Recent content by AHMEDbr

not yet ...

because the oscillator will have a variable frequency output , so crystal oscillator is not the best choice

below is an example of thermal compensation circuit

i can use à temperature sensor with a voltage controlled capacitor to compensate temperature , i found in net analog device AD590 but it power supply is +5 V , my circuit power supply is 3.3 V so i must use another temperature sensor

the JFET and all the others components because I'm working in HF also i will use electrodes in parallel with C3 for measure soil moisture , and the measurement is sensible to temperature variation

Homework Statement I am designing a local oscillator ( clapp ) whose frequency needs to be kept constant even with varying temperatures , this oscillator have an output frequency 150 MHZ , and power supply 3.3 V Homework Equations which temperature compensation circuit must be used with this...

Thank you for all your advices :)

i Tried with c1=c2= 33p and c3 = 6pf , i find 150 Mhz with a bias resistor of 47k :) thank you all :)

hi everybody , i replaced the diode with a bias resistor as Baluncore said , but i found 147 MHZ , should i add a temperature compensation to my circuit ?

I Tried with c1=c2 = 50 pF and C3 = 5.5 pF i found 150 MHZ :) but when i calculated i found 153 MHZ !

really i don't know , i tried many values but always the same problem

i tried your option but i found 144 MHZ

i'm working in model , so that the inductor value must be kept at 0.24 uH , the VCC must be 3.3 V , and i must use a JFET , the output frequency must be 150 MHZ , can you help me with others design ?

here is my oscillator design , the output frequency must be 150 MHZ but the simulation in ltspice is 147 MHZ

i saw the references but i don't have any solutions