[Elecraft] Enhancements for SO2R (was KPA 1500 - SO2R)

[Randy Farmer]

I'm changing the topic to more accurately reflect the ongoing discussion.

I'm also using a KAT500 on each of my two K-lines in my SO2R station, 
and I too would appreciate a bit more "intelligence" in the KAT500. My 
fully automated antenna switching arrangement uses a microHAM Double Ten 
switch, with the control for the two radio ports coming from a Station 
Master on each radio, so there are only two feedlines that enter the 
radio room.The antenna switching hardware is concealed in the attic on 
the other side of the wall from the station. Like everyone else who has 
attempted to set up a SO2R station using multiband antennas, I've 
grappled with the problem that the design of all the currently available 
switching and control hardware explicitly assumes you have separate 
antennas for each band. For many of us, this just isn't true.

I mainly use the KAT500 as a line flattener for my 160, 80 and 40 meter 
antennas; no problem there. But.. I also have a 20-15-10 dipole that I 
use for the second radio on the high bands. The dipole is pretty low and 
isn't particularly well matched, especially on 15 and 10. I now have the 
KAT500 on the secondary radio set up to match the dipole on 20 through 
10. However, if I'm running SO2R with the primary radio on 40 and the 
secondary radio on 20 then I'll normally switch my SteppIR to the 
secondary radio, meaning I have to remember to put the KAT500 in bypass, 
and then to change it back later. Sometimes I don't. (Mother Nature and 
Father Time, you know.)

Even in SO1R mode, I sometimes want to quickly switch to the dipole on 
the high bands if someone calls me well out of the beam's main lobe. The 
Station Master makes the actual switching very easy via a keypad on the 
desk, but in this case I end up with the radio looking into a fairly 
high VSWR antenna if I don't also manually put the KAT500 in bypass 
mode. This isn't so good, especially if I'm running the KPA500.

What would be REALLY NICE would be if there were some way for the KAT500 
to know which ANTENNA has been selected, and switch in the appropriate 
matching solution for that antenna on that band. I don't see any way to 
do this, given the present architecture. If there were some additional 
communication channel between the station control hardware and the 
KAT500 (and other Elecraft products) such as an extended command over 
the RS232 link in the case of the KAT500 or over the USB link for the 
KPA1500, conveying both band information and antenna ID could 
potentially be done. A simple 4 bit band code wouldn't be sufficient, 
but perhaps an 8 bit word with 4 bits of band information and 4 bits of 
antenna number would work. Of course, there then remains the 
not-so-small matter of formatting and transmitting this information 
packet from a wide variety of station control architectures using 
hardware from a number of vendors. Perhaps if Elecraft were to pave the 
way by implementing this capability the makers of the various commercial 
controllers would be willing to code in support for the feature. Just 
thinking out loud, and wishing...

73...
Randy, W8FN


On 4/25/2017 10:11 PM, Bob wrote:
> Hi Bill,
>
>        No XYL requests involved but in a similar manner I have reduced 
> the feed lines into the shack.  I have a remote antenna switch system 
> consisting of an Array Solutions Rat Pack with the Ten Tec interface 
> box.  This is under control of an Elecraft KRC2 unit.  It saves many 
> feet of coax and reduces the in shack cable clutter.
>
>        Station is K3, KPA500 and KAT500 and more Elecraft with K2 and 
> KX3. My issue is I'm not getting full value from the KAT500. It is 
> capable of switching 3 antennas.  But with a single feed line on 
> position one all else is lost.  So my request would be to be able 
> select alternative programmed values by using the KAT 500 antenna 
> switch. Any manually selected antenna would apply tuner values to the 
> antenna position but ANT 1 would remain selected. As it is now it 
> works but requires retuning when manually changing between selected, 
> say, 80 meter antennas and prior values are lost. In hardware I could 
> do it now but don't want to butcher the KAT500.
>
>        Well beyond my pay grade as I do not know how much 
> reprogramming would be required in the firmware and utility to select 
> this as an option.
>
>         This option could possibly be done in the KPA1500 too. 
> Certainly be a plus in consideration of the KPA1500  which seems to 
> have less in that there are only 2 antenna selections available.
>
> 73,
> Bob
> K2TK  ex KN2TKR (1956) and K2TKR
>
>
>
> On 4/25/2017 4:14 PM, Bill Frantz wrote:
>> My most wonderful and understanding wife has requested that the 
>> number of
>> "wires" coming into the house be minimized. To accommodate her 
>> wishes, I have an
>> external antenna switch. It would be very nice if all the Elecraft 
>> tuners could
>> take an externally provided antenna ID to use to recall the antenna 
>> tuning
>> parameters. A 4 bit "band ID" would be ideal, but a command over the 
>> RS-232
>> interface would also work.
>>
>> 73 Bill AE6JV
>>
>> On 4/25/17 at 7:50 AM, n6kr at elecraft.com (Wayne Burdick) wrote:
>>
>>> KPA1500 firmware will be updated to fully support such products as 
>>> we identify
>>> them. We oversized the microcontroller memory by a factor of about 8 
>>> to allow
>>> for such expansion. In addition to SO2R, there may be other gear 
>>> such as
>>> antenna switches that we can directly control from the amp’s antenna 
>>> and ATU
>>> switches, and status can be shown on the 32-character LCD.
>>
>> ------------------------------------------------------------------------- 
>>
>> Bill Frantz        | Airline peanut bag: "Produced  | Periwinkle
>> (408)356-8506      | in a facility that processes   | 16345 Englewood 
>> Ave
>> www.pwpconsult.com | peanuts and other nuts." - Duh | Los Gatos, CA 95032