[Elecraft] KPA1500

[Kevin Stover]

I am a fan of Klitzing's designs.

I did a rough and fast add up of all the stuff needed to build one of 
his 1KW designs using assembled and tested boards.
I came up with right at $2K. That's just parts. No sheet metal, no 
fasteners, no wire, no fans, NO 50V - 40A switching power supply. You 
won't be running it on 120V and it won't fit in a K3 case.

The LPF he uses could be improved. He uses a 5 pole Chebishev with SMT 
Mica caps.
I'd use the 5 pole Cauer from the SSPA project in the 2012 Handbook, 
sized for 1.5KW. It uses ceramic SMT caps (more expensive but worth it 
for a clean amp). Using the Cauer design means tuning the LPF with a 
network analyzer to place the nulls on top of the odd order harmonics.

Someone has commissioned Jim to build a 2KW version of his 160-6m SSPA. 
Basically two of his 1KW amps throttled back to 750W, in one box with a 
high power splitter/combiner. The power supply jumps to 50V, 60A and it 
still won't fit in a K3 case. The two 10"x10"x4" aluminum heat sinks 
weigh 10 pounds combined. It will not be a quiet amp but might actually 
do full power RTTY all day.


On 2/20/2016 1:22 PM, Edward R Cole wrote:
> Well reading Wayne's response maybe one should look elsewhere for a 
> kilowatt or more HF linear.  I particular I would suggest looking at 
> the LDMOS amp kits and assembled amps recently available (e.g. W6PQL)
> http://www.w6pql.com/1_kw_sspa_for_1_8-54_mhz.htm
>
> I have built some of his 2m amp and his 23cm amp kits.  Really have to 
> wonder where the ham "build-it" spirit has gone?  But Jim will build 
> on contract if you got the money (which apparently there are quite few 
> that do).
>
> Maybe someday I will have Jim build the amp pallets for me to 
> incorporate into a full amp of my own design.  He really offers a lot 
> of subassemblies which one can combine.
>
> 73, Ed - KL7UW
>
>


-- 
R. Kevin Stover
AC0H
ARRL
FISTS #11993
SKCC #215
NAQCC #3441


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