[Elecraft] K2 and the KAM XL

[ZarubaJr@aol.com]

Hi Folks,

Like a lot of Mac users, of the OS X persuasion, I had a real problem finding 
a PSK 31 solution. I was a user of MultiMode for OS 9, but I didn't like 
rebooting to OS 9 every time I wanted to play on PSK31 (it really plays havoc 
with the uptime stats ;) ).  Chris Smolinski of Black Cat Systems is working 
on a version of MultiMode for OS X, but it's not ready for prime time (yet). 
I tried LinPSK with fink and XonX, but I could never get it to work. I 
decided to bite the bullet, and try a hardware solution. Enter the KAM XL.

I've owned a boatload of Kantronics stuff over the years, so I had a pretty 
good idea what the product quality would be like. I went to HRO and managed 
to find a demo unit for about $75 off, so the price wasn't as bad as paying 
full freight, but it still wasn't cheap. I won't go into all the modes of the 
KAM XL, but it does a fine job on PACTOR, RTTY, packet.

The PSK31 implementation, is, well, uh, different. Don't get me wrong, the 
functionality is fine, and I've had quite a few QSOs on PSK31, and it works 
great with the K2. However, the user interface is weird. The way the manual 
(a pdf on a CD, not dead tree format, bummer) describes the operational flow 
is to activate the PSK31 mode and watch the "dancing bargraph." See which LED 
segment is lit, and enter CTRL-C n, where n is the number of the LED segment 
(L to R, 1 to 0). This changes the center frequency, and narrows the 
passband. Repeat this sequence until you have the signal centered in the 
display, and you should now be decoding the signal. This is counterintuitive 
in the extreme! By the time I got a signal centered, the guy was usually done 
transmitting. Fortunately, in the text display, there is a group of numbers 
which looks like this:

<700 - 1000 - 1300>

representing the low frequency cut off, the center of the pass band, and the 
high frequency cut off. I hit on a work around, whereby I select various 
CTRL-C n inputs, until I get to one centered on 1000 Hz, and with a 
reasonable passband. Then, I dial down the K2 filter to approximately the 
same bandwidth (I previously centered the K2 filters on 1000 Hz in the "r" 
mode with 700, 350 and 170 Hz bandwidths). Then I activate "fine rit" and 
start tuning around the PSK sub band. While this setup is a bit of a kludge, 
it works really well. I still have to fool around with the drive levels, 
since I've been running a IMD of -18 to -20 db. When I had the K2 over at a 
friends house, we used DigiPan on his PC and with proper adjustment, I was 
seeing IMD readings in the neighborhood of -25 db.

The downside to this kludgy setup happens when you jump out of PSK mode, then 
back in. Nothing done previously get set in EEPROM or NVRAM, so you have to 
go through the evolution again. I'm getting pretty quick with it, my setup 
time is well under a minute. I wrote an e-mail to Kantronics (copies to sales 
and service) wherein I suggested changing the PSK31 submenu so the you could 
set the center frequency and passband in the main menu, like all the other 
parameters (and have them remembered). Then PSK31 operating would be a snap. 
I was pleasantly surprised to get a response from the VP of sales saying that 
my idea was being forwarded to engineering for evaluation. Since the KAM XL 
has flash firmware, hopefully it wouldn't be too much of a headache to change 
the code and have it available for download from their web site. I was pretty 
happy with Kantronics customer response (but if they were in Elecrafts 
league, the change would be out by now!)

I hope this missive has been helpful, and I have a request. If anyone on the 
list has any experience with the AOR Telereader (which also does stand alone 
PSK) console, please consider writing a user evaluation. I was also looking 
at that unit, but the Telereader wasn't in stock, and the XL was. I'd like to 
know if I goofed due to being impatient (again).

73,

John AA2BN
K2 #1912