Xref: utzoo rec.ham-radio:13397 sci.electronics:7880
Path: utzoo!attcan!utgpu!watmath!att!tut.cis.ohio-state.edu!gem.mps.ohio-state.edu!wuarchive!mailrus!ncar!asuvax!anasaz!john
From: john@anasaz.UUCP (John Moore)
Newsgroups: rec.ham-radio,sci.electronics
Subject: Re: New cheap 200 kHz ADC: good for digital receiver?
Message-ID: <734@anasaz.UUCP>
Date: 21 Sep 89 13:51:54 GMT
References: <1989Sep19.171259.1670@mentor.com> <17673@bellcore.bellcore.com>
Reply-To: john@anasaz.UUCP (John Moore)
Followup-To: rec.ham-radio
Organization: Anasazi Inc, Phoenix AZ
Lines: 20

In article <17673@bellcore.bellcore.com> karn@jupiter.bellcore.com (Phil R. Karn) writes:
]>  Antenna ---> Mixer ---> LPF/gain --> ADC -----> DSP -----> DAC -----> audio
]>                 ^                                |
]>                 |                                |
]>              DDSynth                             \------> data
]>
]>A few real RF stages + cheap digital VLSI = high-performance receiver?
]
]Actually, you'll want two mixers, low pass filters and A/D converters.
]The mixers should operate in quadrature so you can do things like SSB
]filtering in DSP software.

I don't think so. You should be able to do that in the DSP with a single
ADC. After all, the signal into the ADC is identical to that off the
antenna except that it has a lower carrier frequency.
-- 
John Moore (NJ7E)           mcdphx!anasaz!john asuvax!anasaz!john
(602) 861-7607 (day or eve) long palladium, short petroleum
7525 Clearwater Pkwy, Scottsdale, AZ 85253
The 2nd amendment is about military weapons, NOT JUST hunting weapons!