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Purchase a new Alpha Amplifier between now and August 31, 2012, add $250 and get your choice of a 4510 or 4520 wattmeter!
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Jeff, K1NSS, is at it again. He's updated one of our favorite cartoons and it's posted on the front page of the website. Check it out at www.alphaamplifiers.com. Ruff.
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"This was the first time I ran VHF with a full gallon. All I can say is WOW, what a difference! Now if I can hear them, I can work them. This is a fantastic improvement. Of course hearing "N9LB - nice signal" always feels good too. I received more of these kinds of comments this weekend (CQWW VHF Contest) than I have in the entire VHF operating portion of my Ham Radio Career" - Lloyd, N9LB
No kidding - six is an amazing band. If you've not tried it, get a beam and give it a shot. One of the fascinating things about 6m is the sheer number and variety of propagation modes. This is due to 6m being located at the crossroads between HF and VHF. It is the lowest frequency band at which moonbounce is commonly done; and it is normally the highest band which sees any significant F-layer propagation near sunspot maximum. There is also summer sporadic E (Es) propagation, in which signals bounce off "clouds" of ionization that appear, move around and disappear, sometimes surprisingly quickly.
This can be extended to multi-hop Es where there are clouds situated such that two or more hops can be achieved to give extended range. When this happens, the two-hop signals are almost always weaker than the one hop. On much rarer occasions, you hear three or four hops into the Caribbean or other islands.
These are weaker still, and it really helps to have a good antenna and as much transmitter power as possible to work over these paths.
Our 8406 Amplifier is perfect for these openings. Tune to 50.125 and listen to the activity.
And, of course, give us a call and order one of our full legal power 6 meter amps and try something completely different! |
Glenn's hard at work
When he's not answering emails, or working on new amplifiers, Glenn has been spending time updating the list of available legacy parts that are displayed on our website.
We're standardizing on the format and adding information about which legacy amplifiers use each part, as well as adding images of the parts.
For examples, if you're searching for a vacuum relay, simply type relay into the search box on our website and you will get a list of all of the relays we have. Likewise for diodes, resistors, capacitors, fuses etc.
Let us know if there are parts you don't see listed so that we can add them for you.
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We have a new Dummy Load!
Introducing the A2000
$795
Introductory Price
Preorders are being accepted. As with the 4040, until we start shipping, there is no deposit necessary!
20,000 Watts for 10 seconds! - pretty impressed? Well, how about 2,000 watts until the cows come home?
Not much electronics. Just some heavy duty, air cooled railroad resistors and a matching network in a box with two heavy duty fans.
Simple Design that should last a lifetime.
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Product Availability?
IN STOCK AGAIN!
9500 - in stock
8410 - in stock
8406 - in stock
Specific product availability is listed on the front page of the website, as is turnaround times for our repair department.
And, as always, the most up to date information on the happenings at the company are listed there too. Check it out at:
The Alpha Website
Thanks for being so committed to a great brand, a hard working group of people, and our great hobby.
Call us if we can help you:
303-473-9232
The folks at Alpha:
Steve, WA2NFR
Michael, AA6DY
Glenn, AEØQ
Brad, KØHM
Carey, KXØR
Molly, WØMOM
Gordon, WØRUN
Kathy, KB2HDT
Tom, W2CO
Petar
Pam
Patricia
Carol
Mary
Mike Adell
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THE TRADE-IN TRADE-UP PROGRAM IS ENDING JULY 31st
We're giving big credits in trade for your used amplifier
DETAILS HERE
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Letter from the President, Steve Farkas, WA2NFR
"So, what do you want to work on today?" says Steve to an exhausted group called the Tuna Group (ha, get it?). "Well, let's see. How about the Alpha 4040 tuner? - it's been six hours since we touched that thing and there are hundreds of people waiting for theirs."
We're making great progress. Michael just wrote an update to the status on the Yahoo 4040 Group:
We just won't ship a single tuner with a hardware flaw we know of (and we ALL want to ship it as soon as possible). We just never want to see one of these back in our shop after we ship it to you.
Software updates? - they're done over the internet, or in the worst case we can send you the code on a memory card. But hardware? Bad news. You don't want to ship it back, and we don't want you to ship it back. So hardware (whether mechanical or electronics) has to be rock solid - and that's at the full rated output - 4,000 watts. We've spent so much time making sure the components are built to handle the power, they just have to be reliable, period.
The main problem still putting up a fight? The Coupler board. We've almost got it, but it was clearly the most demanding of our design tasks and took the most time on the bench to take care of a myriad of problems since Rev 1. Sent it out for a board spin and we'll be staring at (hopefully) our last revision of that critical board. Basically it contains the RF Coupler, two buffer amps (forward and reflected). The forward power goes to a 4:1 mux, while the reflected power goes to an adjustable phase shifter and then to the input of another 4:1 mux. Output of both muxes go to an AD8302 RF Gain and Phase Detector and then to a four channel A/D connected to an I2C bus. Also on board is a transformer coupled AGC circuit and a small PIC that's used for a frequency counter, which can be turned on and off at will.
