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

donate to eham
   Home   Help Search  
Pages: Prev 1 [2] 3 4 5 6 7 8 Next   Go Down
  Print  
Author Topic: Any News on the new Legal Limit Amps from Elecraft and Flex  (Read 24619 times)
W8JX
Member

Posts: 13268




Ignore
« Reply #15 on: June 03, 2017, 07:21:10 AM »

As for the efficiency of a tube amp not dropping much, perhaps you should look at the wall meter vs doing the P=IV calculations from the respective meters... for one, heater current on any decent tube amp is going to significantly add to your idle consumption... and unless you're a contester then you're going to be doing a fair amount of idling vs transmitting...

If you are using 3cx800's or 8877 and such filament current is peanuts. Even my old Dentron with 4ea 572's only uses 100 watts to keep lights lit. Not a good argument to make up for poor SS amp efficiency.


The minute pre-disortion starts being built into IC-7300 style SDRs tube amps under 4Kw are dead...

No not at all. (maybe for those with DEEP pockets) The tipping point will be price and reliability not IMD. (some like to preach about what a problem it is when it is not)  Reliability is will drive up cost because it will require better cooling for SS devices because they have a never exceed temp after which they become a paper weight. Tube have no such barrier as melt down is well beyond tubes normal ratings. Until SS can match price and reliability tube are going to be viable for some time.
Logged

--------------------------------------
Ham since 1969....  Old School 20wpm REAL Extra Class..
KC4ZGP
Member

Posts: 1961




Ignore
« Reply #16 on: June 03, 2017, 07:51:54 AM »


$7,000.00 for an amplifier!?

It better make my morning coffee.

$7,000.00 for an amplifier!?

Back to the paddle, 18.087MHz.

_ _ ... ... _ _

Kraus
Logged
N2RJ
Member

Posts: 2100




Ignore
« Reply #17 on: June 03, 2017, 08:56:06 AM »

Someone said that for all intents and purposes tube amps are obsolete.  I agree because why would anyone want to pay $3500 for a tube amp when they can get the same power output in a solid state amp for $6500.
Art

Now that is silly, I will pay twice as much for same power but less reliability and higher repair costs. A decent tube amp is is far more rugged and easy to repair. high power SS device have a way of going obsolete several years after they come out while tubes for tube amp have been available for decades. Aso you can reduce drive on a tube amp to reduce output and and efficiency of tube amp does not drop much but with a SS amp it can run just as hot at 50% power as full because efficiency, which BTW is markedly less with a SS amp, goes down hill quick as drive is reduced.

Tubes are more forgiving than SS device will still be viable until SS amp get cheaper and more reliable and cheaper/easier to repair.

Your efficiency figures are probably with older devices. The newer LDMOS devices pretty much take tubes to the woodshed. This is why tube amp manufacturers are jumping all over them compared to
previous generations of solid state devices. Tubes are more forgiving except for LDMOS which can survive 66:1 SWR, dead short or open at full output. Repair costs are another busted myth as well. At $200 per transistor, replacing all of the finals in a high end LDMOS amp will be not much more than replacing 4x572b in an AL811H. In a ceramic tube amp you're looking at $800 per tube for chinese tubes, probably closer to $1500 for a quality replacement (if you can find it).

Logged
N9AOP
Member

Posts: 1173




Ignore
« Reply #18 on: June 03, 2017, 09:54:07 AM »

  Guys, I have nothing against SS amps except the price point of the ones just announced.  The OM POWER 2000+ is $3500 and outputs 2KW.  When will I be able to buy a SS amp that will run the same power (key down like an ALPHA) for the same price?   Or is it bad business practice not to sell the thing for $6000 since hams will pay that price?
Art
Logged
KC4ZGP
Member

Posts: 1961




Ignore
« Reply #19 on: June 03, 2017, 09:57:23 AM »


You want solid state...BUILD! Fancy them up to your liking.

And I see you still forgot to mention the ever so state-of-the-art E-104 amplifier.

Back to the paddle at 18.087MHz.

_ _ ... ... _ _

Kraus
Logged
K6AER
Member

Posts: 5743




Ignore
« Reply #20 on: June 03, 2017, 10:24:57 AM »

I have been transmitting when my station in Colorado took a lightning strike. Blew the fuse on the 8410. No. Other damage.  I'll bet I would not have been so lucky even with a LDMOS amp.

Although SS amps have their advantages several laws of physics and repair isues still apply.


No soft compression.

