Wow, wasn?t expecting this to turn into a reverse
engineering exercise but here?s a bit more from me.
For what it?s worth though I suspect little if any of
the actual circuits of the RX-340, Pegasus etc will be
directly incorporated into the main RX of the Orion.
Scott even said so by describing it as a completely
new design. Nevertheless I believe that we'll
ultimately see considerable design similarities using
a newer more powerful generation of core IC?s.
Additional comments in-line below preceeded with
"N9DG:".
--- Jim Reid <jimr.reid@verizon.net> wrote:
The RX-340 manual lists manufacturer's part numbers
for
the D/A and A/D converters, surface mount IC's, but
not a manufacturer's name. Part numbers are:
A/D on boaard 81790, AD7872JN
D/A, same board, AD7840JN .
Does this info tell us anything about the dynamic
range
of these devices in the 340, if you can ID the
manufacturer?
N9DG:
These are Analog Devices part numbers, for more
information about them see:
http://products.analog.com/products/buildButtons.asp?product=AD7872
http://products.analog.com/products/buildButtons.asp?product=AD7840
I can?t really offer any definitive comments about the
dynamic range of these devices in and of themselves.
However based on the data from the two links above it
looks to me that the much of the overall dynamic range
performance of the RX-340 is established well before
the A/D-DSP work even begins. As I?m sure is the case
for the other TT IF DSP radios as well.
--- Jim Reid <jimr.reid@verizon.net> wrote:
The synthesizer chip in the 340 is Motorola part
MC145170D1; is this the same as the Pegasus/K2?
N9DG:
Probably not exactly the same but is indeed a very
close relative, on the K2 schematic it is listed
simply as a MC145170. Admittedly I?m not 100% sure
about the Pegasus/Jupiter (don?t have a schematic and
I didn?t really want to take it that far apart to look
either :-) ) but the both the RX-320 and RX-350 also
use the MC145170 series PLL chip. So I think it would
be a pretty safe bet that the Pegasus/Jupiter do too.
--- Jim Reid <jimr.reid@verizon.net> wrote:
The first LO in the 340 is a three loop architecture
synthesizer. There are two 10 MHz TCVCXO crystals
on this board (81772). They have manufacturer's
part numbers of VTXO14010G and the other
DFA20-HAV10MHZA1 if these part numbers will shed
any more light on what is going on, hi.
N9DG:
No doubt the actual crystal oscillators do play a
sizeable role in the phase noise performance. I didn?t
actually look for any data on these parts, have no
previous frame of reference to draw any kind of
conclusions though, ... ok so I'm being lazy.
Duane
N9DG
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