Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net

   Home   Help Search  
Pages: Prev 1 2 3 4 5 [6] 7 8 9 Next   Go Down
  Print  
Author Topic: Ameritron ALS-1300 Unpacking / Pictures  (Read 40031 times)
AA4HA
Member

Posts: 1434




Ignore
« Reply #75 on: March 04, 2011, 02:23:18 PM »

I recently passed on the opportunity to pick up an ALS-1300 that had been back to the factory twice before. There are just too many warning signs that point to continuing problems down the road for Ameritron and designs like the ALS-1300.

Having worked in RF design, compliance engineering and electronics manufacturing QA it appears that there are a few critical steps at MFJ/ Ameritron that are not given the appropriate amount of emphasis.

There is no excuse for products rolling out the door with loose components; boards, cables, screws, etc... They need someone very experienced serving in that role who has the authority to stop the production line when a chronic problem is appearing. There may be a QA person who makes sure that the case is nice and shiny and it fits properly into the shipping box but has no idea of what is a good or bad product.

Things need to be burned in at the factory. I am not talking about vibration tables, overvoltage testing, salt spray, etc... but these rigs should be powered up for at least some amount of time and flipped through all bands and modes of operation... up to the stated duty cycle. Now if they do not list a duty cycle that is just a big red flag to me. It is amazing what will smoke, spark or let go with a BANG! During these tests. It is much cheaper to fix a problem right at that point in time than to let it get shipped out to the customer where the smoking, sparking and banging will happen.

The designs need to be conservative. You cannot push semiconductors at 100% of their datasheet specs and expect that to hold for any amount of time. As we have seen, a single component failure on the solid state finals just does not take out one transistor. If that means derating the product and calling it an ALS-1000 then let's be truthful at to what the average ham can expect for the next 5-10 years off of that piece of gear.

Things like frayed ribbon cables... looking at those photographs a few months ago I came up with a mental list of a half-dozen things that should have been done just slightly differently. Most of them would have been at a cost nearly insignificant to the manufacturer.

Buying an amp to find out that to "fix" a problem during normal operation requires you to add ferrites internally is a work-around. That problem should have been found at the factory during the design phase and incorporated into every new product.

I don't know, there are just too many warning signs. I will spend 50% more money on an equivalent amplifier if I do not have to deal with a semi-annual trip to the UPS store to ship the thing back to fix the same problem.

Ms. Tisha Hayes
Logged

Ms. Tisha Hayes, AA4HA
Lookout Mountain, Alabama
KD8MJR
Member

Posts: 2275




Ignore
« Reply #76 on: March 08, 2011, 12:35:52 PM »

If after reading this thread you go out and buy an ALS-1300 I might have some land in Florida that might interest you.  It's close to the water and is nice and Green  Grin
Logged
AG8K
Member

Posts: 33




Ignore
« Reply #77 on: March 08, 2011, 06:45:14 PM »

 Roll Eyes I suppose that means you are not interested in buying my ALS-1300 amplifier.  I was planning on using the cash from the sale to put towards an Alpha 9500. 

However my ALS-1300 has been working fine since 4 MRF-150 FETs were replaced that burned out.

Do stepper motors cost so much that cheaper tube amplifiers can't use them to provide automatic tuning like the Alpha 9500?  Stepper motors work fine also in my Palstar antenna tuner.
Logged
NG7M
Member

Posts: 9




Ignore
« Reply #78 on: March 08, 2011, 07:08:34 PM »

I haeven't posted for a long time... this thread has a life of it's own.  My ALS-1300 has been fine too since the second trip back (Ameritron picked up the shipping both times too).  By the way, I have a good friend with an ACOM 2000A.  Guess how many trips back for repairs he has had?  You guessed it... 2 times back on his dime.  So ACOM isn't immune to issues either.  $7000 doesn't buy reliability in all cases either.

As I have posted about 4 or 5 times from the start of this thread... you are not getting and Alpha or an ACOM here for $2500.00.  Just know what you are getting for the cost.  It's a lot of no tune amp for the money at the end of the day.  The problems are included too.

I love it when guys feel the need to chime in without any experience with the amp.  Trolling away with no value add.  I would suggest that you run out and get an ACOM or Alpha and then go troll the threads on those amplifiers.

