[Ham-Computers] RE: RF quiet computers

Thu Nov 29 18:53:41 EST 2007

Planet Earth, AKA third rock from the Sun, to Aaron "Mr. CPU" Hsu. Did you 
receive the e-mail, and/or the voice mail message, concerning the possible 
hard drive failure of my faithful Compaq Prosario 233 MHZ P1 machine with 
30,000+ hours on it? If that machine dies before I have a MS DOS capable 
backup machine configured and functional, I will also die! Since I depend on 
that machine to execute all the personal custom designed software that I 
wrote in the early to late eighties to perform the daily tasks I need done, 
and none of the computers since MS Windows 98 SE was buried and Windows 2K 
was born will run any of the software I depend on to survive, you need to 
wave your hands and heal this helper of the handicapped!

It is "NOT" as easy as most of you are thinking right now! What you don't 
know: almost all of the aids, appliances and adaptive technology to make the 
lives of the handicapped easier, more productive, possible and independent 
cost more money then you would believe!

Would you purchase a new computer for $900 with a 17 inch flat panel display 
included? Maybe even a color scanner or printer as a free bonus, maybe even 
both.

Now how about spending another $895 for the software program that reads the 
CRT display and converts it into a form that can be spoken via a speech 
synthesizer? Then add another $600+ for an external speech synthesizer so 
you can hear your $895 screen reading program talk? (Yes. You could use the 
internal sound chip, or card, but in doing so you invite all sorts of wave 
file and other memory allocation issues. Such as no Windows sounds etc. You 
have no memory issues with an external synthesizer!). Now you have spent an 
additional $1495 to make your $900 computer talk!

But wait! How about scanning text so you can read a piece of regular mail, a 
page out of a book, a newspaper, a magazine article etc.? Now that is 
another $1,400 aprox. More special software and a black and white flat bed 
scanner is needed. Now that computer is costing you $2895!

Because you are sighted, it is not an issue. But if you were blind, you have 
no choice. Pay it or go without a computer.

Ask yourself honestly if you would be willing to pay $3795 just to use a 
computer?

Duane Fischer, W8DBF/WPE8CXO
dfischer at usol.com
HHI: Halligan's Hallicrafters International
http://www.w9wze.net
HHRP: Historic Halligan Radio Project
hhrp.w9wze.net

----- Original Message ----- 
From: "Hsu, Aaron (NBC Universal)" <aaron.hsu at nbcuni.com>
To: <dx-list at yahoogroups.com>; <cq-contest at contesting.com>; 
<ft-100 at yahoogroups.com>; <icom at mailman.qth.net>; <yaesu at mailman.qth.net>; 
<yaesu at contesting.com>; "I>Ham-Computers" <Ham-Computers at mailman.qth.net>
Sent: Thursday, November 29, 2007 6:04 PM
Subject: [Ham-Computers] RE: RF quiet computers

> John,
>
> The PC's switching power supply is a major contributor to RFI from a 
> computer.  Many cheap "lightweight" supplies have few or even lack any 
> type of input or output filtering.  First thing I would do is replace the 
> power supply with a better quality one (or take it apart and start adding 
> bypass caps and chokes).  Not all power supplies are built the same.  I 
> prefer PC Power and Cooling supplies (http://www.pcpowercooling.com)- well 
> built and they don't skimp on engineering.  Good alternatives are Antec's 
> "True Power" or "NeoHE" series and higher-end Seasonic supplies, but I 
> haven't done much RFI testing on either.  I use various PCPC and Antec 
> supplies in my computers at home and don't notice much RFI, but I live in 
> a suburb of Los Angeles (6 miles from Downtown), so local PC generated 
> hash is minor compared to all the other crap from the city <g>.  My 
> laptop's power brick usually causes more RF hash than the other PC's 
> combined.
>
> Another thing to do is make sure you have a well shielded case (lots of 
> sheet metal with good connectivity).  Also make sure that *ALL* cables 
> comming out of the PC have an RF choke attached as close to the PC as 
> possible (and better if also at the other end) - snap-on chokes often work 
> OK.  UTP ethernet cables may be an exception as the chokes may hamper 
> performance - test before and after attaching chokes.  UTP is balanced 
> anyway, so it shouldn't radiate much.
>
> 73,
>
>  - Aaron Hsu, NN6O
>
>
> -----Original Message-----
> Sent: Thursday, November 29, 2007 9:37 AM
> Subject: [Yaesu] RF quiet computers
>
> Recently, I discovered how RF noisy my fairly recent
> ebay purchased laptop is (an Acer Pentium III).  It
> replaced a Micron Pentium 120mhz computer which was
> very quiet on the radio, but also kind of slow, and I
> thought a laptop would be nice in the shack because it
> would mean less wires, etc.
>
> I find that it really raises the noise floor on 80,
> somewhat on 40, and on parts of 20 and 15.  It is
> probably bad on other bands as well, but I really
> haven't experimented with them yet.
>
> So I probably need to get a replacement, unless anyone
> knows how to kill this noise. What are some good, RF
> quiet computers to look at? I don't have alot of money
> to spend, but can come up with a little bit.  Speed
> probably won't be that important, as long as I can use
> it for some of the digital modes.  The Micron
> unfortunately died, or I would hook it back up.
>
> 73s John AA5JG
>
>
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