"The group has been burning the midnight oil to get the new DreamTuner finished.  Lots has happened in the last month or so.  I'll spend a bit of time explaining the status of the project, and I'll spend a bit of time showing off what we've finished.  Let's just jump in.

We're making great progress.  Right up front, I can tell you that one sub assembly, the Coupler, has been the tall pole in the tent.  We've changed the coupler assembly from a single board that mounts on the back panel right behind the input connector, to two assemblies - one box with the magnetic components sealed inside, and two small coaxes leading to the circuit board full of components in the shielded front part of the unit.   The board in the front has all the phase shifters, multiplexers, log amp, a/d, AGC, and the frequency counter on board. Our original design just didn't deliver the performance we needed.  It would have been great to figure this out first, but you just never know how these circuits perform until you build them and integrate them with the rest of the design.

No question that the coupler has taken a big chunk of time out of our original schedule, but we feel like we've got this one wrestled to the ground and it won't hold us up any longer.  The board is out for fab now, and when it gets back, it should pretty much drop in. 

We're building the 10 beta units near the beginning of October, and we're building the first production run in November.  We've got hundreds of people waiting and we're chomping at the bit to ship the DreamTuner.      

On to the pictures.  First one is the Home page.  This graphic comes up when you power the unit, or you select 'Home' from the top bar.  Remember, it's a touch panel, so operation should be natural.  The Home page shows large thumbnails of each of the three measurement modes, along with a simplified Schematic of the tuner - operational switches and all:



During operation, each of these thumbnails will show the actual signal - Smith Chart of the Antenna Impedance, SWR plot of the antenna over the band, and a Station monitor modulation envelope. 

Touch one of the thumbnails and up pops a full screen view of the format of interest, along with three controls which can be set by tapping the left and right arrows, by direct entry via a keypad, or by using the big knob on the front and turning it to select the element you want to change:



We've shown an inside shot, but here's another.  Notice the two hefty vacuum variable capacitors, the custom edge wound inductor, the pad cap, and all the high power switching elements:



Additionally, you can see the two muffin fans aligned with the inductor.  There's a thermocouple in the box so if you're dissipating some heat, the fans will switch on (yes, they're variable speed) to cool things off.  On the left bottom you can see the front of two of the type 23 stepper motors used to drive the two capacitors.

Here's a picture of the front panel:

Last picture is the one we're most proud of.  It's got a lot of elements to it and I'd like to explain it:



Our transmitters are designed to 'look into' 50 ohms of pure resistance.  But antennas and transmission lines rarely present 50 ohms of pure resistance - and even if you hand tune your load to be 50 ohms, when you change operating frequency, the load changes.  Antennas present two components:  A resistive component that's not dependent on frequency, and a reactive component, that is dependent on frequency and can be inductive or capacitive.  This is why antennas can be defined using a 'real' value and an 'imaginary' value - a complex number, normally written as R + jX or R - jX. This complex number is easily represented on a Smith Chart, like the one above.  The Horizontal line represents the R.  Any location above the line represents the complex component of inductance, and any location below the line represents the complex component of capacitance. 

Antenna tuners are designed to transform the R + (or) - jX to 50 ohms.  This is where the similarities end.  (most) Hams don't need a 4kW tuner, but there is a reason we built one that could handle that much power. 

Take a look at the Smith Chart above.  Dead center there's a dot which for purposes of this discussion will represent 50 ohms of pure resistance.  Concentric circles around that dot represent constant SWR circles.  The first circle on the chart above is a constant SWR circle of 1.5:1.  Anywhere on that circle, you will have a transmitter to load match of 1.5:1.  The next circle out is 3.5:1, then 5:1, 10:1, and the last circle represents 20:1.

Now look at the Light orange and notice those circles get darker as you move to the left on the Smith chart.  They say that, for instance, you can use the tuner at 4kW anywhere inside the 1.5:1 SWR circle.  You can also see that as the load gets further from the 50 ohms of pure resistance, the power handling capabilities of the DreamTuner goes down, but even when you have a 20:1 match, you can still use our tuner at 1kW.

That's the power handling difference between the Alpha A4040 DreamTuner and every other tuner on the market.  They all have power ratings, and in a small SWR circle, they can probably deliver without letting smoke out.  But, there are NO other tuners on the market that can deliver performance like the DreamTuner. 

And we've still not said anything about the auto tuning capability or the graphical user interface! 

This is a wonderful piece of equipment and although it's only in the lab right now, it's just about to be released so all can appreciate it in their shack.

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

Steve, WA2NFR     

Introduction from Kathy Foster-Patton,  

KB2HDT

Meet Tom Walsh, W2CO

This month, I am putting the tech spotlight on Tom Walsh. Tom has been with RF Concepts for nearly two years now. His focus is on tuning up new 9500 amplifiers. A Colorado resident for over 30 years, he has been a ham since the age of 10. Like some of the other techs who work at RF Concepts, Tom also has a commercial license - the General Radio Telephone Operator License.

Tom goes over the 9500 amplifiers with a fine tooth comb when they come over from manufacturing and runs them through the burn-in process. He is intimately familiar with this amplifier and documents the quality problems he discovers and conveys them back to the manufacturer for correction. He is a stickler for getting the work done correctly and says he wants the amplifier to be the way he would want it if he was the customer buying it.   And he should know, because he runs a 9500 in his own shack...