The Tuner gets frequency information from three sources, and figures out which one to use: RS232, CIV, and from a PIC microprocessor running code to count frequency.
Now software. Our time is really being spent on the routine we call TunerD - which is the core of the application that operates the tuner. Things are looking good. We're very happy about the state of TunerD, it gets better every day and we hope you'll appreciate the ease of use. Basically, you configure it, turn it on, and leave it in auto mode. But you can mess with all the settings manually if you'd like.
We've received HUNDREDS of orders and are really excited to build and ship these as soon as possible. It's good for our customers, and it's good for us. But, we just won't ship anything before we have the meanest, most aggressive testers bang at the completed tuner and we fix the bugs they find. They have nothing to bang at yet, but they will soon. We've built test jigs for the Vacuum Caps, the stepper motors, and the inductor and run them night and day until they fail. Then we fix the failure, and run them some more.
Thanks for hanging in there - it won't be much longer. We'll get this done and we hope you'll appreciate the quality and commitment the Tuna team has built into our flagship tuner.
We are working hard every day. There are 10 people working on the tuner. The good news? The tuner is so cool, and getting cooler every (every) day.
One other thing to speak about: We're getting amps back that have been thoroughly abused. Over driven, blown tubes, and smoked parts. There's no reason to drive the amp so hard that parts fail. We design these amps to take a beating, but what we've seen lately is, well, not so good. I asked Brad to write an article which is down a couple of blocks in this newsletter. The amps keep a log of overdriving events called an abuse log. If you send an amp back for repair that has been overdriven and there are damaged parts or a blown tube, it will NOT be covered under warranty. It just makes no sense for us to pay for a $900 tube because it was driven with 150 watts - way, way more than is necessary for these amps to put out legal limit plus some.
Over the last couple years, I've met some of the nicest hams. It's a wonderful hobby, isn't it?
Steve, WA2NFR
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Letter from the Vice President of Sales, Molly Hardman, WØMOM
Friedrichshafen, Hamfests in Huntsville, and a word about the The Trade-in, Trade-up program ending July 31st.
Often over the summer things often quiet down at the Alpha Amplifier factory as our customers spend more time outdoors and travel - this summer started out that way, but as things have heated up (literally), it seems that more and more of you are staying indoors and closer to the air-conditioning - so keep that up as we love hearing from you! That is certainly true of our tuner development team as you will read elsewhere in this newsletter, but for your intrepid sales team, we will still venture out!
We're announcing the LAST CALL for our very successful trade-in-trade-up program. JULY 31st we will be ending the program. Over the past few months we've offered special trade-in deals not only for Alpha amplifier trades, but we've also taken in plenty of Ameritrons, a Collins amp, Commanders, Ten-Tec, Amps Supply, a Dentron Clipperton - you name it!
Last month saw Alpha at the show in Friedrichshafen, Germany for the first time in many years - it was great fun to meet so many Alpha customers who have only been email addresses up until now. I was also surprised to see a lot of US hams at the show - I think one could work an "eyeball-DXCC" at this show! We ran an amplifier each day into a dummy load on 220 V, 50 Hz and collected entries for a drawing for an Alpha 4520 wattmeter. This meter was won by DL1GLO - our partners at WiMo are sending the meter on to Sigi Lodko - congratulations! For the record, the meter at Dayton was won by Dave, WO2X, a 9500 owner and beta tester.
We are looking forward to attending the HamFest in Huntsville, AL, August 18th and 19th - Gordon and I hope to see many of you there. We will be running an amplifier in our booth each day and we will also have our new dummy load and tuner on show, so please stop by to say hello and enter a drawing to win an Alpha wattmeter for your shack. We also plan on taking some of our trade-in amplifiers to Huntsville, so if you are in the market for a certified pre-owned Alpha Amplifier, please let me know.
With the success of the trade-in program, those of you looking for a certified pre-owned amplifier need look no further than the HRO website, where you will find a great selection from the first Alpha 374 amplifier ever built and shipped by ETO to late model 87A amplifiers. Each amplifier listed by HRO carries a warranty on the amp and the tubes and ships directly from our Alpha factory.
Remember we have new amplifiers in stock and we continue to offer our 502525 payment plan that allows you to spread your amplifier purchase over 60 days. Please check our website or call me at the office for all of the details - and especially, STAY COOL!
73 de Molly, WØMOM
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Brad's back and he's got some words about power. 
