[Elecraft] Externmal ATU

[Lu Romero]

I would LOVE to have a Kenwood-AT300-Like press of the ANT
TUNE button on the K3 panel  to start an automatic tune
cycle on my K3/ALS600/MFJ998 combo.  That would be perfect!

My TUNE POWER is set to 10w.  This makes between 40 to 60w
on the ALS600.  Using the TUNE press and hold method, the
tuner sort of "snaps" the needed values in in less than a
second, everywhere I go.  Again, I have taught the tuner my
antennas and memorized them into the tuner memory ahead of
time.  The amp is interupted, the tuner tunes, then the amp
is re-enabled, and the power then goes up from 10w to the
above values.  The red light on the amp sort of blinks.  

Interesting that Phil's '998 takes a while to figure things
out.

I bought my ALS600/MFJ998 combo after reading Phil's review
of the system... Could it be a '998 firmware thing?

-lu-w4lt- 

Message: 15
Date: Thu, 26 Aug 2010 17:07:12 -0400
From: "Joe Subich, W4TV" <lists at subich.com>
Subject: Re: [Elecraft] Externmal ATU
To: elecraft at mailman.qth.net, dpsalas at tx.rr.com
Message-ID: <4C76D780.6000306 at subich.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed


Phil,

 > If the K3 took in a remote TUNE request, then I would not
have to
 > remember to manually take the ALS-600 off-line.

The problem is that the lack of external I/O to accommodate
a remote
TUNE request or provide a tune command (e.g., Icom "Start"
signal).
It will take some fancy programming - and overloading some
of the
existing I/O perhaps with outboard decoding - to accommodate
external
tuner control.

73,

    ... Joe, W4TV

On 8/25/2010 6:43 AM, Phil & Debbie Salas wrote:
> "Phil, I am not certain if you or someone else originally
asked the
> question -
> but -- The K3 can provide a lower power RF source for
tuning.
> As others have mentioned - first set the Tune power in the
menu.
> Then use TUNE (not ATU TUNE)  and the K3 will transmit at
the power you
> set in the menu."
>
> Don - Yes, I have my TUNE power set for 15 watts (this
gives excellant
> accuracy with the MFJ-998, and is running the K3 PA at
pretty much minimum
> power during the tune process).  I was commenting on your
comment to use the
> keying input to tune the radio with a straght key.  I
currently hit TUNE on
> the K3 to start the MFJ-998 tuning process (MFJ-998 is set
for full auto and
> begins tuning when SWR>  2:1).  And while the MFJ-998
disables the amp-key
> line during tuning, unless I remember to turn the amp to
standby first,
> there are a few milliseconds when the amp may be looking
at a high SWR
> before the MFJ-998 "realizes" the SWR is high, interrupts
the amp-key
line,
> and tunes.  My ALS-600 has about 10dB of gain, so with a
15 watt TUNE drive
> level I get around 150 watts out.  However, a K3 remote
input request for
> TUNE would eliminate this problem.  When you press the
TUNE button on the
> MFJ-998 it first interrupts the amp-key line, sends a TUNE
request to your
> transceiver (not currently implemented in the K3, but is
in many other
> transceivers), tunes, disables the TUNE request, and then
re-enables the
> amp-key line.  Normally my ALS-600 doesn't trip out if I
forget to switch it
> to standby before pressing TUNE on the K3, but
occasionally it does.  If the
> K3 took in a remote TUNE request, then I would not have to
remember to
> manually take the ALS-600 off-line.
>
> Phil - AD5X