[Elecraft] Multiple KUSB Connects

[David Ahrendts]

My friends, thank you for your many responses to this question. Clearly I’m not the only one thinking of multiple semi-permnanent KUSB connections to multiple Elecraft devices simultaneously. Lesson: all things are not equal when you select a USB powered hub. 

Among the responses that I found most valuable was this one sent directly from N1HO, Bayard R. “Brandy” Coolidge — much thought has been put into his USB to Mac setup — sharing it here with everyone:


I just upgraded my shack from an Acer Netbook (1.66 GHz 32-bit,
2GB memory) to an early 2015 Macbook Pro Retina 13" at 2.7GHz
with 16GB memory (and 250GB of SSD). I had used a powered USB hub
from an "office superstore" that ran at USB 2.0 speeds, and had
Sabrent USB/serial cables (which explicitly use FTDI chips) running
to the K3 command port, the KPC 3+ (which went to another rig for
VHF packet use), the Trimble Thunderbolt GPSDO's NMEA port, plus
the SignaLink USB's cable.

When I upgraded to the Mac, I also shucked the old USB hub in favor
of a Sabrent 4-port USB3 hub. I'm running Windows 7 Home Premium under
Parallels 10, and the Mac is running Yosemite with all the latest updates.
(The Acer Netbook ran Windows 7 Starter). I've had this setup running
for a couple of weeks now, and I'm extremely pleased. In fact, just
yesterday I swapped out the SignaLink for an Asus Xonar U5 sound card,
which Jim, K9YC recommended on the list - it works perfectly. Last night, I
was able to take the rMBP, an old Alinco handheld, the KPC3+, the
special cable to run from the Alinco to the KPC3+ and one of the USB
cables with me to an ARES meeting. It all plugged in and played WITHOUT
having to fuss with COM port designations, etc., etc. Came home, spent
5 minutes (maybe) reconnecting everything and all came up smiling.

That said, I don't quite know what to tell you except that one thing
that helped maintain some sanity with my old hardware configuration
was to mark each and every cable and every USB hub port and never, ever
plug them in "wrong". Otherwise, Windows would go off and assign a new
COM port number to a given cable and I'd end up chasing my tail. I'm a
retired UNIX software QC engineer, so my tolerance for that sort of
baloney is minimal. One thing that bit me frequently, and took me months
to finally nail down, was that for whatever reason, Windows would insist
on spontaneously downloading, installing, and running a Ballpoint Pen
device driver for the Thunderbolt, basically taking over for the mouse,
resulting in all kinds of cursor movement and "clicks". I had to figure
out how to outfox it, get into Device Manager and disable that driver.
I later found a brief discussion on the Time-Nuts mailing list about it,
and a few other guys had had the same problem and disabling under DM was
apparently the only viable solution. (The Thunderbolt runs at 4800 baud).

That said, I've been amazed that I was able to pull everything last night,
go to the meeting with just the KPC3+ and then reassemble perfectly. Since
you're going to be dealing with multiple K3s, and will probably want to
run them both/all at 38400, you may go nuts trying to figure out which is
which. Remember that the K3 Utility does display the serial number in the
title bar, and you'll need to assign a different COM port for each rig,
so I think some patient labelling and record keeping could help there. I
rarely run the Utility anyway - only long enough to download and install
firmware - so I don't (personally) see the need to run two copies
simultaneously. However, you will need to figure out how/where to store
the configuration files for each rig separately; I can't remember what the
normal default file locations are offhand. But it should be possible to
bring up the Utility and manually change its COM port so that it's talking
to Rig B instead of Rig A. (Or there may be a configuration file for the
Utility as well, so that it knows what COM port, etc. to use or it may be
possible to invoke a specific COM port on the command line, in which case
you could create two desktop shortcuts, one pointing to one rig's COM port,
the other to the other - Lady Heather, the control program for the GPSDO
does that, as do many other applications). BTW, under Parallels, you can
force it to grab the various ports, including the external "sound card",
away from OS X and assign them quasi-permanently to Windows, so that Windows
will always be able to drive those devices.

Again, I'm NOT a Windows expert, but I do hope that this provides some clues,
and if you have further questions, please feel free to e-mail me, and I'll
try to help.

Very 73,

Bayard R. "Brandy" Coolidge, N1HO


David Ahrendts   davidahrendts at me.com