NG7M
« Last Edit: March 09, 2011, 06:30:19 AM by NG7M » Logged
W8JX
Member

Posts: 5785




Ignore
« Reply #79 on: March 08, 2011, 08:29:50 PM »

$7000 doesn't buy reliability in all cases either.
NG7M

I have a Dentron QRO that i paid 400 for 17 years ago and has made no trips to shop and still will easily exceed a KW output. Point is when you are comparing prices, you can still spend less with tubes and get better reliability too as though it is dated it is very matured and proven. I would rather have a amp with zero trips to shop rather than having it shipped free a few times for repair. Ameritron needs to derate that unit some as reducing output a few hundred watts with a bias/voltage change would greatly extend its life with less than 1db of loss. I hope this is last trip to shop for you but track record is not there. One day we will all have SS amps but that day is still a long way away.

BTW if I wanted to spend 2500 on a Ameritron amp it would be a AL 82 as it is a proven tank and well built and a true legal limit amp.
« Last Edit: March 08, 2011, 08:32:13 PM by W8JX » Logged

--------------------------------------
All posted wireless using Win 8.1 RT, a Android tablet using 4G/LTE/WiFi or Sprint Note 3.
K7KB
Member

Posts: 607




Ignore
« Reply #80 on: March 10, 2011, 11:39:25 AM »

Well my ALS-1300 has been at Ameritron for 2 weeks now for repair and I haven't heard a word yet. I know it's not an unreasonable amount of time, but I'm curious of those who have had their Ameritron amplifiers repaired if they somehow acknowledge they are starting the repairs, or do did you just get a UPS notice that a large package was being shipped to your address from Starkville?

John K7KB
Logged
W5UXH
Member

Posts: 20




Ignore
« Reply #81 on: March 10, 2011, 02:43:59 PM »

My ALS-600 has been there close to two months now.  Hard to get any responses via phone or web query, but they finally acknowledged it was there and said they would get to it some day.  I'm sure they will not just ship mine back as a surprise since they will want some payment (not in warranty).

Chuck W5UXH

Well my ALS-1300 has been at Ameritron for 2 weeks now for repair and I haven't heard a word yet. I know it's not an unreasonable amount of time, but I'm curious of those who have had their Ameritron amplifiers repaired if they somehow acknowledge they are starting the repairs, or do did you just get a UPS notice that a large package was being shipped to your address from Starkville?

John K7KB
Logged
K7KB
Member

Posts: 607




Ignore
« Reply #82 on: March 10, 2011, 04:05:16 PM »

My ALS-600 has been there close to two months now.  Hard to get any responses via phone or web query, but they finally acknowledged it was there and said they would get to it some day.  I'm sure they will not just ship mine back as a surprise since they will want some payment (not in warranty).

Chuck W5UXH

Two months? Eeeks! If my 1300 is there for that long I'm NOT going to be a happy customer, that's for sure. Hope you get your amp back soon!

John K7KB
Logged
WX7G
Member

Posts: 6048




Ignore
« Reply #83 on: March 11, 2011, 06:48:48 AM »

I love it when guys feel the need to chime in without any experience with the amp.  Trolling away with no value add.  I would suggest that you run out and get an ACOM or Alpha and then go troll the threads on those amplifiers.
NG7M

I agree, many who comment here have not owned a SS amp nor have they had experience with tubes of recent manufacture. And they are not electronic engineers.

They attribute ALS-1300 failures to design defects. But as I have pointed out, and the designer of the amp has pointed out, the problems are due to workmanship. Get the workmanship under control and the ALS-1300 is a fine amp. It has good design margin.

Those who cite their long experience with a particular tube amp might replace their old reliable tubes with new tubes from China. Watch for smoke.

And those who say it takes only seconds to tune their tube amp should try a SS amp. They just might come over to the dark side (SS) after experiencing instant band changes with no tuning, low input VSWR, no heat pumping out constantly, and no drama.  
« Last Edit: March 11, 2011, 06:53:03 AM by WX7G » Logged
W8JX
Member

Posts: 5785




Ignore
« Reply #84 on: March 11, 2011, 08:30:20 AM »

Sometimes you do not have to own something to fully understand the limitations of its design. It is called reading and research and their is no shortage of bad press on those amps that i have seen in type or heard from fellow hams on air. Just because everyone else jumps off a cliff I do not have to to know it will not be pleasant. If Ameritron had dropped the hype and de-rated amp so that "rated" output was not at device maximum capacity it could have been far more reliable than it is. (It could have been a fairly solid 1000 watts amp with a few tweaks in supply voltage and bias rather than a failure prone 1300 watt amp) There are some bullet proof SS amps out there but it is not the AL1300.  Saying otherwise does not change what it is or its design. Nor does trying to "shoot" those in print that point out its limitations exonerate amp design limitations.
Logged

