[Amps] NXP 65V LDMOS 1K80H-1800W

[Jim Thomson]

Date: Sun, 24 Dec 2017 01:01:39 +0000
From: Bill Turner <dezrat at outlook.com>
To: Amps group <amps at contesting.com>
Subject: Re: [Amps] NXP 65V LDMOS 1K80H-1800W


<I checked the website for SPE, looking for duty cycle specs but didn't
<see any. Does anyone know what they are?

<73, Bill W6WRT

###  Excellent  question.  And ditto with the new Flex...power genius..with its mystery 100%  ICAS rating.  
IMO, 100% ICAS means talk on ssb or cw  all day long.... but dont do something stupid, like a rtty contest.  

##  These SS amps are typ 50% eff at best, so with 1.5 kw out requires 3 kw dc input.
Dissipation of course is 1.5 kw.    Thats a bunch.  And a huge amount  if running rtty,
FT8, any other digital mode, or FM etc. 

##  any tube amp running just 60% eff, would only require 2.5 kw dc input...and   dissipation
is now down to just 1 kw. 

##  On the lower 3 bands,  with the same tube amp on 160-80-40,  68-70% eff is readily achievable.  
Now the diss is down even more, to just   706-  643 watts. 

##  helluva big difference between  1500 watts ccs diss on the SS amp..and the  643- 1000 watts
CCS diss  of the SS amp. 

##  It would require some exquisite  heat sink design to be able to dissipate 1500 watts  CCS of heat.
This is where the SS amp should be using a   19 inch wide rack mount heat sink, very deep, and very tall,
like 12 inches or more, and lotsa air on it.    Loads of fins, and very thin fins. 

## that or some elaborate cooling setup, with a liquid cooled heat sink and an external air cooled radiator +
mating water pump. 

##  ideally the way to manage heat is to generate less of it in the 1st place, like through higher eff,  which
appears is not going to happen any time soon with typ class AB  SS amps. 

##  I would like to see what both these amp manufacturers  have to say about  duty cycle.  
If they are  1.5 kw  ICAS,  I will pass on em for now, not for the $7K price tag. 

Jim  VE7RF