[Elecraft] OT: SPE expert 1k-fa

[Paul Christensen]

Johnny,

It's definitely not "silk smooth."  I am using a K3 with the SPE 1K-FA. 
Overall, I'm happy with the performance of the SPE amp with some changes. 
However, if you value QSK, be aware that QSK was not fixed until Rev 4 was 
released at the beginning of this year.  Older SPE amps require a new F/W 
chip and a hardware PCB change.  Still, the operation of the relays is 
extremely loud -- too noisy IMHO for enjoyable QSK.  Older SPE amps will 
hot-switch, even at low keying speed.

It's possible to handshake the SPE amp and the K3 together to avoid 
hot-switching, but be prepared for CW timing problems that must be corrected 
with an external keyer.  I devised my own silent, high-power QSK system 
using an Ameritron QSK-5 and a homebrew optically-coupled interface.  A 
schematic can be seen on my QRZ.com page.

http://www.qrz.com/db/W9AC

Also, be prepared to see output power swing 10% based on the PA deck 
temperature.  This is a problem I've seen with most solid-state amps, even 
amps that include temperature compensation circuitry.

Finally, the rotational fans go through several steps as PA deck temperature 
changes, the last of which produces noise at a level that competes with an 
aircaft jet engine.  The state-of-the art in PA deck cooling has a long way 
to go in order to match the best VT amps.

Despite these issues, the SPE amp has been reliable and it takes quite a bit 
of mis-use to put it into a fault condition. 1KW is easily attained on all 
bands.

Paul W9AC

----- Original Message ----- 
From: "Johnny Siu" <vr2xmc at yahoo.com.hk>
To: "Elecraft" <elecraft at mailman.qth.net>
Sent: Wednesday, November 17, 2010 9:58 AM
Subject: [Elecraft] OT: SPE expert 1k-fa


Hello Group,

While KPA500+KAT500 are in the production plan, do any of you use SPE expert
1k-fa with your K3? How is the integration? Is it silk smooth?

I am thinking whether I should get the SPE or wait for the KPA500+KAT500 
which
have been talking about for some years.

Price of SPE here is US$3,800 so I am also thinking of the price 
differential
with KPA500+KAT500.
cheers,


Johnny VR2XMC



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