--------------------------------------
All posted wireless using Win 8.1 RT, a Android tablet using 4G/LTE/WiFi or Sprint Note 3.
KD8MJR
Member

Posts: 2275




Ignore
« Reply #85 on: March 11, 2011, 03:18:12 PM »

I am an Electronic Engineer for 26 years and I own a Tokyo Hy-Power SS Amp and I have owned a Swan Tube Amp and I have also rebuilt a Kenwood TL-922.
So whats your point!  It does not take an Electronic Engineer to see that if you use a Bank Of FETS that are rated at 1200 Watt Maximum and then use them in a Amp set to put out 1200 Watts that it's only a matter of time before they Fail or the PS Fails.  On top of that, that's exactly what is happening; so I just don't get your point!

  If your saying that Ameritron workmanship is Crap then that's just another reason to stay away from the Amp.  As I pointed out in an earlier thread, the Yaesu Quadra and several other Amps use the same eight FETS in the PA yet they rate their amps at 1000 Watts, so are we to believe Ameritron just figured out something that none of the others could or that they just plain wanted to use the typical MFJ standard of rating everything at it's theoretical maximum.
I am truly happy that they must be suffering a big $$ loss with this Amp, let it be a lesson to them to stop pushing and Rating everything at 100%+ of Capacity.  Another fine example is the Al-811 and AL-811H except this time tubes don't just burn out instantly, they give up their lives slowly when pushed past the limits. Luckily most Hams are smart enough not to push these Amps to the Levels that Ameritron says they can do.
 

I agree, many who comment here have not owned a SS amp nor have they had experience with tubes of recent manufacture. And they are not electronic engineers.

They attribute ALS-1300 failures to design defects. But as I have pointed out, and the designer of the amp has pointed out, the problems are due to workmanship. .  
Logged
WX7G
Member

Posts: 6048




Ignore
« Reply #86 on: March 11, 2011, 05:38:25 PM »

The ALS-600 is considered by some to be bullet proof. It uses four MRF-150 MOSFETs at 600 watts. the ALS-1300 uses eight MRF-150 MOSFETs at 1200 watts. If the ALS-600 is not driving the transistors to destruction the ALS-1300 is not.

Note that the brand new THP HL-550FX amp uses four MRF-150 type transistors at 600 watts. They run the same power per device that Ameritron does.

On cutting the amp down to 1000 watts the assumption is being made that Icom runs this power to be gentle on the MOSFETs. Might they be running 1 kW because they their marketing department decided that 1 kW is the place for their amp to sell? They get by with a smaller power supply, a smaller box, smaller heatsinks, and less air volume at 1 kW. Motorola, Ameritron, and THP all think 150 watt output per device is ok.

Take a look at the MRF-150 power dissipation rating of 300 watts. When running on-off keyed CW both amps dissipate 75 watts per transistor.

Ultimately it comes down to die temperature. The die-to-case thermal resistance of the MRF-150 is 0.6 deg C/W. At 75 watts the die is running at 45 degrees C above the case temperature.

I suspect that the Ameritron assemblers are incorrectly mounting the occasional MRF-150. A little too much heatsink paste, too little, or not enough torque on the screws. We had this same issue at an industrial power supply company I worked for. Applying heatsink paste with a silkscreen, giving the assemblers torque wrenches, and a full-power burn-in fixed this issue. Only one incorrectly mounted transistor out of every 1600 and Ameritron will have a 1% field failure rate.

I'll measure the heatsink temp on my ALS-1200 at a known dissipation and post it here. From that we'll know the die temperature.
« Last Edit: March 11, 2011, 05:40:48 PM by WX7G » Logged
W8JX
Member

Posts: 5785




Ignore
« Reply #87 on: March 11, 2011, 06:24:08 PM »

I am an Electronic Engineer for 26 years and I own a Tokyo Hy-Power SS Amp and I have owned a Swan Tube Amp and I have also rebuilt a Kenwood TL-922.
So whats your point!  It does not take an Electronic Engineer to see that if you use a Bank Of FETS that are rated at 1200 Watt Maximum and then use them in a Amp set to put out 1200 Watts that it's only a matter of time before they Fail or the PS Fails.  On top of that, that's exactly what is happening; so I just don't get your point!

