[50mhz] Re: [Remotebase] PC based controllers

[cboone@earthlink.net]

Dave,
PC based rptr controllers have been done before... (the C64 model
and the PCRC come to mind)...problems arise when doing this though:

1) A PC requires 110V AC....since the power supply does +12 +5 and -5.
Dedicated controllers run on +12 only because of the internal power
supply which supplies the 5 and -5 to the board
2) The RF noise from a PC is much worse than from a good quality
rptr controller built for that purpose
3) The size of a PC vs a dedicated single board controller...well
we know about that all too easy! :)
4) A dedicated controller is usually RF proof (it BETTER be!)...PCs
are usually NOT.
5) Most rptr controllers use machine language (faster than DOS
and for sure Windows!) or similar (C++, etc)...this allows the
programming to be done in smaller memory and not have a "System" OS
take up space....This form of programming is NOT for the faint of
heart (I bow down to those who know it well!)..this keeps the
parts count LOW and the size of the system board (which has the
audio gating, etc on it) to a minimum..

NOW with all that in mind, IT'S possible to do your own rptr controller
but is it worth the time?? Thats the big issue...how much is your TIME
WORTH to you? AT one time several friends and myself investigated such
a project.....when Link came out with their stuff, we gave up...

Now if you have the people who can do it, go for it....
I know of a few homebrew controllers done from PCs...but they are not
plentiful and can cause many hours of grief trying to debug and
correct the programming...plus the hours spent modifying the box
for rptr use...(remember lightning protection, etc!!)
Yes you can use a sound card for audio....get a GOOD quality one with
no hiss out of it...PLUS you may want to filter the output because
we are dealing only with 3-4 kHz max audio b/w...not 15-20 kHz!!!
Interfacing to the outside world is going to be the worse problem...

Ya know, you MIGHT want to look at the old 73 article "The Talking
Rptr Controller" back in the early to mid 80s....This article
shows the complexity of programming in machine language (if you
decide to go that way)..and was the basis for the RC 850 controller
(Ed WA6AXX himself is the author! :)

Whichever route you choose will be your decision.....good luck in
whatever your choice is....and let us know what you decide!

Chris
WB5ITT

Dave Stephens wrote:
> 
> Hello all,
> 
> Ok i got a good one for you all. i have played a bit with echo station (
> a PC based repeater controller), and it sparked an idea. the echo
> station is kinda neat BUT it doesnt do what i want. now here are the
> questions i have for all you brains that have knowledge in these fields:
> 
> Computer programing
> Repeater controllers
> 
> so here we go with the questions.
> 
> 1. i am sure that it is hard for someone that doesnt know anything about
> designing and writing computer programs (me) but, how extencive is the
> programing for something like Echo Station? i mean is this a very
> extencive program or is it a realitivly simple program?