Letter from the Vice President of Sales, Molly Hardman, W�MOM

Three Years - We've had a new owner for Three Years - And what a difference it's made.     

What a difference 3 years make! That's right, it's now 3 years since we sent out the first newsletter to our customers under the RF Concepts name announcing the purchase of the Alpha name and assets by Michael Seedman, AA6DY. Our goal at the time was to keep doing many of the same things as before - i.e. continue to build the best amplifiers in the world, but to build them so that we would have them on the shelf. We also had the desire to add new products and that is finally coming to fruition with the addition of the Alpha 2000 dummy load shipping this month for the first time and more particularly with the Alpha 4040 antenna tuner that will be shipping in quantity by the end of the year. For me personally, the best part of the last 3 years is that I am able to continue working on what I love best - that is, talking to customers, traveling to hamfests around the country to meet customers in person and solving technical issues. I can't wait to see what the next 3 years will bring!

Things are starting to get really busy at the factory now that we're heading into the fall - I always enjoy the first week after Labor Day as the phone suddenly rings off the hook as people come inside and get busy getting their shacks ready for the fall season. If you're in the market for a new amplifier, I recommend you call soon whilst we have amplifiers in stock.

So far this year, we've been to Orlando, Dayton, Friedrichshafen and Huntsville. In Huntsville (as we usually do) we ran a drawing for a free wattmeter and we will be shipping it to Roger, N4HZ, whose name came out of the hat first!  At the end of this month I will be traveling to W4DXCC in Knoxville and am looking forward to meeting with customers and friends there. Let me know if you have an idea of where you think Alpha should go next!

73 de Molly, W�MOM

Letter from Gordon Hardman, W�RUN  

Details, Details - it's what makes an Alpha Amplifier the best amp in the world.  Today we talk about an incredibly interesting topic: Aluminum and Chromate!  

When you install the transformer in your Alpha amplifier or tuner, you will have a chance to examine the quality of the engineering and construction on the interior of the unit. We often here comments like "beautiful" or a "like jewelry". While the shininess of a new amplifier's interior is striking, it is there mostly for good engineering reasons, and not just to look pretty.

The first thing you might notice is that all the aluminum parts are a light yellow or gold color. This is because we have all parts subjected to "chromate conversion".  Chromate conversion coating is a type of conversion coating used to passivate aluminum, zinc, cadmium, copper, silver, magnesium and tin alloys.  It is primarily used as a corrosion inhibitor, primer, decorative finish, or to retain electrical conductivity. The process is named after the chromate found in the chromic acid used in the bath.

Since shielding between one compartment and another is critical, it is important that each piece of metal that is screwed to another be in solid electrical contact with it.  Aluminum is troublesome in that respect, since it grows an oxide "skin" immediately the bare metal is exposed to the oxygen in the air. Unlike iron, where oxidation occurs very slowly, aluminum oxidizes with milliseconds, so there is no way to avoid the build-up of a layer of aluminum oxide before joining two pieces together. The oxide is tough and it is an insulator. Toothed lock washers help, by pushing through the oxide, but for the most reliable contact, it is necessary turn the outer surface conductive, hence the chromate conversion.

The other two properties of the conversion are also useful- if the amplifier is used in a sea-air environment, corrosion of the chassis will occur more slowly with the chromate conversion. It also acts as a nice primer for the powder coat paint that is applied to the outer parts of the chassis.

The other thing that you will notice is the amount of silver plated material in the tank compartment. We build the big tank inductor out of bare copper, and after the taps are soldered on, we send it out to have the whole assembly silver plated. We use silver for a number of reasons. Silver has the highest electrical and thermal conductivity of any element. Since the RF current flows only in a thin layer due to the "skin effect", the inner part of the conductor is only there for mechanical and thermal reasons- as far as the RF is concerned, it is as if we had used solid silver tubing! Other coils are wound with silver plated bus wire, and the switch contacts and other straps are also silver plated.

Silver has one other very nice property- it is almost as conductive when tarnished as when it is new and shiny. So even if your old Alpha 77 has an almost black tank coil, don't worry- this is inevitable, and it has not lost any significant performance. If you want it to look shiny again, this can be done using Tarn-X, but remember it is strictly cosmetic, and won't improve the performance at all.

73, Gordon, W�RUN   

Brad's back and he's got some MORE words about power and the wonderful line of Alpha linear amplifiers.

Boy, did I get feedback on my last article.  And, like everything, some positive and some negative, but everyone was gracious and appreciative about the information.  

One thing I wanted to clarify is that, although we do have an 'abuse log', nothing gets written to it unless the amp is really abused.  How abused?  If you drive the amplifier with over 125 watts, it counts the number of instances, not the time, and it doesn't react to spikes over 125 watts. Since you can drive the Alpha 9500 to full legal limit with 35 to 55 watts, that's really hitting it hard.  But, we understand that in the heat of battle, barefoot to QRO transitions can be hectic.  In fact, it's one of the great 'features' of using tubes in an amplifier.  They're way, way more robust than transistors.   

When I get an amp back, I usually dump out all the logs to see how the amplifier has been performing.  There's all kinds of information in the logs, and they can help us locate an issue quickly.   

You can be sure that I don't run off to write something in your file - I just use the information to bring the amp back to factory specs.  In fact, I've been reviewing logs since the early 87A was released and I've never done anything with the logs except look at them for help in locating the problem.