[Elecraft] K3/HL-1.2Kfx

[Bob Cunnings]

> Lyle never said that.  Someone was quoting my response and had my name
> at the top followed by their assertion, and my comments a few paragraphs
> down.

Sorry about the wrongly attributing  that remark to you, Lyle.

Yes, I understand the case where ALC is mis-applied as a form of drive
control, it's been frequently discussed here. It was the "last ditch"
amplifier protection case mentioned by W5OV in an earlier message that
to my mind seemed possible and maybe even recommended in the case of
the K3/KPA500 system. That's why I asked - I wondered if the KPA500
will provide ALC output and if the amp protection case would be
supported. Since it will be, and seems a desirable equipment safety
feature, I'll plan on updating my older K3s to be compatible. It's
easy nowadays with the availability of the REMIOUPGD KIO3 replacement
boards.

Bob NW8L


On Sun, Jul 4, 2010 at 12:41 PM, Lyle Johnson <kk7p at wavecable.com> wrote:
>
>> I'm curious as to whether or not Lyle's assertion "The K3 does have
>> ALC output, but you shouldn't use it."
>
> Lyle never said that.  Someone was quoting my response and had my name
> at the top followed by their assertion, and my comments a few paragraphs
> down.
>
> In fact, the K3 has ALC *input* that is compatible with most amplifiers,
> assuming the K3 has the negative ALC mod.  The negative ALC has been
> standard in production for the K3 for many, many months now.
>
> In general, I suggest you set the K3 to run the amplifier at its normal
> level, and have ALC connected in case something goes mildly wrong and
> the amplifier requests drive be reduced , but before the amplifier
> faults and goes off-line.  One should never crank up the
> transmitter/exciter to the amplifier, and then use ALC to throttle back
> the drive as this usually  leads to splatter and other undesirable traits.
>
> The ALC has not yet been activated in the KPA500, but will be soon.  My
> prototype KPA500 is operating nicely on the air with today's KPA500
> firmware update :-) . I set the drive from the K3 to get about 450W to
> 500W on peaks. The amplifier is good to well over 600 watts, so that
> leaves plenty of margin, better IMD, etc.
>
> 73,
>
> Lyle KK7P