front panel that does not show gain but instead has efficiency as the third switch-selectable parameter on the multimeter. This makes finding best efficiency easy- further to the right equals higher efficiency, so at your desired output power adjust drive power, tune and load to get the bar graph as far to the right as possible.

After this was incorporated, the idea of displaying waste heat came up. This is a tuning method equivalent to tuning for best efficiency except you tune for minimum waste heat. So you want the bar-graph as far to the left as possible. The scale for this is the same as the high voltage (HV) scale, but in kilowatts rather than kilovolts. So 1.0 kV on the bar graph means 1.0 kW of waste heat when that mode is enabled.

All of our current production tetrode amplifiers use the same controller and software, the type of amplifier being set by our technicians when the amplifier is "born" in the factory. This has been true since version 2.01C of the firmware was released. So they all now have the ability to show either gain, efficiency or waste heat on the third multimeter position. As of today, 8410s are shipped with gain as the displayed parameter, and 8406s with efficiency. This can be changed by setting a "configuration bit" through the USB port. This must be done carefully, as it requires the user to enter "factory mode", and it is possible to mal-adjust other parameters at the same time. Additionally, the front panel marking will say whatever the amplifier was created with. We are currently discussing whether it would be desirable to let users make this change themselves. Perhaps a small printed decal will be produced that says "Waste Heat" or "Efficiency" to place over the "Gain" marking on the front panel.

Note that even if gain is not displayed, it is still being monitored by the micro as this is one of the primary safety features of any amplifier.  A sudden drop in gain would indicate a problem either in the amplifier or with the load connected to it.

As explained in an earlier newsletter article, the efficiency of an amplifier is highest at full output power, and without adjustment, if you want to run the amplifier at lower power output, say 1kW, the tube is actually going to run hotter than at 1.5kW. With the efficiency or waste heat, the amplifier can, to some extent, be re-optimized for better efficiency and less waste heat at a lower output power.

So keep the tube cool, and your amplifier will have a long life at legal power.

73, Gordon, WØRUN