Devices can be expensive expecially  when they are no longer used commercially.

Narrow output impedance range.

Good harmonic supression require diplexers for over 1200 watts out.

Sensitive to power up spikes.

Most hams will not have equipment or skills to repair their SS amps. Replace a transistor on a PCB and many times the board is toast.

Good IMD performance requires >2 dB of power reserve.

Mid power efficiency is low.

Product support after 10 years is scarce. Especially if the company goes belly up.

These are just a few reasons the Twilight Years of tube amplifiers is a bit premature.
« Last Edit: June 03, 2017, 10:29:04 AM by K6AER » Logged
N2RJ
Member

Posts: 2100




Ignore
« Reply #21 on: June 03, 2017, 04:16:50 PM »

  Guys, I have nothing against SS amps except the price point of the ones just announced.  The OM POWER 2000+ is $3500 and outputs 2KW.  When will I be able to buy a SS amp that will run the same power (key down like an ALPHA) for the same price?   Or is it bad business practice not to sell the thing for $6000 since hams will pay that price?
Art

You can buy B26-PA for 2700 Euro and it has a built in ATU. 2x LDMOS, 2kw capable.

I'm sure when Ameritron starts making them they will cost about the same.
Logged
N2RJ
Member

Posts: 2100




Ignore
« Reply #22 on: June 03, 2017, 04:21:33 PM »

I have been transmitting when my station in Colorado took a lightning strike. Blew the fuse on the 8410. No. Other damage.  I'll bet I would not have been so lucky even with a LDMOS amp.

You got lucky. There are other components inside of even tube amplifiers that could have been fried. Not to mention top end tube amps have lots of computer circuitry in them.

On a side note we took a strike here, and the Icom ProIII just lost the CI-V port, nothing else was damaged.

Quote
Although SS amps have their advantages several laws of physics and repair isues still apply.
No soft compression.
Devices can be expensive expecially  when they are no longer used commercially.
Narrow output impedance range.
Good harmonic supression require diplexers for over 1200 watts out.
Sensitive to power up spikes.
Most hams will not have equipment or skills to repair their SS amps. Replace a transistor on a PCB and many times the board is toast.
Good IMD performance requires >2 dB of power reserve.
Mid power efficiency is low.
Product support after 10 years is scarce. Especially if the company goes belly up.
These are just a few reasons the Twilight Years of tube amplifiers is a bit premature.

I think that most of those apply to legacy designs, not LDMOS. The economy of scale now is that they are using 2 devices instead of one to get the >2dB of power reserve, plus technologies such as adaptive predistortion can help greatly with IMD.

The broadcast world (except maybe for really, really QRO) has shifted to solid state. Even microwave ovens are going solid state.
« Last Edit: June 03, 2017, 04:23:39 PM by N2RJ » Logged
K6AER
Member

Posts: 5743




Ignore
« Reply #23 on: June 03, 2017, 04:45:49 PM »



The broadcast world (except maybe for really, really QRO) has shifted to solid state. Even microwave ovens are going solid state.
[/quote]

I see 1100 watt MW Ovens selling at $60.00. Why would you need solid state ovens with a 1 second filliment heating time?
Logged
W9FIB
Member

Posts: 2529




Ignore
« Reply #24 on: June 04, 2017, 04:03:26 AM »

High Power Solid State is constantly moving forward in both development and application. As Hams, we have only just begun to see this.

In the world of inverters that I currently work, the changes have been impressive. Controlling thousands of HP in a single small air cooled cabinet is becoming the norm now. And that same R+D is going on in the RF world as well. Higher reliability and less loss converted to heat are driving out many old systems whether tube or solid state.

Someone talked about 100 watts in stand by.  I would much rather have something that uses less then 10 watts on standby. And stops generating heat on stand by. Which reduces fan running time which also increases overall power efficiency.

That's the name of the game in the near future. Reliability and efficiency. And when it becomes the norm, prices will drop as well. But only if we hold the amplifiers manufacturers feet to the fire. In the industrial world, HPSS has become the norm. And competition between the SS device manufacturers is causing continuous price lowering and efficiency gains. I think this will begin soon in the RF world soon. If not already. The drive for power efficiency everywhere in the world in everything that uses electricity will change the way things are done.

