24 Sep
2005
24 Sep
'05
10:08 p.m.
Subject: Re: State of the art -radio
From: woodelf <bfranchuk at jetnet.ab.ca>
Date: Sat, 24 Sep 2005 00:25:05 -0600
To: General Discussion: On-Topic and Off-Topic Posts <cctalk at
classiccmp.org>
Well add another Crystal -- Filter that is -- :)
I agree that DSP is great for brick wall filters but you might want
to check up on Crystal Sets on the internet because I read a
few people saying that the design of the radios in the past
are based on incorrect theory.
Still wouldn't help. there are limits, Good, Fast, Cheap, Pick any two.
Non-linearity
it's bad design for some things but useful where
efficientcy counts. Look at Class E trannsmitters and switchmode
power supplies for efficientcy.
That is only because you need a sine wave out of the transmiter
something that is easy to restore with a tuned circuit. You had better
not look at what I consider a state of the art HI-Fi amp to be, the
one I built from plans I found on the web. A whole 1.25? watts RMS
per channel. I consider it state of the art because 1) It has a
regulated power supply ( Zener diode - 800 volt 6.5 amp FET pass
tranistor ) 2) Single ended ultra-linear ( 50%) operation.
A 6SL7 driver and 6V6GT for the power amp. What you
should check out is Softrock, uses the soundard and CPU
to do the back end stuff and it's frontend is a 29$ kit.
www.amqrp.org/kits/softrock40/index.html (it's sold out but the
details are there).
But is it open source? I don't like CLOSED equipment or ideas.
Some day I might want to break the glass and look inside.
Still if you have the PC it a good use for it, since it
too new to be a classic computer. :)
Maybe, today. Then again I was working with 16bit DSP
back in '81.
Allison