Touchy aren't we. You are not only one with a engineering background here
 

  If your saying that Ameritron workmanship is Crap then that's just another reason to stay away from the Amp.  As I pointed out in an earlier thread, the Yaesu Quadra and several other Amps use the same eight FETS in the PA yet they rate their amps at 1000 Watts, so are we to believe Ameritron just figured out something that none of the others could or that they just plain wanted to use the typical MFJ standard of rating everything at it's theoretical maximum. I am truly happy that they must be suffering a big $$ loss with this Amp, let it be a lesson to them to stop pushing and Rating everything at 100%+ of Capacity.  Another fine example is the Al-811 and AL-811H except this time tubes don't just burn out instantly, they give up their lives slowly when pushed past the limits. Luckily most Hams are smart enough not to push these Amps to the Levels that Ameritron says they can do.
 
I never said they build crap, I did say that they over rate some of their products for marketing reasons. As I have said before I think their AL-82 is build like a tank and for about same money it is 2 or 3 times the amp a AL1300 is. And, on 811 amps, many have found out hard way that the 3 tube 600 watt rated amp it really a 400 to 450 watt unit and the 4 tube one is a 500 to 600 watt unit not 800 if you want it to last. Also I feel that AMeritron focuses on marketing so much that they cut corners. Example with 811 amp they brag how quiet it is and yet if they moved more air through it even at expense of a little more noise they would likely take abuse far better. Cooling is one place you never cut corner on in a amp.
Logged

--------------------------------------
All posted wireless using Win 8.1 RT, a Android tablet using 4G/LTE/WiFi or Sprint Note 3.
WX7G
Member

Posts: 6048




Ignore
« Reply #88 on: March 12, 2011, 09:42:42 AM »

The mistake I keep seeing here is how folks are reading the MRF-150 datasheet. The mistake is thinking that the 150 watt RF output spec is set by reliability concerns. It is not. It is set by distortion product concerns.

Reliability is obtained by operating the device below the maximum ratings of 125 volts, 16 amps (continuous), and a junction temp of 200 deg C. Derating from these numbers will give higher reliability and an idea of how much can be found by using MIL-HDBK-217.

The ALS-1300 operates the devices like so when run with 50% duty cycle on-off keyed CW: 100 volts, 5 amps, and junction temp <45 deg C above the heatsink temp. When I measure the heatsink temp we'll know the junction temp. All of this points to good device derating.

Designing the amp for 1000 watts, rather than 1200 watts, would change these numbers to 90 volts, 4.8 amps, and 38 degrees.
Logged
KD8MJR
Member

Posts: 2275




Ignore
« Reply #89 on: March 13, 2011, 10:48:47 PM »

If you go back a few pages you will see that an ALS-600 owner chimed in saying that he could only get 500 Watts out of his, I think in the case of the ALS-600 there is a power supply limitation that saves the FETS from burning out, in the ALS-1300 they seem to have a PS that can do the Job, but it will either burn itself out in the process or the FETS.
Also add into the mix the fact that 95% of Hams use watt meters that are have 10-20% accuracy level, so one has to be weary of power reports from just anybody.

Also looking back you will see that I stated that in the Hands of a good manufacturer you might get away with running at higher power levels but with Ameritron that becomes a seriously risky business, in the case of Tokyo Hy-Power if they say 600 watts you can bet they did some serious engineering to make sure their amps wont be coming in for repairs.

Your last statement about too little or too much paste, goes back to my statement that in the Hands of Ameritron you just don't want to run a device at 100% max, because the construction is always suspect.

The ALS-600 is considered by some to be bullet proof. It uses four MRF-150 MOSFETs at 600 watts. the ALS-1300 uses eight MRF-150 MOSFETs at 1200 watts. If the ALS-600 is not driving the transistors to destruction the ALS-1300 is not.

Note that the brand new THP HL-550FX amp uses four MRF-150 type transistors at 600 watts. They run the same power per device that Ameritron does.

Snip

I suspect that the Ameritron assemblers are incorrectly mounting the occasional MRF-150. A little too much heatsink paste, too little, or not enough torque on the screws.

snip

I'll measure the heatsink temp on my ALS-1200 at a known dissipation and post it here. From that we'll know the die temperature.

Logged
Pages: Prev 1 2 3 4 5 [6] 7 8 9 Next   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!