[Premium-Rx] Worlds First DSP-Receiver

[Rev. Harry Winter]

Connoisseurs" of "high-class" Radio receivers, to all of you

 

My name is Harry Winter and I am a retired "Member-of-Staff" with Bell Labs. (Now Lucent Technology)  I am at the present working on "upgrading" my CEI-type 232-2 receiver. --- (marketed first in 1969, shortly before CEI became part of Watkins-Johnson)

This receiver was called a "TUNABLE FILTER" by the designers and has a very low third IF of 15 or 25 KHz. No signal demodulation circuits or narrow band-pass filters are provided. Final filtering and demodulation was obviously to be done by a very powerful mini computer or even a Control-data or IBM Mainframe; --- in 1969 there was no PC, that came only in the late 70's and they were running only at a few megahertz. Maybe even the Mainframes were not fast enough at that time and a tape record of the 15 or 25 KHz had to be used instead.

 

Never-the less, ---- THIS WAS THE WORLDS FIRST DSP-RADIO! -----

 

My upgrade consists of replacing the IBM-mainframe with a DSP-chip from Analog Devices, the $12 ADSP-2184N, a TLV320AIC23 quad CODEC chip from TI and a 4 Mbit Flash chip. All this is running at 80 to 160 MIPS with lots of real-time to spare. This complete circuit, called the DSPx, is available from the ARRL for about $100 and fits into a tiny cast aluminum box of 100mm by 50 mm by 25mm (Hammond Manufacturing, Series 1590G) and has a power consumption of 250 mille Watts.--- The software is free and includes super-performance filters as well as USB, LSB, narrow FM and CW and de-noiser and auto Notch.

(See:   http://www.kk7p.com/dspx.html  ) Also, take a look at how small the DSP mainframe actually is:

        http://www.msmisp.com/futuretest/CEI-232-2-C.jpg 

It's the black-box beside the empty connector (Which is missing the AGC circuit board that needed some very minor modification.)The front panel of the CEI-232 is only 200mm wide and 80mm high, just large enough to have an IBM mainframe included.

 

That's it Paul, just upgrading a 1960 Gull wing Mercedes or E-Jaguar. 

---- Do I qualify as connoisseur? ----

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PS, I would be very interested to meet other owners of this unique "World first SD Receiver". (It's like the first swept wing Jet fighter, the ME262, --- for which now 5 newly build and upgraded versions are flying ---- cost is only $2 million each. 

 

I am also looking for a copy of the schematic for the CEI-232, it would help, but I can do without. Once I have the DSPx module fully integrated into the architecture of the CEI-2232, I will certainly share the work and circuits with the other owners of this unique receiver. Beginning in the 1990s all conventional analog receivers became obsolete --- just like the area of the "Steam-engines" for trains. 

As you might have heard though, the front-end of radio-receivers will stay analog" for many more decades, because of technology limitations. However, the DSP-part is influencing the analog part of the "architecture" of dsp-receiver designs. ---- How does the 1960 design of the CEI-232 rate for these new requirements? ---- SUPRISINGLY WELL! --- It is as if the engineers of CEI have been clairvoyant. One requirement is a very high first IF, higher than twice the highest input frequency, such a 30MHz input. First IF in the CEI-232 is 65MHz! --- If you are interested in the "receiver architecture" of dsp-receivers, read the second installment in QE on this subject. It's somewhere in the list of DSP articles below.

http://search.live.com/results.aspx?mkt=en-us&q=Signals,+Samples+and+Stuff%3A+A+DSP+Tutorial&FORM=TOOLBR 

--- More references:

http://www.arrl.org/tis/info/sdr.html

http://www.arrl.org/tis/info/pdf/98qex019.pdf 

http://www.dspguide.com/ 

http://members.aceweb.com/kd7ts/v380/man4.htm 

 

Harry