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Author Topic: Flex 1.5kw Amp, new photo, more details...  (Read 32595 times)
KH6AQ
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Posts: 8008




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« Reply #15 on: December 08, 2016, 07:54:30 AM »

I'm guessing what Flex means is 100% duty cycle modes (AM, RTTY) with typical amateur 5 minute ON, 5 minute OFF operation.
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W3RSW
Member

Posts: 609




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« Reply #16 on: December 08, 2016, 08:47:00 AM »

IVS service specifically documented in Eimac Amateur Service Bulletin AS-40, W6SAI using the the 8873 family of triodes as example. -- oscilloscope pictures and detailed description over several pages provided in that bulletin.

Spec sheet for the 8873 family as copied by and Tnx to G8WRB

http://www.g8wrb.org/data/Eimac/8873.pdf

Note that mention is made for intermittant service in the tube specs fairly far beyond the CCS specs.
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Rick, W3RSW
KD8MJR
Member

Posts: 5557




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« Reply #17 on: December 08, 2016, 08:52:05 AM »

Marketing 1: "People over at eham don't like the case of the prototype, says it would look good next to a 1970s CB"
Marketing 2: "Get engineering to paint it black and put a green led in it, hams need their amps to glow"
Marketing 1: PowerGenius!

 Grin Grin
I really do not like the exterior.  What happened to all the buttons and knobs?  Why does that cover plate look so much like the old Intel Plates that would come pre glued onto the PC's housing?




73
Rob
« Last Edit: December 08, 2016, 08:55:02 AM by KD8MJR » Logged

“A lie can travel half way around the world while the truth is putting on its shoes.”  (Mark Twain)
NO9E
Member

Posts: 888




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« Reply #18 on: December 08, 2016, 12:24:44 PM »

Aside from trivialities, there is possibility of having a no-tune, fully automatic, clean 2 KW radio that cannot do wrong. This assumes that the amp will have an ATU.

Your work: Choose antenna and power level.
System's work:
- select voltage to maximize efficiency,
- adjust ATU
- do precorrection
- adjust power level just below saturation

The result is maximum efficiency at low IMD, hopefully with a quiet fan.

Top setup for contesting especially that Flex has a new speech processing algorithm that makes 2 db more (see QEX)! But after a second thought, I am not convinced that the setup will work for all but the top stations. As one well know contester told me, the keys to good score when your setup is only good are clicks and high IMDs.   

Let's start a rumor about a disgruntled firmware programmer. Every time the amp works 20% above the stated limit, an automatic email follows to FCC, or during contesting, to appropriate contesting committee.







 



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VK3BL
Member

Posts: 1790


WWW

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« Reply #19 on: December 08, 2016, 04:44:46 PM »

ICAS ratings were introduced by RCA in the October 1939 RCA Ham Tips. It was expected that running at tube at ICAS ratings would give 50% of the life that would be obtained under CCS ratings - and it was pointed out that on CW, with the ratio of on to off, life was easier for the tube than the 100% carrier of CCS ratings.

So traditional ICAS ratings aren't applicable to solid state amplifiers. Thus the term is meaningless in its original definition and they need to say just what they mean by '100% duty cycle ICAS'.

The same arguments apply to IVS ratings - they meant something for tubes. They could mean much the same for a SS PA with a small heat sink, but it would need defining....

I'd say ICAS ratings a perfectly applicable to solid state amplifiers, if one is willing to let go of "50% of life" part.

More to the point, they're saying if you run this thing continually in a commercial environment, sooner or later the cooling will be insufficient and the final transistor(s) will die.

I think the core of the definition is translatable to solid state.
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J.D. Mitchell BA  - VK3BL / XU7AGA - https://www.youtube.com/ratemyradio - Honesty & Integrity
G3RZP
Member

Posts: 1327




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« Reply #20 on: December 09, 2016, 01:45:27 AM »

The problem is that unless or until THEY define what they mean by it, we are only guessing.
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VK3BL
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Posts: 1790


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« Reply #21 on: December 09, 2016, 03:16:04 AM »

The problem is that unless or until THEY define what they mean by it, we are only guessing.

Yeah, that is true.  I guess the community will form an opinion pretty soon once they're released, however.
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J.D. Mitchell BA  - VK3BL / XU7AGA - https://www.youtube.com/ratemyradio - Honesty & Integrity
W9OY
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Posts: 1843


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« Reply #22 on: December 09, 2016, 06:23:44 AM »

I emailed flex

 ICAS in a solid-state environment implies de-rating to keep the device junction and case temperatures within their maximum ratings. Thus, ICAS suggests a limited operating or 'on' period followed by an 'off' or standby period of at least the same or longer duration, whilst CCS (Continuous Commercial Service ) assumes continuous, key-down operation at reduced output (assuming the same heat sink area and/or fan air-flow rating for both applications).  

