Hi, Bill Howzabout a generator that goes from 1 Hz to 40 MHz with 1 Hz resolution, adjustable cursor so you can step any of the 8 digits, presettable offsets for if frequency, repeater offset, or r.i.t., directly synthesized output so almost no phase noise and 12 bit waveform accuracy? How about a price tag of less than $20 for all the major parts? Start by Googling dd_synth.asm for control software, and rather than buying the PCB recommended in the notes at the head of the program, search for AD9850 on Ebay for the synthesizer board and LCD 16x2 for the display. A 16f628a PIC is a couple bucks. Both the display pinout and the synthesizer pinout match standard perfboard. For a little more than $10 more get the AD9851 board and the upper frequency limit is 60 MHz.
A better way to transistorize the old tube-type generator is to use a dual-gate RF mosfet for the oscillator. You can trim the gain for waveform purity by adjusting the bias on gate 2. Once you find the optimum bias on each band, diode-switch the bias level with the bandswitch. Since gate 2 has an extremely high impedance you can use resistors in excess of a megohm, so it won't affect the Q of the tank coil.
In response to popular demand, "SolderSmoke -- Global Adventures in Wireless Electronics" is now available as an e-book for Amazon's Kindle.
Here's the site:
For the print version:
For shipping from a printer in the U.S. (probably better for N. American buyers) Click here: SolderSmoke USA Version
For shipping from a printer in the UK, Spain, or the USA (probably better for UK and other European buyers)
Click here: SolderSmoke EU Version
The two versions are identical, except for a minor difference in the paper used. That's why the prices are a bit different.
Bill's OTHER Book (Warning: Not About Radio)
Click on the image to learn more
W4HBK's QRSS Grabber: The Amazing Pensacola Snapper (Live!)