[Elecraft] High Tx IMD with new K3s/10

[Benny Aumala]

Thank you Bill,

You made my day.

When K3s is driving my JUMA PA1000 without 100W PA, the drive is

better than excellent up to 8W.

I need 2W for 600W clean output (-40dB) in SSB.

For CW 4W is enough for a 1000W output (measured with LP100 power meter).

Juma use this active element, and here are some interesting measurements 
for 144MHz:

http://www.nxp.com/products/rf/rf-power-transistors/rf-broadcast-and-ism/144-148-mhz-

1250-w-cw-50-v-2-meter-amateur-reference-design:RDMRFE6VP61K25H_2M_AMATEUR?fpsp=1&tab=Documentation_Tab

Benny   OH9NB

==============================================

Message: 6
Date: Fri, 24 Feb 2017 16:24:11 -0700 (MST)
From: Bill Leonard N0CU<billincolo73 at gmail.com>
To:elecraft at mailman.qth.net
Subject: Re: [Elecraft] High Tx IMD with new K3s/10
Message-ID:<1487978651422-7627339.post at n2.nabble.com>
Content-Type: text/plain; charset=us-ascii

Benny,

I recently had Elecraft replace a KLPA3A again. They also did the Tx IMD mod
and an alignment.
I am now seeing the following 3rd order IMDs:

4W   -40 dBc
8W   -40 dBc
9W   -35 dBc
10W -30 dBc
12W -20 dBc

What is also encouraging is that now the higher order IMDs (5, 7 & 9th) stay
at least 10 dB below the 3rd.
Some of these were equal or higher than the 3rd last summer when I was
discussing the problem with Elecraft. Obviously they have made some notable
improvements since then.
The two tone envelope still looks more like a square wave at 12W, but this
radio is spec'd as a 10W transmitter that is clean to -30 dBc, so it appears
they are now meeting their advertised spec.

Bill  N0CU