FM Tracking Transmitter resistor help

Thread Starter

markosillypig

Joined Jul 21, 2008
188
hi all
i'm making an fm tracking transmitter but i'm having trouble getting hold of sensibly priced 4m3 resistors
so i was wondering if it has to be a 4m3 or could i use a
4m7 instead if its no good i will get a 3m3 and 1 meg in series
here is the schematic and component list

cheers
marko

Resistors:
1) 4.3 Meg Ohm
1) 1 Meg Ohm
1) 100 Kilo Ohm
1) 10 Kilo Ohm
1) 220 Ohm




Capacitors:
1) .1 uF
3) .01 uF
1) 5 pF
1) 22 pF
1) 6 to 50 pF Adjustable


1) 4011 Quad NAND gate
1) 2N2222 transistor
 

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MrChips

Joined Oct 2, 2009
30,821
What is the purpose of the 4.3MΩ resistor?
Any thing from 1MΩ to 4.7MΩ should work.
Or put two 2.2MΩ in series.
 

Audioguru

Joined Dec 20, 2007
11,248
Your schematic is upside down.
The positive supply should be at the top and ground should be at the bottom.

The CD4011 quad NAND is a digital electronic IC, not a box. It should have the 4 NAND gates drawn.

Your IC pins are shown from the bottom, not from the top which is normal.

Never mind. It is not yours. You copied it. I also found it in google.

The value of the 4.3M resistor (not 4.3m) and the 0.1uF capacitor simply determine the beeping rate of the transmitter tone. It is about one beep per second.

If you use 3M3 (not 3m3) then the beeps will be a little faster and if you use 4M7 (not 4m7) then the beeps will be a little slower.
 

Thread Starter

markosillypig

Joined Jul 21, 2008
188
schematic is up dated a little with the pin orientation the right way
so is this the correct way and should this circuit work for me ?
cheers
 

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Last edited:

Thread Starter

markosillypig

Joined Jul 21, 2008
188
thanks will alter all text later when i do a better schematic of it
and a PCB diagram and i have taken note on the 4M3 resistor
cheers
 
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