Nigel Goodwin said:Q3 is an RF amplifier, it produces much greater range, and makes it more stable by giving a degree of isolation between the oscillator and aerial.
Nigel Goodwin said:I consider simulators a waste of time, particularly for this type of circuit, where it's not likely to even get close.
Antey said:But in order to work (amplify) the transistor must be properly biased, that is it must work in "normal, active" area (if I translate this correctly), and even without simulation, I don't expect Q3 to work like that... unless of course there's something I can't see or understand. What could it be ?
audioguru said:I don't think the sim program knows anything about Q or RF. It just thinks the transistor's collector is shorted to the supply, and displaying the battery's voltage being modulated. :lol:
Nigel Goodwin said:Q3 is biased by R8 - I don't see your problem?.
Antey said:Nigel Goodwin said:Q3 is biased by R8 - I don't see your problem?.
I'll take it for granted, but still i don't see it
:shock: (sound of hand hitting the forehead ).Nigel Goodwin said:Try studying the different bias classes, for a simple overview :
audioguru said:My Veroboard layout for mod-4 looks like this:
Hi Antey,Antey said:But... I'm afraid to ask
It is difficult making a very high frequency radio transmitter without having a printed circuit board and detailed instructions. Perhaps it is best for you to learn by making a kit that comes with all special parts, a printed circuit board and detailed instructions. :lol:I am not expirenced enough, but I know that there can be some issues regarding additional capacities/inductances...
Or maybe just suggestions about putting all pieces together - especially about making connections and wiring ? I am not expirenced enough, but I know that there can be some issues regarding additional capacities/inductances...
zachtheterrible said:Layout at 100MHZ isnt extremely critical, like in the GHZ region
audioguru said:We are friends so ask what you want. :lol:
audioguru said:Perhaps it is best for you to learn by making a kit that comes with all special parts, a printed circuit board and detailed instructions. :lol:
Antey said:My task is to provide 3 different schematics of FM modulator (100 MHz carrier and 50 kHz deviation ), which both look realistic, and work perfectly in simulator, then preapare detailed calculations and working (under Spice A/D 6.3 ) simulation of one of them.
Nigel Goodwin said:Doing it that way will allow you to do detailed calculations, and should simulate without any problems.
Why?Could Q1, Q2, and Q3 be replaced with three fairchild PN3563's?
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?