[Elecraft] KPA500 Cables -- Needed for K3 ??

[Dick Dievendorff]

Richard, WB4VMH, gently informed me that the PA keying cable, the RCA key
line cable between K3 and KPA500, is supplied with the amplifier.  I
apologize! No other amplifier I've purchased came with this cable, and the
amp I have (S/N 0005) came to me without that cable early in the development
program, and I failed to check the Assembly Manual's parts list.

So the minimum you need is an RF jumper cable between K3 and amplifier, and
that can be a smallish coaxial cable.

And the KPAK3AUX cable set is still a very useful accessory.

73 de Dick, K6KR


-----Original Message-----
From: elecraft-bounces at mailman.qth.net
[mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Dick Dievendorff
Sent: Wednesday, August 10, 2011 10:29 AM
To: 'Phil Hystad'; 'elecraft at mailman.qth.net Reflector'
Subject: Re: [Elecraft] KPA500 Cables -- Needed for K3 ??

For a regular K-line K3 + P3 + KPA500 you can operate without two cables,
and the KPA500' will change bands almost immediately when a transmitted
signal is detected. I started with this configuration.

You'll need a key line cable that has an RCA phono connector on each end
(think "half of a stereo audio cable").
You'll need a short RF cable for antenna out from the K3.

Better integration with the K3 is available when you connect the K3 and
KPA500 with a 15-pin ACC cable.  Then the KPA500's band buttons will band
switch the K3, the amplifier band switches when you change bands on the K3
(without requiring a transmission) and the K3 can adjust to one of two power
levels, one for the KPA500 in operate (requiring around 25-35 watts of drive
from the K3) and another power level when the KPA500 is off or in standby
(perhaps 100 watts).  You don't have to keep fiddling with the K3 power
level if you use this option. 

The 15-pin cable incorporates the key line so the RCA key line cable is not
needed.

The KPAK3AUX cable set consists of a 15-pin cable with some pins removed, a
Y adapter, and a small "key line interrupter".

The Y adapter is useful if you have other customers for your K3's back panel
ACC connector, which is used for a lot of things like PR-6 preamplifier,
antenna switches, KRC2, FSK keying lines and the like.

The key line interrupter looks like a 9-pin "gender changer". It feeds thru
all pins except the key line and is used when you use a device (like the W2
watt meter or several other SWR bridge/wattmeters) to inhibit amplifier
keying when the SWR exceeds a threshold.  In that configuration, you connect
an RCA connection from the transceiver to the watt meter, and an RCA cable
from the watt meter to the amplifier, and you need the key line connection
inside the 15-pin ACC cable to be "interrupted".

See this document for pictures and instructions:
http://www.elecraft.com/manual/KPAK3AUX%20Cable%20Set%20Instructions.pdf

73 de Dick, K6KR


-----Original Message-----

> I have not yet bought my KPA500 but I am confused by all this talk about
cables and I admit to not paying too much attention.  But, for a regular
K-Line configuration of K3+P3+KPA500 and a future KAT500 do I need to
purchase or make any cables or is everything supplied in the boxes I would
receive from Elecraft?

73, phil, K7PEH