Besides, wouldn't you want to use less electricity as rates increase? To do that and maintain what ever power level you use means making that power level more efficiently. Tubes will never meet that goal. Even old SS devices help some. But can't hold a candle to the stuff coming out today. And the future keeps looking better.
Logged

73, Stan
Wisdom is knowledge you gain after you know it all.
N3QE
Member

Posts: 5593




Ignore
« Reply #25 on: June 04, 2017, 05:44:53 AM »

Someone talked about 100 watts in stand by.  I would much rather have something that uses less then 10 watts on standby. And stops generating heat on stand by. Which reduces fan running time which also increases overall power efficiency.

I believe some of the switching P/S solid-state units will turn off or at least quiesce the switcher on receive, and then quickly and glitchlessly ramp it up on transmit, and then seamlessly quiet the switcher when switching back to receive. At which point it's down to just a little bit of control circuitry drawing power (a few watts).

Just to throw the few watts vs 10 watts issue into sharp contrast, a 3CX3000A7 filament is about 400W. Makes 50W in the 8877 filament seem like nothing!
Logged
W8JX
Member

Posts: 13268




Ignore
« Reply #26 on: June 04, 2017, 06:23:59 AM »

Your efficiency figures are probably with older devices. The newer LDMOS devices pretty much take tubes to the woodshed. This is why tube amp manufacturers are jumping all over them compared to
previous generations of solid state devices. Tubes are more forgiving except for LDMOS which can survive 66:1 SWR, dead short or open at full output. Repair costs are another busted myth as well. At $200 per transistor, replacing all of the finals in a high end LDMOS amp will be not much more than replacing 4x572b in an AL811H. In a ceramic tube amp you're looking at $800 per tube for chinese tubes, probably closer to $1500 for a quality replacement (if you can find it).

Efficiency is a weakness of SS devices and the use of no tune broad band tuning does not help efficiency either. It is quite possible to make a no tune tube amp (Amp Supply, formally Dentron, actually made one) but then efficiency is not much better that that of a SS amp.

I think that many by SS amps because they require a lot less skill/knowledge to use and are basically plug and play.
Logged

--------------------------------------
Ham since 1969....  Old School 20wpm REAL Extra Class..
K7JQ
Member

Posts: 1306




Ignore
« Reply #27 on: June 04, 2017, 07:34:43 AM »

I think that many by SS amps because they require a lot less skill/knowledge to use and are basically plug and play.

True, but unless you have fairly resonant antennas (broadbanded below about 1.9:1), you will need a high power ATU. If it's not automatic, you're still fiddling with knobs. The better manual tune tetrode tube amps (Acom, OM) have switchable input attenuators that let you tune up easily with LED indicators, at full exciter drive. Fully protected against mistakes. Band changes and tune up takes maybe 10-15 seconds. No tuner needed with SWR up to 3:1. Warmup and tune up times are really only a consideration if you're a "competitive" contester, or worried that your ATNO DX will go QRT before you have a chance to call him. Is that worth thousands of dollars more? Personal choice.

Pros and cons with each, but technology is dictating the future is solid state. However, IMO, (manual tune) tube amps will still be around as long as they're considerably less expensive than legal limit SS amps.
Logged
W8JX
Member

Posts: 13268




Ignore
« Reply #28 on: June 04, 2017, 07:45:54 AM »

Pros and cons with each, but technology is dictating the future is solid state.

Of that I do not disagree. What I do disagree on is the time line on which they will fully replace tube amps. I do not see that happening for many years yet. Myself I doubt I will ever go SS or auto tune amp. Too old school and would not feel like I was operating or in control if I was not tuning it manually
Logged

--------------------------------------
Ham since 1969....  Old School 20wpm REAL Extra Class..
VK3BL
Member

Posts: 1790


WWW

Ignore
« Reply #29 on: June 04, 2017, 07:49:56 AM »

Solid state amps are now:

1) The same price or cheaper than equivalent tube amps (auto, CAT/CI-V control, multi antenna ports with auto selection)
2) Just as reliable, if not more so (these forums are not full of LDMOS failures)
3) Much lighter than a tube amp
4) Just as efficient (total system) if not more so than tube amps

As it stands you'd only buy a new tube amp if you wanted:
1) 4Kw+
2) Were obsessed with IMD & owned a Class-A rig
3) Were on a budget, but didn't mind replacing quads of $20 tubes every year or so.

As far as availability is concerned, you can still buy most of the popular FETs, just like you can still buy most of the popular tubes.  The FETs however are cheaper and of better quality.

Logged

J.D. Mitchell BA  - VK3BL / XU7AGA - https://www.youtube.com/ratemyradio - Honesty & Integrity
Pages: Prev 1 [2] 3 4 5 6 7 8 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!