[Elecraft] KPA500

[Doug Faunt N6TQS +1-510-655-8604]

See my earlier note as to one reason it was chosen.  Elecraft learned from
the K2 about being a good player in a multi-TX environment (which can
just be neighbors).
Also, the 60V supply is providing no current when key up, and needs to
go to full output on key down- apparently this is less of a problem
with a linear supply than with a switcher.  And of particular
significance to CW ops.

BTW, much of what I'm writing is my repeating what I was told or heard,
and none of it is binding on Elecraft, and is subject to my
misinterpretation, as well as changes down the line.  The amp is still
in prototype, and has lots of testing to endure before it's solid.

I trusted them two years ago (i have K3 #22) and I trust them now.

73, doug

   From: "Bob McGraw - K4TAX" <RMcGraw at Blomand.net>
   Date: Sun, 18 Apr 2010 17:02:04 -0500

   I'll pass on linear supplies.  Too heavy, too inefficient.

   73
   Bob, K4TAX



   ----- Original Message ----- 
   From: "Doug Faunt N6TQS +1-510-655-8604" <faunt at panix.com>
   To: <RMcGraw at Blomand.net>
   Cc: <don at w3fpr.com>; <M0XDF at Alphadene.co.uk>; <elecraft at mailman.qth.net>
   Sent: Sunday, April 18, 2010 4:56 PM
   Subject: Re: [Elecraft] KPA500


   > It's not a switcher.  As is common for linear power supplies (and not
   > uncommon for switchers), there's an input voltage selector as part of
   > the input power connector/fuse/switch combo.
   >
   > Since the power transformer is 15 of the 22 pounds weight, one of my
   > thoughts was to ship that part (or an extra) ahead when traveling, and
   > when I asked was told that currently it takes about 15 minutes to
   > install, but that time might be cut.
   >
   > 73, doug
   >
   >   From: "Bob McGraw - K4TAX" <RMcGraw at Blomand.net>
   >   Date: Sun, 18 Apr 2010 16:24:43 -0500
   >
   >   Any switching supply today and one that's  "worth it's salt" should 
   > operate
   >   satisfactorily from 100 VAC to 250 VAC.   So 120 VAC or 230VAC should 
   > not be
   >   of conern.
   >
   >   73
   >   Bob, K4TAX
   >
   >
   >   ----- Original Message ----- 
   >   From: "Don Wilhelm" <w3fpr at embarqmail.com>
   >   To: "David Ferrington, M0XDF" <M0XDF at Alphadene.co.uk>
   >   Cc: <elecraft at mailman.qth.net>
   >   Sent: Friday, April 16, 2010 3:40 PM
   >   Subject: Re: [Elecraft] KPA500
   >
   >   > David,
   >   >
   >   > Because not all have hamshacks that are wired for 220 volts.  If the
   >   > space was not wired specifically for hamshack use, there is likely to 
   > be
   >   > only 120 volt receptacles available.   Up to 1000 watts draw (500 
   > watts
   >   > with 50% efficiency) on a normal 120 volt 15 amp circuit is practical,
   >   > but attempting to run more than becomes marginal.
   >   >
   >   > 73,
   >   > Don W3FPR
   >   >
   >   > David Ferrington, M0XDF wrote:
   >   >> I'm intrigued, obviously we'd look for 220v over here, but why not 
   > 120v
   >   >> in US?
   >   >> 73 de M0XDF, K3 #174
   >