So it's basically about junction and case temp.  These amps are going to big deal contest stations so I doubt normal ham operation is going to phase the amp. Also the amp is fully protected against MAS (moronic amateur operation)

73 W9OY
« Last Edit: December 09, 2016, 06:30:17 AM by W9OY » Logged
N9AOP
Member

Posts: 1174




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« Reply #23 on: December 09, 2016, 01:49:30 PM »

So are you saying that if you put a brick on the key and leave it for a few hours that 400 watts would be a safe output and not fry anything?
Art
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ZENKI
Member

Posts: 1649




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« Reply #24 on: December 09, 2016, 02:06:26 PM »

Flexradio  should have a chat with AC2IQ. He has developed a very effective linearizer that would improve the IMD of this  new amplifier. AC2IQ has already implemented his  analog linearizer in the Flex5000 and many other radios with outstanding IMD performance results.  .
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KB2TIS
Member

Posts: 18




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« Reply #25 on: December 09, 2016, 02:26:28 PM »

Flexradio  should have a chat with AC2IQ. He has developed a very effective linearizer that would improve the IMD of this  new amplifier. AC2IQ has already implemented his  analog linearizer in the Flex5000 and many other radios with outstanding IMD performance results.  .

I'm sure hundreds of hams will line up to buy an even more expensive SSPA with a linearizer in it.

Or do you think that predistortion linearizers align themselves?
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ZENKI
Member

Posts: 1649




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« Reply #26 on: December 09, 2016, 03:09:58 PM »

Why a Analog linearizer  might be of more interest to many hams is that it becomes a plug and play solution. The Lineariser is installed at the factory and nothing else is needed after that and the end result is a ultra clean amplifier without too much fiddling.

Pre-distortion has many set up variables and requires setup and adjustment. Once setup it is  dynamic  and will always optimize the signal for maximum cleanliness.

The other point is that most hams dont use transceivers and amplifiers that can use the Clean Signal Pre-distortion system(Anan radios)in a drive chain. A analog linearizer board that can be retrofitted to any amplifier or radio would be more appealing to many hams who dont want to buy a new radio or amplifier.

I dont have much details about the AC2IQ board, so dont know what the full practicalities are for a working installation. I have just monitored signals using this board and the results are beyond excellent. You might want to contact AC2IQ for further details. I am not even sure if he is planning to sell his board or design commercially.

Flexradio  should have a chat with AC2IQ. He has developed a very effective linearizer that would improve the IMD of this  new amplifier. AC2IQ has already implemented his  analog linearizer in the Flex5000 and many other radios with outstanding IMD performance results.  .

I'm sure hundreds of hams will line up to buy an even more expensive SSPA with a linearizer in it.

Or do you think that predistortion linearizers align themselves?
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KB2TIS
Member

Posts: 18




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« Reply #27 on: December 09, 2016, 04:30:41 PM »

Why a Analog linearizer  might be of more interest to many hams is that it becomes a plug and play solution. The Lineariser is installed at the factory and nothing else is needed after that and the end result is a ultra clean amplifier without too much fiddling.

I'm quite aware of why it is desirable. The normal reasons for PD linearization don't apply to hams, so making an expensive SSPA even _more_ expensive doesn't  seem to be a recipe for greater sales.

Not to mention that the flex already has the hardware to do digital baseband linearization - it is lacking the software, afaik
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K6AER
Member

Posts: 5745




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« Reply #28 on: December 10, 2016, 08:52:39 AM »

Where would you interface an aftermarket Analog Linearizer in today’s modern radio. Would the real world benefits really improve the useful signal when IMD is down 35 dB and most signals on the band are only +20 dB above the noise floor on a good day?

Nobody is going to do surgery on their new IC/FT/TS 4000 shack in the box for a perceived problem when their biggest worry is putting up a dipole so the neighborhood CC&R ladies don’t see it.
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KK4YDR
Member

Posts: 673




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« Reply #29 on: December 15, 2016, 07:22:55 PM »

Ya'll are killing me. Groaning and mumbling and complaining about something that isn't even out yet, claiming it wont be this or that, or should be this or that. Well then start your own company and build whatever your heart wants. I for one am watching the AMP closely and could care less if it looks like CB or star trek as long as it performs as advertised. I would love to have an SDR interfaced Amplifier that works over Ethernet that I can couple with my Flex 6300 and have fully integrated radio chasing legal limit plus in an amplifier that weights little and can work on both 240 and 120v making it somewhat portable as well as FLEXable.

I am excited, I probably will not ever get to touch one unless they are sub $4000 and If I know Flex this is easily going to push $7999.99 on a good day.

And as far as IMD etc..... no one cares anymore apparently. Since now all of 40m is CB channel 6 and most of 75m has turned into Trucker Central. IMD, spurious transmissions, hell broadcast rap music ... whats the difference. I am not going to spend countless dollars so that CBers on the bands can have a nice clean signal from me just to trash my station with fart toys and sound generators. I am not far from honestly throwing in the towel and coming back in 10 years to see how things evolved. But I keep hanging around.

This is not a hypocritical statement to the fact I would love to own a very clean solid state linear that can chase my Flex around as it would be purpose built especially for the Flex 6000 line.
« Last Edit: December 15, 2016, 07:26:56 PM by KK4YDR » Logged
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