[Amps] RF-KIT SS AMP

[Jim Thomson]

Date: Thu, 1 Jun 2017 18:48:55 +0000
From: Bill Turner <dezrat at outlook.com>
To: Amps group <amps at contesting.com>
Subject: Re: [Amps] RF-KIT SS AMP

<It looks pretty good on paper but the real world sometimes has
<unpleasant surprises in store. I wouldn't buy one until it gets
<reviewed by an independent third party such as QST. It's real easy to
<lay out $3k and before long wish you hadn't. 

<A word to the wise. 

<73, Bill W6WRT


##  agreed,  qst..or at least a handful of experienced  tech savvy types,  who can
make meaningful  measurements..including imd, etc,  and offer a critque. 

##  I also noticed they reduce power output by reducing the current limit on the power
supply.... vs  reducing drive.  This method, I have not heard of before.   One would think it
would flat top 1st..once it hit the current limit threshold ?   But I have zero experience with it. 

##  I have zero experience  with SS amps.  My concern is the TX  IMD products.  Reducing 
drive and PO is one method that would work..but eff  goes to hell..fast.  Diss then increases  with just
the typ 35% when po reduced.... while maintaining 48-50 vdc.

##  another method  to reduce IMD  may be to just increase the idle current  a bunch.
I have no experience with that either..except on tube amps.   But I suspect the eff might creep  up
a little, and perhaps slightly reduced  IMD.  Then again, the increased idle current would result in
a higher average dissipation.   

##  A combo of reduced drive, and higher idle current might be the ticket,  but Im just speculating. 
The faster 120mm fans could be used to handle the increased  idle current.  Its not like the SS amp
has to reside on the desk, it could sit anywhere...like in  my shop next door. Noise problem solved.

Jim   VE7RF