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Re: [linrad] Got Delta 44. Need PC.

Off topic but I was just wondering what hardware in used by
Icom, Kenwood and others in their DSP HF rigs.  They all claim
24-bit ADC.  Certainly they use a DSP chip and not a Pentium
ANyone know what's the ADC?

OK, I have some answers, see below

--- wb9uwa@xxxxxxxxxxx wrote:
> Hi All,

> I have been looking at some PC's on E-bay.
> There are thousands to chose from and it seems possible to
> find something around 500 mhz for well under $200.
> What is the minimum PC required for Linrad using a Delta 44 card?
> Is a Pentium II at 500 mhz sufficient or is a Pentium III needed?
> Is there anything special that I should watch for that might prevent
> me from using Linrad? Looking at some Delta 44 specs, it seems that
> 128mb of RAM is needed.  I would like to do this right the first
> time.

The 128MB RAM spec is for the MS Windows based software that comes
with the card.  On any machine bough today you want at least 512MB.
RAM is so cheap...

I've read on this list that you need more then 600Mhz Pentium to
handle the bandwidth of a Delta card.  Today, you can buy a
1.8Ghz Pentium for not much as the top of the line is 3Ghz.

Note a Pentium IV Gigahertz is NOT equal to a Pantium III/II
Gigahertz.  It depends on what the CPU can do in one cycle.
The new P4 has a longer pipeline the ratio of instructions
executed to clock cycles is different.  
a a 1Ghz P4 is about equal to a 800Mhz P3

> Looking at pricewatch.com, there is also some very interesting
> looking
> new PCs at around $250. Some of them say things like integrated sound
> card, integrated etc., but I suspect others may omit that detail.
> Will integrated
> things be a show stopper?

You should be able to disable the on-board sound.  Find out what
mainboard is in the PC.  Almost all the mainboard manufactures have
web sites with downloadable user manuals. Read the manual before
you buy.  If no web site and no manual find another PC.  You want
to buy one _made_ by a company that will be around next year. The
re-saller will likely be gone but that does not matter.

Lok at the type of RAM.  One bottle neck to performence is the
bandwidth between the CPU's internal cache and the system RAM.
Buy the best RAM you can afford.  (one more reason to go with
a new PC, they use more modern (faster) RAM)

 When looking for computers that need Linux
> drivers,
> what questions should I ask the PC vender and where do I do the
> search for
> the drivers?

The drivers you care about are for the sound card (Yes the Delta
is covered.) and your video card.  The only question about the video
is if the more esoteric features (for 3D graphics) are used.  
Most any card can be run as a generic VGA card.

If you know of a low cost RF quiet PC in the US that can
> do Linrad, I would love to
> hear from you. I like my Compaq Presario, as it is has a double
> sheilded case.
> It is not too hard to make it RF tight. It is a 475 mhz PC and it
> seems that they don't 
> build them like that any more. If I recall there are different RFI
> specs depending on intended
> residential use (US market)? Who has the scoop on that? I certainly
> would be ahead to get the
> right one. This is a PC that I would dedicate only to Linrad and
> nothing else.

Put the PC in another room and let the inverse square law work for

 Perhaps Linrad
> files can be transferred as needed for upgrades via a serial cable.
> Laplink could be used at
> the DOS PC end, but what would the Linux end use? Might have to put
> internet on the Linux 
> PC too. That should solve the file update problem.

A LInux/UNIX machine with no Ethernet connection is a very sad
machine.  If you have two computers you really need to install
a 100BaseT network.  Cat-5 cable is cheap and so are 100Mbit hubs.

> I realize that I can use my primary PC on a dual boot system, but I
> really want to be able to
> run other programs while on EME. I use EME loggers, do E-mail, use
> Z-track, and 
> of course I will want to use Linrad as a front end for JT44 EME.

With enough CPU power and RAM you should be able to run any number
of programs on the Linux PC at once.  I've even run MS Windows 2000
as a task on my Linux PC using VMWare (see www.vmware.com)
(It ran very well on a dual CPU system with 1GB RAM.)

Chris Albertson 
  Home:   310-376-1029  chrisalbertson90278@xxxxxxxxx
  Cell:   310-990-7550
  Office: 310-336-5189  Christopher.J.Albertson@xxxxxxxx

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