[Amps] Expert 2K / lack of specs

[Jim Thomson]

Date: Tue, 5 Mar 2013 09:34:17 +1030
From: "Leigh Turner" <invertech at frontierisp.net.au>
To: <amps at contesting.com>
Subject: Re: [Amps] Expert 2K / lack of specs


Gentlemen,

I would not worry too much about the lack of specs; they would be quite
predictable and probable mediocre in respect of IMD performance.

All that really counts is that users of the Expert 1K or 2K amp do not cause
a nuisance to other adjacent users of the band in terms of IM crud and
buckshot and the SSB signal is not too wide in frequency occupancy; if any
amp meets that key criteria, then it is good enough for ham use.

The ones that I've heard on air meet this criterion.

Leigh
VK5KLT

## say what?    When you spend between $5K-$10K  on an amp,  it damn
well better come with specs well beforehand, lotsa of em, and it had better
meet those specs. 

##  You are probably correct.  IMD is probably lousy like –24 to –30 db pep,
typ ham junk.    You could drop the drive down a bit...and clean up the imd,
but then it runs inefficient.   Hence the lower power levels on some of the SS
amps, like 500-1000-1500w merely lower the voltage a bit,  so the Z’s stay
the same, and eff stays the same.   Problem is the imd does not improve. 

##  what they need to do is design a real low imd 1.5 kw amp...such that
Z’s come out correct for the combiners used etc.

##  Plan B is just buy a commercial grade marine amp.  Then you get the
real deal.   Then it will have low imd, and meet fcc/itu specs. 

Jim   VE7RF