Wide range VFO

[BeerBelly]

I am designing a crystal controlled VFO to be used on my bench as test equipment. I repair 2-way radios in my business.
Does anyone know of an oscillator design with a really wide range. The range would hopefully be 20mhz to 500mhz, possibly wider.
Am I going to need several oscillators and mixers, or are there designs with very wide ranges?

 

[MikeMl]

By crystal controlled vfo, do you mean a pll synthesizer.?

 

[BeerBelly]

By crystal controlled vfo, do you mean a pll synthesizer.?

Yes
PLL, PIC microcontroller, LCD readout, Menu driven
Sort of a hobby project.

 

[MikeMl]

The Ham Radio literature (QST,QEX) has many articles on frequency synthesizers, some using the chipsets on the Analog Devices page I linked you to...

Some use GPS-disciplined master oscillators (usually 10MHz) to achieve extreme frequency accuracy.

 

[BeerBelly]

Thanks for the link. The ADF4351 looks like quite a chip.
Also thanks for the quick reply.
Usually when I need accuracy, I tune sync to WWV. For this project, I planned to use a 10.240 crystal and maybe a thermal controlled enclosure.