Willen
Well-Known Member
Hi Willen,
you might use any of the mentioned transistors plus a BC550.
Can I use there PN2222 as a replacement of 2n2222? Are they same?
Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature may not be available in some browsers.
Hi Willen,
you might use any of the mentioned transistors plus a BC550.
Compare their spec's on their datasheets.Can I use there PN2222 as a replacement of 2n2222? Are they same?
The 2N2222 is very old so its detailed datasheet might not be available.
I think a PN2222 is the chip of an old 2N2222 in a modern plastic case.
I get datasheets from www.datasheetarchive.com where they show thousands of manufacturers of a transistor.I found, you are saying several times that ''some old component's datasheet is almost not available.'' But I am in confuse, why are saying that? Because I can download or browse easily all these old component's datasheet on the internet. Like spec's datasheet at americanmicrosemi.com and etc. Are they not valid datasheet?
This is my FM transmitter circuit. I built it on stripboard and I cut the strips with a drill bit. The strips form half of a pcb.
This is my FM transmitter circuit. I built it on stripboard and I cut the strips with a drill bit. The strips form half of a pcb.
If you wanted to be correct, you would run 50 ohm coax and use a 1/4 wave balun made from a piece of 75 ohm coax.
My FM transmitter has low output power because its output transistor has a fairly high output impedance and does not match the 75 ohms impedance of its antenna.¤ What is the output impedance of this Tx?
yes.May I use 75 ohm coax and 75 ohm straight dipole without Balun?
The value of the coupling capacitors were calculated for good audio low frequency response.In the circuit, there are two coupler capacitor 0.33uF. Does it critical? May I use 104 or 22n instead of 0.33?
Among many miniature transmitters, I found your is the best one! Please upgrade your Tx with almost 100mW power by adding easily available transistor like 2n2219. It won't be illegal because I think- desining such a circuit is not illegal but transmitting is illegal. Please.....audioguru,
This is my FM transmitter circuit. I built it on stripboard and I cut the strips with a drill bit. The strips form half of a pcb.
Each parallel track is very short so the coupling is almost nothing. That is why I cut each track to the minimum length required.¤ I heared that putting two or more inductors near just like parallel, performs bad because of parasite coupling between each another. It should be in 90 degree or far from each another. But you've put it near and like parallel. Won't it face parasite coupling?
It doesn't matter because I spaced my inductors 3mm above the circuit board.I am designing a PCB layout of your Tx. It is good or bad to keep grounding area under an inductor? (like inductor as a bridge and a grounding copper hub of PCB as a river.) Or better to leave blank?
This is my FM transmitter circuit. I built it on stripboard and I cut the strips with a drill bit. The strips form half of a pcb.