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

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

Why are we really here?

• RF communication devices• uProcessor / FPGA based control circuits• PC Board design and manufacture• Mastering surface mount technology• Microprocessor programming• and more

What would this organization do?

Help people learn about and make -

For Example

A Reflow Oven Project

•Simplifies SMD soldering

•Improves soldering consistency

•Represents a group resource

Scott - KC5VVB

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 ARDFHardware / Software Update

Jerry Boyd, WB8WFK

(Hardware and FPGA VHDL )

Mike Pendley, K5ATM (PIC Software)

August 2008

The Problem

Our Current FOX Boxes are

– 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 duringtransport to location and interruptoperation

•Lots of opportunity for somethingto 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

A PIC directly controlling a pair of DDS chips

1st Generation Prototype

2nd Generation Prototype

Signal Processor FPGA ($10 Xilinx chip). FPGA, regulators , clock and boot ROM are only features being used on eval board

Mixer

Class C RF amp

OP amp for D/A, AM Modulator & RF power control

Pre driver

Voltage regulator

2nd generation Block Diagram of today's demo hardware

Software2m (VHF) Transmission

modes to be supported– FM MCW Cont carrier– FM MCW keyed carrier– AM MCW Cont carrier– CW– AM MCW keyed carrier– FM packet (1200 baud)– APRS tracker?

145.565 VHFAM Modulation

HF Modes– 80M CW– PSK31?

HF CW 3.58 MHz

What next

• BASIC concept is verified ! I am happy with signal processor operation– 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 …

K5MJE helps KD5JAB build an Elecraft T1 QRP automatic

antenna tuner

Kit Building Support

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 TransformerPCB 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!

• 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.

What would this organization do?

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

√