vfo 144mhz

I am looking into designing and building my own 2 meter receiver, and the first step is to build an oscillator. I have opted for the variable frequency because I feel it is best suited to my purposes. Does anyone know how to build one for the 2 meter (UHF) band?

-KE5HOB

You can build a VFO with a microcontroller ..
Here ia an example of a VFO with PIC1684: http://www.qsl.net/yo5ofh/projects/d...pb/dds_vfo.htm
If you think this VFO is to complicated, more VFOs are here:
http://www.pan-tex.net/usr/r/receivers/svfo.htm

Quite often in 2m receivers the first IF is 10.7MHz ..
In this case you will need ≈14MHz VFO and 120MHz from the output of an 60MHz crystal oscillator ( http://www.vectron.com/products/xo/xo_prec_index.htm ) ..
Take a look at the attached pictures .. in your case it won't be 80MHz but 60MHz ..
More details on some inductors can be found at: http://homepage.eircom.net/~ei9gq/2m.html

Regards,
IanP

VCO for 144MHz

I have used the NE604 or the NE605 (includes IF, RSSI etc) The VCO is good up to about 200 MHz. This is really simple to implement.
http://www.semiconductors.philips.co...ets/SA602A.pdf

You might try the Maxim product. It is very easy to use. The varicap is in the IC. You need only few external components.

http://pdfserv.maxim-ic.com/en/ds/MAX2605-MAX2609.pdf

You have something against minicircuits? JTOS150 or POS200? Can't afford S13?

Vfone can you tell us what type of oscillator the one you posted is?

I am trying to find more info on your circuit ;)

In school a teacher told us: ?Later, you are going to design a lot of Colpitts oscillators, even your name is not Colpitts?

I am attaching a snapshot of the simulation of this oscillator.