VFO for UHF (144-148mhz) Help please!

[KE5HOB]

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

 

[IanP]

2m vfo

You can build a VFO with a microcontroller ..
Here ia an example of a VFO with PIC1684: http://www.qsl.net/yo5ofh/projects/dds_vfo_by_n2apb/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 ( **broken link removed** ) ..
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: **broken link removed**

Regards,
IanP

 

[vfone]

colpitts vfo

VCO for 144MHz

 

[E-design]

colpitts oscillator 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.
**broken link removed**

 

[boy]

pos200 vco receiver

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

**broken link removed**

 

[biff44]

148 mhz lc oscillator

You have something against minicircuits? JTOS150 or POS200? Can't afford $13?

 

[Kuller]

14mhz vfo design

VCO for 144MHz

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

I am trying to find more info on your circuit

 

[vfone]

vfo 144 mhz

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.