[Ham-Mac] Re USB Interfaces for Ham Radio

[Jim or Sue]

>Jan-Henrik Preine <Jan-Henrik.Preine@ik.fh-hannover.de> wrote:
>---
>>K6VKV@aol.com wrote:
>>
>>>  I too have the problem of USB devices dropping off line.  In my 
>>>case, I have
>>>  two USB zip drives that vanish from the desktop when mounted.  One is
>>>  connected via a Belkin USB hub, the other is via a SCSI interface adaptor
>>>  (also Belkin) plugged into the Belkin hub.
>>>
>>>  When this happens, the Belkin devices' lights go out.  Belkin has never
>>>  enlightened me as to the meaning of the lights.
>>>
>>>  My computer is a 400 MHz iMac DVD SE.  Also on my USB hub is a floppy drive
>>>  and an Epson scanner.  System is 9.0.4.
>>>
>>>  I would appreciate any enlightenment.
>>>
>>>  John Mason  K6VKV
>>>  Morro Bay California
>>>  _______________________________________________
>>>  http://mailman.qth.net/mailman/listinfo/ham-mac
>>>
>>
>>It happened to me quite often on several PowerMacs and iMacs. I had to
>>unplug and plug the hub to get the devices recognized again. I used the
>>Energy Saver Control Panel set to never go to sleep but dimm the screen and
>>now it happens quite seldom.
>
>This is not only a mac-problem. The same hapens on my notebook which 
>is connected to my inhouse network with a usb -> 10baseT adaptor. 
>When the comp falls into the energy save mode it drops the 
>connection to the net. Unplugging and reconnecing the usb helps...
>
>Bye...     dg3mgw  Udo
>_______________________________________________
>Ham-Mac mailing list
>Ham-Mac@mailman.qth.net
>http://mailman.qth.net/mailman/listinfo/ham-mac
=============================================

I have an Asante 4 port USB hub and had some problems with it similar 
to those indicated above.
In calling Asante technical support I learned that the two USB ports 
on the Mac do not support equal loads. USB port #1 is a low current 
port and is for the keyboard and mouse ONLY.  Do not plug any other 
USB devices in the other port on the keyboard either! The two ports 
on the keyboard are for the mouse and are located so either left or 
right handed persons can plug in the mouse on the appropriate side. 
You can also plug in a security "dongle" into the second keyboard 
port if one is used, however.

The #2 USB port on the back of the computer (or wherever it is 
located on the iMac) is the high current USB port. This is where you 
connect your hub. There is another caveat though. If you over load 
this port it will work erratically. If you have several devices such 
as a Palm Pilot cradle, a floppy drive, a printer, a Zip drive or 
CDR-W drive or any combination of these, you will certainly need a 
USB hub that is SELF POWERED. The self powered hubs usually have a 
wall wort type power supply which provides more current to run the 
USB ports on the peripherals you may plug into the hub.

All this said, I have found there is still no magic bullet that 
guarantees absolute USB port stability but following these guidelines 
help.

Jim, N9NGH
EN-34px Hudson, WI