widerangesignalsource

Wide Range Signal Source

Design and Construction of an LF through 56 MHz Signal Source

While this is a project in it's own right, it is also a building block for future test equipment, receivers, transmitters, and transceivers.

There are two approaches to this objective:

• Build a very stable oscillator that covers 28 to 56 MHz and use binary dividers to obtain the lower frequency outputs.
• Build a very stable LF oscillator and use PLL techniques to multiply that to higher frequencies.

Initial efforts will focus on the first method.

Work In Progress...More Info Later

Several issues have to be resolved for this to be a successful design.

• Frequency Stability:
• Two possibilities come to mind; (1) apply Huff and Puff Stabilization, and (2) incorporate Frequency Locked Loop technique in the digital frequency dial.
• Frequency Readout:
• A digital frequency counter and LCD display can be driven by signal 'after the bandswitch' to show actual output frequency. This may be an AVR microcontroller or PIC microcontroller based design...not sure which at this stage in development.
• Fixed (5V) and variable (0-5V) outputs:
• Simple resistive dividers for the 0-to-5V output is problematic because the impedance would change as the level is changed. Some sort of emitter follower with output pad for proper impedance termination is envisioned at this stage in the design.