Power is what we're all about at Alpha Amplifiers, it's what we think, breathe, and eat just about every day of our lives. I've not written for the newsletter for a long time, but I felt speaking about power was an important topic. Here's a frank article on overdriving our amps. I've seen thousands of amplifiers during my career and want to share what too much drive power can do to that beautiful amp. And, for absolutely no reason. The result is almost imperceptible to the ham on the far end, but it makes a huge difference to the longevity of the amp you're using.
Over the last ten years, I've spoken to a lot of hams. Many ask "how much power will the 9500 put out?". My answer: 1500 watts - the legal limit. There's some 'headroom' built into the amp. Drive it harder and it will put out more than 1500 watts, but it's not the best way to operate our (or any other) Linear Amplifier.
Let me explain:
The 9500 was designed to be a 1500 watt, key down all day long, linear amplifier. We designed the tank circuit to operate at the point where we get the best efficiency and linearity. Wasting power in heat, or building a Linear Amplifier that's not Linear doesn't make sense. But, what makes an Alpha an Alpha is the "Headroom" we build into these amps. Whether that's the power supply, the tube we choose, or any other component or subsystem in the amp - we design and build it to take some abuse. But, the operative word is 'some'. The 9500 is designed to produce linear power up to about 2,000 watts as long as the mains are stiff enough to supply sufficient input voltage and input current. This is why we ask you have a nice stiff 220 circuit in your shack. The amplifier is designed to deliver legal power with as little as 40 watts input (depending on band), but never needs over about 80 watts of drive to do the job.
Now the bad news. Sometimes the amps are driven so hard that parts fail and the amp has to be returned to the factory for repair. I've seen enough of these to know when an amp has been merely worked hard for an extended period of time (which is perfectly ok), and when it has been severely over-driven. I can tell the difference instantly because I've been doing this for a long time, however, the amp also keeps a non-volatile log of all of the 9500s excess power events. When I suspect this is the case, I log in to the amp and dump the logs.
The usual complaint: "My $8,000 amplifier won't put any power out. It was working fine, and now it just doesn't work at all".
Now, there's two problems: 1. There's a really upset FELLOW HAM that is unhappy about the unreliability of his Alpha, and 2. there's a good chance that he's destroyed a $900 tube AND voided the warranty* (see steve's note above).
The 9500 was designed to take a beating, but there's no reason to drive these amps so hard. The log records excess power events (over 125 watts of drive) and stores them non volatile memory. Think about it - the limit for a log event is set to 50% more than it should EVER take to drive the amplifier to 30% over legal limit.
At 125 watts of drive, the 9500 doesn't even operate in the linear region any longer, the output signal's bandwidth increases, it has more harmonic content, and the worst of it - the ham on the other side of the conversation CAN NOT TELL THE DIFFERENCE. It takes 3,000 watts to move the ham on the far end's meter a HALF of a single S unit! The first 1500 watts - a big difference - the second 1500 watts - not so much difference.
The phrase "I can't drive 55" (meaning it's not in my nature to stick to the speed limit) is nice on the highway because it seems no one can drive just 55, but in the world of RF power, the 400 or 500 watts makes just a little bit of difference (and people feel it's helpful to have a bit more power). When I hear of a customer driving and tweeking our amps to put out that extra few watts, I cringe. It's just not borne out in the math.
Granted the amp will do over 1500 but when we designed it we wanted something that would sit on the desk and hum all day at 1500.
If you need the bigger signal than what 1500 watts will produce for you, then turn your attention to the sky. A bigger antenna gets you better RX and TX so it is a win-win solution... Not to mention not aggravating others with an over driven, distorted, non-linear transmit signal.
Our ham community is one I cherish and have spent much of my life enjoying. It's a great club that I'm proud to be a member of. For me to write this was a big deal. We sell amps - and we sell a lot of them. We sell the best amps in the world - there's no doubt about it. The tag line is our badge - Ask any ham who owns an Alpha what they think of the product. We don't have to puff our chest and tell you how great they are - our customers do that for us!
My conclusion is simple: Beat the amp to death and miss that rare one because it's in for repair - and lose the warranty or use it within reason and enjoy it for a lifetime.
73's Brad
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Notes from Kathy Foster-Patton, Director of Operations, KB2HDT
Meet Petar - a technician at RF Concepts with an extraordinary background.
This article will spotlight one of our technicians who the customer base has never spoken with on the phone. I say this with confidence because his English language skills are not sufficient for technical phone support. Of course, you don't need to speak English to read a schematic or trouble-shoot an amplifier, and boy does he do a great job at that.
Before coming the the United States in 2008, Petar worked at a Serbian National Broadcast station, operating a 20,000 watt transmitter that used a pair of tubes - a 4CX1000 driving a 4CX20,000 tube with 10kV on the plate.
