NimbleSig III Bare PCB Descriptions
and Availability Status Note: The NimbleSig III PC boards have been made available for hobbyist experimental purposes only. No warrantee or guarantee of performance is implied for any application.
Oct. 28, 2010: The new version 1.4 boards are now available. If you wish to order a version 1.4 board please email me at: <va7ta@telus.net>
The following improvenments have been made to the new board design:
The errors that resulted in the need for modifications of the version 1.3 board have been corrected.
A pin has been extended for accomodating ISP programming.
Notches are no longer needed along the board edge for the RF connectors.
The board has been extended and mounting holes provided.
The RF detector ground plane has been isolated from the DDS ground plane.
The vias are now protected with solder mask.
The non analog ground vias that were under the DDS chip have been moved to the outside perimeter.
The silkscreen component markings have been improved.
Photo 1A: Main NimbleSig
III version 1.4 Bare PCB
The bare PCB board shown above is needed for the building the main
NimblerSig III module as described in the Jan/Feb issue of QEX Magazine. This board does not require any modifications to run however a simple to implement modification can be done to improve the spectral purity as described in the Test Results Photos . The instructions for implementing the bonded ground modification can be found here:
The version 1.3 boards shown below are no longer available.
Photo 1B: Main NimbleSig
III version 1.3 Bare PCB
The bare PCB board shown in
photo 1B has been superceded with the new version 1.4 board shown in photo 1A. This board is needed for building the main NimblerSig III module as described in the Jan/Feb issue of QEX Magazine.
The size of photos on this page are
probably enlargments depending on the
characteristics of your monitor. As I added a little space between
boards for cutting
(which wasn't needed as the manufacture did the cutting for me) the
size is
slightly larger than the active area of the board. There is a
small amount
(about 20 or 30 mils) of board around the perimeter that could be
trimmed
off if necessary. The digital caliper
measurement I obtained for one of the boards
from the batch was 2.70"x 1.41"x 0.034". The boards are made
from 1/32" (or closest metric equivalent) thickness stock.
PreCaution! As stated in my QEX article these PC boards are designed for small surface mount components, some with very fine lead spacing. Experience with surface mount construction, good skills and tools are needed for successful completion. Amongst my tools I have a stereo microscope and a temperature controlled, hot air soldering station along with high quality tweezers and other hand tools. Please do not attempt this project unless you are prepared for a small surface mount component construction experience.
I have a limited supply of these bare
boards available,
the price is $25.00 each, U.S.A. funds which includes shipping via
air
mail to anywhere in Canada or continental U.S.A. The price
$26.00 each,
U.S.A. funds to most other international destinations.
Photo 2: RS232C
to 3.3V Unipolar Data Converter Bare PCB
20090215: Sorry! These boards are no longer available - please see alternatives listed below.
................................. 20090218 I just noticed SparkFun Electronics in the USA have some interesting alternatives. For RS232 to 3.3V data check out their:
Similar converters can be found on eBay. Search for RS232 TTLand look for an adaper that uses a MAX3232 which can be powered from 3.3 Volts. Note that these require an external source of power where my design will usually derrive power from the serial port.
As I write this the eBay titles for the units I would consider are:
RS232 Serial UART to TTL Converter/Adapter Kit PIC MCU
CP2102 USB/TTL/RS232 Serial Port Converter Transceiver
The last unit looks interesting as it appears it would offer both USB and RS232 interfacing for NS3. I have ordered a few of these via Express Post and plan to try them out.
If available the
very small, bare board shown in photo 2 can be
used to build an inexpensive
adapter for interfacing a
personal computer legacy 9 pin
RS232 serial port to the 3.3V unipolar
data NimbleSig III UART port. This interface is described in more
detail here:
Alternatively a
somewhat more expensive USB port to TTL interface can possibly be
obtained from an eBay vendor. The USB to TTL converter
choice may be more suitable if
your computer does not have any legacy 9 pin
serial ports.
Note that
a 3.3V unipolar, UART serial data interface of one type or another is
needed
to calibrate a
NimbleSig III module.
I have a limited supply of
the bare
boards shown in photo 2
available. The price is $5.00 each.
Shipping is included if ordered with a NimbleSig III PC board otherwise
shipping in a regular letter size
envelope via uninsured air mail
is $1.00 to Canada and the
U.S.A. or $2.00 to other international
destinations. For multiple boards there may be a shipping cost break -
please inquire.
Prices are in USA funds.
Photo 3: NimbleSig III
JTAG Interface Cross Connection Bare PCB
20090505: Sorry! This board is no longer available. It is pretty straight forward to build on a prototype board with some point-to-point wiring.
The tiny bare PC board shown
in photo 3 above is useful for connecting a JTAG interface to NimbleSig
III for
programming and/or custom software development. This board is only
needed if you plan to set up a software development
workstation for developing a different control program for the
NimbleSig III hardware. This board is described
in part II
of my QEX article.
This board is less than perfect as
there is not sufficient room for key alignment shrouded header
connectors thus one must be careful when connecting to ensure the
proper alignment. The ribbon cable orientation that
is
needed for proper alignment is a bit awkward. There is an error in
the silkscreen pin numbering. The Pins 1 & 2 and
Pins 9 & 10
silkscreen lettering for the 10 pin connector are reversed. Proper
connector orientation can be confirmed by
checking for continuity
between pin 2 of the 10 pin ribbon cable SIP connector to pin 1 of the
20 pin ribbon
header. This is the +3.3V power cross connection line. Care is needed
to ensure the ribbon cables are oriented properly.
I have a limited supply of
the bare
boards shown in photo 2
available. The price is $5.00 each.
Shipping is included if ordered with a NimbleSig III PC board otherwise
shipping in a regular letter size
envelope via uninsured air mail
is $1.00 to Canada and the
U.S.A. or $2.00 to other international
destinations. For multiple boards there may be a shipping cost break -
please inquire.
Prices are in USA funds.
