Comments on: 200M FM Transmitter

By: munna

munna — Sun, 05 Feb 2012 13:10:46 +0000

I’m not able to make the inductor. I assembled all the parts in PCB accurately but it doesn’t work. What can i do. Please help me.

By: munna

munna — Fri, 03 Feb 2012 10:05:10 +0000

There is no specific volt identified for the capacitors. I don’t understand capacitors of which volt i’ll use for making a FM transmitter. Please help me……

By: munna

munna — Fri, 03 Feb 2012 10:03:27 +0000

There is no specific volt identified for the capacitors. I don’t understand capacitors of which volt i’ll use for making a FM transmitter. Please help me.

By: Rex

Rex — Sat, 21 Jan 2012 02:11:16 +0000

Sir, I’m not able to make the inductors ………. can please tell me the exact no. of turns and the diameter of the inductors, especially of the 1mH one!

Thank you.

By: seetharaman

seetharaman — Thu, 05 Jan 2012 17:08:09 +0000

Hi Mike Q1 is the audio amplifier. Q2 is the colpitts oscillator and the oscillator is modulated at the emitter(Q2)with audio and with the passive tank circuit the modulated RF signal is radiated.

By: mike

mike — Wed, 04 Jan 2012 22:35:28 +0000

Thanks Seetharaman It’s a good idea but I’ve another question. Can you explain me why “Q2 performs the job of oscillator and modulator”? I thought that tank circuit is oscillator but Q1 is amplifire so how transistor can create oscillations?

By: Seetharaman

Seetharaman — Wed, 04 Jan 2012 03:37:38 +0000

Hi Atul 3.9, 5.6 PF can be used here.
Hi Mike you can add a 22PF fixed capacitor in parallel with the existing C5.

By: mike

mike — Sat, 31 Dec 2011 16:29:47 +0000

I’d like to have a tramsmitter with a range about 100MHz so may I use 10-30pF variable capacitor to get lower frequencies?

By: Atul

Atul — Mon, 26 Dec 2011 15:03:49 +0000

plz suggest me anthr capacitor instead of 4.7pf feedback capacitor of T2.

By: seetharaman

seetharaman — Sat, 24 Dec 2011 18:33:29 +0000

Hi Meleja yes with C5 you can set the frequency.