Petar has worked at RF Concepts for over two years. His responsibilities include inspecting, troubleshooting, and repairing most of the legacy and elderly amplifiers and getting them back into tip-top condition.
Although he has a lengthy commute every day, Petar is the person who shows up every day, just like the mailman - rain, snow, sleet, or hail. He is never ill and even brings us cake on the Serbian holidays - yes, he is a joy to work with. We are very lucky to have him here.
Thanks Petar, for a job well done.
Kathy, KB2HDT |
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Letter from Gordon Hardman, WØRUN
The Swamped Grid Tetrode Input. Hold onto your hats, folks - we're talking tetrodes.
The Alpha 8410 and 8406 use tetrode tubes, just like the older 91ß and 99. The input circuit to these tubes affects their operation, and it is worth explaining a little bit how it works. Most people know that the job of a power amplifier is to take a certain amount of power from a radio and deliver a larger version of that power to an antenna. Generally one assumes that the radio power goes into the amplifying device, where it adds to the bias of the tube, causing it to produce output power. This is the case for a cathode-driven amplifier, such as the Alpha 9500 or the 87A. In the case of grid-driven configurations, such as the 8410 and 8406, it works a little differently.
The grid in a power grid tube controls current in the tube by virtue of the voltage on the grid, not because of current flowing in the grid. In fact, designers of conventional linear amplifying tubes and those who design amplifiers that use them, generally go to some effort to try and get grid current as low as possible. If you look at the data sheet from Eimac for the 4CX1000A used in the 8410, the grid power is specified as "zero". That is not because any damage will occur if you put one milliwatt of power into the grid; but rather because the excellent linearity that this tube is capable of would be compromised by significant grid current.
Therefore, if the grid current is nearly zero, and we know that power is voltage times current, and zero times anything is zero, where does the 50 watts or so of drive power go in an 8410 or 8406? The answer is that it is intentionally dissipated as heat in a resistor in the grid circuit. At first it seems like a bad idea to simply throw away power that was generated so carefully, but there are numerous reasons why it is actually a pretty good idea.
The circuit shows the essential elements of a so-called "swamped grid" input circuit for a tetrode. The 50 ohm swamping resistor is connected between the control grid and RF ground. The DC grid bias is applied to the resistor at RF ground (the RF Bypass capacitor insures this) and the DC Block capacitor means the DC bias stays on the grid. If the tube input capacitance was zero, that would be all that is necessary for the driving radio to see 50 ohms at all frequencies. In fact there is some small capacitance from control grid to ground, and C1 and L1 are added to compensate for this, producing a low SWR over a wide frequency range. In fact, the 8410 has two compensation circuits, one optimized for the lower bands, the other for the higher ones.
So virtually 100% of the input power is delivered to the 50 ohm swamping resistor, and the RF voltage across it is added to the DC grid bias, bringing the tube to its design operating point. Very little grid current flows, and a nice highly linear amplifier results.
It would be possible to produce full power with much less driving power, if the swamping resistor was not there, and all the driving power was used to produce RF grid voltage. This is done in some amplifiers, but there is some baggage that comes with it. With such high control grid impedances, the inter-electrode capacitances and tube compartment parasitics become important in terms of amplifier stability, linearity and efficiency. These can be compensated for by neutralizing circuits, but these are tricky to set up, and must be checked every time tubes are changed or the RF tank is worked on. The 50 ohm resistor swamps all of these reactances out, and makes tube-to-tube variations much less important.
So the swamped grid approach is easy to manufacture and maintain over a long period of time; gives great linearity; makes tube replacement easy; and produces a good 50 ohm match to the driving radio.
Of course, the swamping resistors have a certain maximum power rating, and can be damaged by excessive drive. With 200 watt radios around, we occasionally see evidence of this in amplifiers that are being worked on. The damage is very characteristic and noticeable. Whether intentional or accidental, we strongly recommend that input power be limited to the maximum that produces good linearity and efficiency. That way the tubes and amplifier will last for many years with no trouble.
73, Gordon, WØRUN
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Our ongoing Promotion? We've still got a few MUGS left.
 Two cups for $5. Well, not quite five bucks. We add $3 for shipping and handling, for a total of $8.00
Who couldn't use a couple of great mugs in the shack?
To get this price, you have to order the mugs online - on our website. No call-ins, no emails, one set of two per Call Sign. Order number PRO-023.
Our Price: $5.00
List Price: $20.00
S & H:$3.00
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And, as always, you can get a FREE Alpha Baseball cap with your Call Sign embroidered on the back for posting a review on eHam.net
 Go to eham.net and post a review on any of our Amplifiers, send us a note through the "CONTACT US" tab on the front of the website and we'll send you an embroidered Baseball Cap. Thousands of people have these caps!
List Price: $15.00
Our Price: ZERO
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