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Author Topic: New Legal Limit SS Amplifier coming soon  (Read 16376 times)
WA7PRC
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Posts: 2319


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« Reply #15 on: November 26, 2015, 10:13:24 PM »

I think there is a well-defined solid state amp market segment, folks who use them mobile, or who think they need truly instant (not even fractional second auto-tune is good enough for them) QSY.
Then, in order to keep the SS devices from folding back power due to a high VSWR, they add a tuner downstream. It takes time for an ATU to resolve the problem... in many milliseconds!  Wink

My olde toob amplefire doesn't much care about VSWR. Once I set the tuning (it takes a whole 5 seconds), it's good pretty much anywhere in that band segment. The style doesn't match my other gear but, I don't care about that (and no one will know if I don't tell them).  Wink

Bryan WA7PRC
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DL8OV
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Posts: 1051




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« Reply #16 on: November 27, 2015, 12:19:43 AM »

An IMD figure of 39.5 dB is very good and they probably achieve this by using multiple devices, a high voltage power supply (well, over 13.8V) and not overdriving anything including the transformer cores. It is however expensive BUT this is what you need to do if you want a clean signal heading up your coax.

Peter DL8OV
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W3RSW
Member

Posts: 606




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« Reply #17 on: November 27, 2015, 11:49:57 AM »

Schematics seem well thought out and complete but the amp itself seems not to be even prototyped yet. All pictures so far are artist's renditions, airbrushed or CAD photoshopped, etc.
All vaporware so far?  I do like the thermographic image though.  Not too many of those blowing around.  Grin

Nice pages outlining price, warrenty and return authorization though.
More web design than product it seems.
I wish them luck. They're entering the realm of Alpha's (and two following outfits) super tuner.
--A very expensive proposition currently delayed by several years.
« Last Edit: November 27, 2015, 12:09:59 PM by W3RSW » Logged

Rick, W3RSW
W3WN
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Posts: 839




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« Reply #18 on: November 27, 2015, 12:58:48 PM »

The owner of the company is KK3AN, who recently re-acquired AN Towers (which he founded) and who is very active on QRZ.COM

Maybe you should ask him your questions directly?
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KD8MJR
Member

Posts: 5533




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« Reply #19 on: November 27, 2015, 02:28:12 PM »

Schematics seem well thought out and complete but the amp itself seems not to be even prototyped yet. All pictures so far are artist's renditions, airbrushed or CAD photoshopped, etc.
All vaporware so far?  I do like the thermographic image though.  Not too many of those blowing around.  Grin

Nice pages outlining price, warrenty and return authorization though.
More web design than product it seems.
I wish them luck. They're entering the realm of Alpha's (and two following outfits) super tuner.
--A very expensive proposition currently delayed by several years.

A friend of mine says he has seen one in the flesh and seen it operate.  Some case work design is still in the works that is why they are showing CAD drawings.

73s
Rob
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“A lie can travel half way around the world while the truth is putting on its shoes.”  (Mark Twain)
KK3AN
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Posts: 42




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« Reply #20 on: November 27, 2015, 04:21:44 PM »

Eighteen of us are testing (3) prototypes internally, and we're now building a 4th in final form, with several changes made.

Dan KK3AN






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W3RSW
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Posts: 606




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« Reply #21 on: November 28, 2015, 05:30:11 AM »

Very nice. Thank you for the "reveal."  Grin
I sure understand it's a labor of love at this point.
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Rick, W3RSW
W8JX
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Posts: 13268




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« Reply #22 on: November 28, 2015, 06:53:58 AM »

For a legal limit SS amp I would expect to see more heat sink mass and surface area than in these picture. 1500+ watts to dissipate while keeping junction temperatures safely below critical temperatures is a tall order. I suspect that it will fold back output sooner than later in key down modes. Proper heat sinks cost money and add size and mass that does not usually fit with marketing needs.
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Ham since 1969....  Old School 20wpm REAL Extra Class..
KK3AN
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Posts: 42




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« Reply #23 on: November 28, 2015, 07:25:54 AM »

The heat sink / spreader assembly is not pictured.
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KH6AQ
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Posts: 7776




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« Reply #24 on: November 28, 2015, 07:36:24 AM »

The main power supply looks to be an off-the-shelf unit. I like that.
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W8JX
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Posts: 13268




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« Reply #25 on: November 28, 2015, 08:06:52 AM »

The heat sink / spreader assembly is not pictured.

Granted but case is as well as fan and heat sink design and size is limited given available area in case. I feel it lacks serious cooling (which most SS amps do) to limit cost and size. Best heat-sinking material is copper and that is expensive and heavy and seldom used for these reasons.
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--------------------------------------
Ham since 1969....  Old School 20wpm REAL Extra Class..
KH6AQ
Member

Posts: 7776




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« Reply #26 on: November 28, 2015, 09:34:05 AM »

The Dedicated RF website has this to say about the thermal design:

"PA cooling design has been optimized to provide maximum airflow directly at the FETs and heat spreader cooling fins, followed by an immediate exhaust path by way of our custom designed wide exhaust duct near the center of the amplifier chassis. Our heat spreader consists of a block of Alloy #110 copper with 99.9% purity, custom CNC'd for our PA board with .400" thickness, interfacing with an extruded aluminum fin block."
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W3RSW
Member

Posts: 606




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« Reply #27 on: November 28, 2015, 12:07:46 PM »

Yes Reviewing the thermographpage,  I would say calcs have been done.

http://www.dedicatedrf.com/thermal.html

Note that there is almost 1/2 in. tk. Cu plate.
« Last Edit: November 28, 2015, 12:34:50 PM by W3RSW » Logged

Rick, W3RSW
K6AER
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Posts: 5689




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« Reply #28 on: November 28, 2015, 04:03:15 PM »

Dan,

Give me a call regarding the FCC emissions testing.
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AF6LJ
Member

Posts: 580




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« Reply #29 on: November 29, 2015, 06:17:41 PM »

Looks good, looking forward to seeing this go to market.
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Take Care
Sue,
AF6LJ

Don't Kalifornicate My Life
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