Gang,
Quick status report on the Pixie, a.k.a. Super Pixie 40.
1. Since everyone liked the schematic on the web, we'll do the next
one that way.
2. I delayed putting up the W1FB version since I found that I didn't
like the waveforms present. I did better with some experimenting
and research. Doug's is fine and works, so this is not a critique
of his work.
3. So have prototyped a new version, thus the name Super Pixie 40, and
working on a writeup.
At the suggestion of Doug Hendricks, KI6DS, I am in the process of doing
several things on this one. a) A step by step writeup of each section,
b) a step by step assembly and checkout, with and without certain lab
equipment, c) schematics in .jpg, .gif, and PostScript (tm) formats,
d) all info from web page, ftp site, and in ASCII format or PostScript
except for the schematics which I refuse to do in ASCII, :-) and
complete writeup in QRPp for those that don't have internet capability
or don't want it, and THE prototype at Dayton for sure. What we are
shooting for here is the first complete Internet QRP Rig, i.e. one that you
can get everything from the internet except actually picking up the parts,
but that could happen too.
Now there are two ways to go on this:
1. Smallest number of parts and low initial costs or
2. larger parts count and nicer characteristics. I opted for door number 2.
My choice. Next one may/will/should go for SuperHet instead of DC receiver.
In fact, talking about receivers. The pixie doesn't have and is not
expected to have all that great a receiver. So the question is, how well
can you do a superhet with a small number of parts. The smallest one that
I know of is from MXM in Smithville TX, the SimpleRX and costs around
$50. But it has a 455KHz filter that you can't find just anywhere that
I know of. I think for a simple 40M or 30M XCVR under $50 with superhet
receiver I have to give the first prize to Dave Benson, NN1G, for the
NE4040 and NE4030. (I guess it was one of or the first XCVR club projects
in the USofA. I may be wrong here since so much has happened in the last four
years.)
There are many NN1G NE4040s around and we aren't even counting the Mark I
and Mark II and Mark III........ in the long line. ;-) You can still get
the boards (2) from FAR for $9 for the Mark series and the NE4040
(QST Nov 94) board for $6.
The SP40 will have an order form for Mouser, so that all the parts
except the LM386 (Radio Shack), crystal (KI6DS), and the PC board (FAR) can
be gotten from one place. I'll also know by Monday if Anchor Electronics in
Santa Clara CA will be able to supply the parts from one place. I think they
can and they do mail order. I always make them the last stop on the way out
of CA on business trips. They have taken a lot of my money and didn't ask for
an ID either. :-) The only place in the USofA that I know of where you
can walk in and pick up any TenTec case off the shelf. So I don't get
too much email on this one: Anchor Electronics, 2040 Walsh Ave., Santa Clara,
CA 95050 (408) 727-3693 and fax at (408) 727-4424 and they take Visa,
American Express, and MasterCard. They have lots of SMT stuff too. If
you are flying into or out of San Jose they are within a few miles of
the airport.
Features of the Super Pixie 40 (subject to change):
o DC receiver
o 700 Hz offset between transmit and receive
o VXO (don't have the final range yet)
o 700 Hz audio filter
o Guessing at 1W output, but that's still up in the air
No 5W mod onboard.
o Sidetone from Jeff in QRPp
o Off board connections on the edge like Ori's NC38S
o 40M only as 30M version would be deaf or nearly so
o single sided PC board
o 7.040 or 7.112 crystals
PC board layout later so not sized yet and I won't be aiming for the
Altoids only size. :-) ;-) Will ask anyone that has the PC board
layout software to come forward and help on this one. You'll get
credit for doing this but there is no profit involved, just fame.
So everyone that's interested, hold onto your horses. If you have
ever designed and played with circuits you know how much time this
takes. I am methodical and and I can't tell you how many themes and
variations I went through to get a nice sine wave just out of the
oscillator section alone. A bunch. :-) This is not an overnight
wonder project. A week, maybe, and I'm going way out on a limb just
doing this much. Kinda like standing on a ledge and seeing a large
crowd watching. ;-) It is scarey.
OK, back to your regularly scheduled programming. Film at 11.
Chuck Adams K5FO CP-60 adams@sgi.com
http://reality.sgi.com/employees/adams_dallas/
WIMPS: Qs=000 30m=0 17m=0 12m=0 States=00/00/00
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