[Elecraft] Externmal ATU

[Joe Subich, W4TV]

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
>
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