[Ham-Mac] Re: Ham-Mac digest, Vol 4 #189 - 3 msgs

Wed, 12 Nov 2003 11:38:57 -0500

John,

I'm the guy with the rf mac transmit crash problem... well i started 
this thread anyway... it just occured to me while reading your 
comments, which i appreciate - the g4 tower has a PUSH button for 
power/sleep/shutdown... but the flat panel has one of the 
"touch-sensitive" buttons for power/sleep/shutdown AND one for 
brightness... AND it occurs to me that sometimes the mac sleeps, 
sometimes it crashes... BUT sometimes the brightness control panel 
comes up on the screen....

perhaps this is the whole problem.... those "touch-sensitive" buttons 
could be taking in the rf and freaking out... remember the original Mac 
CUBE's? those power buttons were WILD with errors and freakouts without 
even being touched... they were called proximity switches and mine had 
to be replaced four times...

wonder if there is a way to "de-commission" those two buttons on the 
flat panel.. hmmm

walter

On Nov 12, 2003, at 04:04, John Townend <[email protected]> 
wrote:

>
>
> --__--__--
>
> Message: 1
> Date: Tue, 11 Nov 2003 18:50:10 +0000
> From: John Townend <[email protected]>
> To: [email protected]
> Subject: [Ham-Mac] Mac crashes on transmit or tune
> Reply-To: [email protected]
>
> It would seem that the power switching on Macs is very prone to strong
> RF fields. I assume it is some form of remote semiconductor power
> switching within the Mac. My G3 iMac would auto switch on when
> transmitting above 10 MHz which was not a great problem as I run Hamlog
> anyway. My stack of 4 coax feeds pass within 6 inches of the computer
> so it was not unexpected.  The G3 has been replaced by a G4 flat screen
> iMac in its fancy plastic case and there are no problems in either
> direction. For the unfortunates it is a trial and error  situation -
> move cables around, lots of ferrite beads and get the stray RF down to
> a minimum
> I would be interested if anyone knows how the power switching works on
> the Macs and is there some form of sequential switching to cope with
> varying loads at boot up or shut down.  What do AppleMac say about it -
> there must be users other than amateurs who use Macs in RF fields.
>
> John G3BBD/N3YZR
>