Transcript Document

Circuit & Control System Design
& Fabrication – Proposed
Technical Club
Room C, Saturday August 16, 2:00 – 4:00
Goals for today
• Spend ~20 minutes exploring the kinds of
activities such organization could support
• Group Discussion: Is this a good idea?
• Gather names of individuals interested in
participating on a technical level
• Form a small committee to kick start the
group
Albuquerque
Transmitter
Hunters
Why are we here?
Why are we here?
Because we have the Knack!
Why are we here?
Because we have the Knack!
Click image to start video
Why are we really here?
We are proposing the formation of an
organization to preserve and celebrate the
knack! An organization that would support
learning about and the creation of custom
electronics, radio circuits, and control
systems
What would this organization do?
Help people learn about and make • RF communication devices
• uProcessor / FPGA based control circuits
• PC Board design and manufacture
• Mastering surface mount technology
• Microprocessor programming
• and more
For Example
A Reflow Oven Project
Scott - KC5VVB
•Simplifies SMD soldering
•Improves soldering consistency
•Represents a group resource
Precise Temperature
Control
•Three distinct phases
Block Diagram
•Oven
•AC Relay
•Thermocouple
•PIC
Progress
•Output relay working
•AC assembly to be provided
•Thermocouple on hand
To Do
•Complete prototype assembly
•Test temperature control
•Write final code
•Fab PCB
•Complete assembly
Or …
SDR TX Project for ARDF
Hardware / Software Update
August 2008
Jerry Boyd, WB8WFK
(Hardware and FPGA VHDL )
Mike Pendley, K5ATM (PIC Software)
The Problem
Our Current FOX Boxes are
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LARGE and heavy
Tend to fall out of sync
Limited to 2m FM MCW and 80m CW
Programming switches and radios need to be
adjusted to change frequencies and
configuration.
Root Cause of Problem
•All problems can be traced to systems that are wired together
using mutable connectors, cables and equipment interconnected
to function as an ARDF transmitter
•RF gets into and upsets controller
•Radios are not designed for high duty cycle
•Equipment not designed for this application
•Wires can get caught in equipment during
transport to location and interrupt
operation
•Lots of opportunity for something
to go wrong
The Solution
A Software Defined Radio That can
– Dynamically change frequency and modulation modes
– Conserve power during “down” time
– Use “real time clock” to stay in sync and “auto recover”
if power is interrupted after sync
– Phone home with state of health information
– A user interface that is easy to configure
– Shielded enclosure that protects all electronics
– Radio designed for continuous duty cycle (homing
beacon mode)
– Simple alignment that only requires a volt meter, power
meter, and receiver
Software (cont)
For Tracking People on ARDF courses
-Sport ID data packet
sent while TX is off
cycle
-Panic button located
at each control station
to request medical
assistance
1st Generation Prototype
A PIC directly controlling a pair of DDS chips
2nd Generation Prototype
Class C RF amp
Voltage
regulator
OP amp for D/A,
AM Modulator & RF
power control
Signal Processor FPGA
($10 Xilinx chip). FPGA,
regulators , clock and
boot ROM are only
features being used on
eval board
Pre driver
Mixer
2nd generation Block Diagram of
today's demo hardware
Software
2m (VHF) Transmission
modes to be supported
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FM MCW Cont carrier
FM MCW keyed carrier
AM MCW Cont carrier
CW
AM MCW keyed carrier
FM packet (1200 baud)
APRS tracker?
HF Modes
145.565 VHF
AM Modulation
– 80M CW
– PSK31?
HF CW 3.58 MHz
What next
• BASIC concept is verified ! I am happy with
signal processor operation
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Develop CPU board and User interface
Develop SPI based interface to signal processor FPGA
Develop SportIdent and panic button interface
Field test prototype with all of the above functions
• Design PC boards design to include everything
Demo
• Demonstrate Generation 2 prototype system
Some Other Projects
For More Information ….
Come to the club meeting
Or …
Kit Building Support
K5MJE helps KD5JAB build an
Elecraft T1 QRP automatic
antenna tuner
Inventory
After Page 11
After Page 14
After Page 14 (bottom)
T1 and T2 Installed
Control Board
Toroids Installed
Control Board Installed
Installed in Case
Or …
Construction of Dale Hunt’s 80m
ARDF Receiver Kit
Kevin Nichols, KA7OFR
Why 80m ARDF?
• No (well, much much less) reflections or
multipath
• Small antenna & receiver
• Simple to build as a kit
• Transmitters are small
• Fits well with Orienteering
Dale Hunt’s (WB6BYU) 80m ARDF
• Fairly small, hand-held
80m (3.5MHz) ARDF
receiver
• Single stage direct
conversion type receiver
• Easy alignment
• Described in QST,
September 2005
• PCB available from FAR
Circuits
80m ARDF Kit Parts
PCB, Silk Screened
Some Helpful Items
Schematic - +5v Reg
Schematic – Audio Amp
+5v Regulator and Audio Amp
Schematic - VFO
VFO
Right on Frequency
Winding Torroid Transformer
PCB Almost Finished!
A Metal Case
Wooden Loop Antenna Holder
Schematic – Loop Antenna
Threading the Loop
Schematic – Sense Antenna
Sense Antenna
Sense Antenna
Wiring the Front Panel
Ready to Close ‘er Up
The Finished Product!
What would this organization do?
• Hold a minimum (perhaps no) business meetings
• Periodic formal meetings that would feature one or
several technical talks given by members on current
or proposed projects
• Support group buys of components and kits
• Be a source of shared resources
• Coordinate classes on various technologies – e.g.
microprocessor programming, schematic capture,
PCB layout, antenna design, etc.
Goals for today
√ • Spend ~20 minutes exploring the kinds of activities the
organization could support
• Group discussion: Is this a good idea?
• Gather names of individuals interested in participating
on a technical level
• Form a small committee to kick start the group
– Group structure – independent or a SIG associated with an
existing club
– Name of the group
– Frequency and location of meetings
– Other unavoidable administrative stuff