ic....sori did't notice it ther
does any mind telling me wats a emitter resistor?
if i m asking wrong question sori cuz i m reali noob here...

 

Look at hundreds of FM transmitter circuits in Google. They all have an emitter resistor like this:

Attached Thumbnails

 

__________________
Uncle $crooge

 

I keep getting PMs from this guy.

No it won't work if it is made on a breadboard.
It will work if it is made compactly on a pcb or on Veroboard.

I made mine with Veroboard and the circuit is small.
Here is a pic that shows a mess of a circuit that does not work because its parts are spread out all over the place, and my circuit that is compact even though it has many more parts.

Attached Thumbnails

 

__________________
Uncle $crooge

 

I do not need 30 miles ,
but for dog tracking up to 1 mile.(Using time difference of arriving signal, or pseudo Doppler)
Do not worry I have amateur radio license and law say I can use frequency exactly determined by lay, power and modulation.
So I need something with almost practically zero drift , exact frequency (out side amateur frequency I violate law) small battery consumption,
low voltage.
Very old transmitter used for wild animal tracking, look like good, but semiconductors 40 year before and today are not same.
(original blue print are just a little change according today electronic components)
Anybody have fresh idea?
Thank you.

P.S. Today for wild animals nobody use such simple device.
P.S.S. Now professional device use satellite ,GPS , not simple homing principle. But I do not need GPS and other for me expensive device.

Attached Thumbnails

 

 

hi, hop you dun mind me asking noob question...
if you got coil d y do you need crystal sumore?
i dun quite get how the circuit works?

 

"Hop, dun, d, y, sum". Please speak in English, not in shorthand.

A crystal gives a very accurate frequency. It also has a coil and capacitor tuned circuit.

A coil and capacitor tuned circuit allows the frequency to be changed if something moves toward or moves away from the antenna because then the tuning capacitance is changed by stray capacitance.

I think the crystal oscillator will stop if something moves toward or moves away from the antenna.

__________________
Uncle $crooge

 

Coil and capacitor (I am not invented this, schematic diagram is from professional device early 1960 ) need because oscillator work on 3 time higher frequency than crystal frequency.
I do not know how type crystal (quality)was used in original wild animal tracking device 40-45 year before. But now it is easy found newer used computers crystal, petty cheap.
Exactly Uncle Scrooge, it possible some change frequency on output if you multiple few time basic crystal frequencies. (I was long ago use on amateur frequency transmitter with 18 multiply,from 8MHz to 144MHz and easy drift 25 kHz + - )
Problem stopping oscillation, good idea Uncle Scrooge, this simple oscillator not simple like look maybe, it work on rf frequency, but also on-off to save battery(Low oscillation too). So I try found something secure in work.

 

high power trnsmiter

 

i have already tried to solder one myself.
as in the image

But i can't get the frequency of a Fm radio frequency range.
Can someone help me and point out the mistake that i have made?
all the components i got are the same from the circuit diagram.
Thanks a lot.

 

Which circuit diagram?
You need to build HF oscillators on a board with ground plane on one side, short leads on all components, and good power supply decoupling.

__________________
Ron

 

The instructions say to make the coil "close wound". The turns on your coil are much too far apart which causes the frequency to be too high. The wire for the coil is supposed to be insulated with enamel so that when the close turns are touching then they do not short together.

My FM transmitter has "close wound" turns.

Attached Thumbnails

 

__________________
Uncle $crooge

 

How to insulate the coil with enamel? do you mind explaining how to do that?
That means if the coil is further apart will get higher frequency?
My coil is not over frequency but not enought frequency, is it cause of there is no insulation?

erm, I am sorry do you mind explaining more or do you have a link that i can refer to about HF oscillators? I am new to electronics. Thanks

 

I buy Twin 8100 board. You can get it directly from Twin, or from Fry's Electronics. I buy the 10 inch x 20 inch board, and cut off pieces for my little prototypes. You can buy whatever size you need. Use the plane as ground plane. I use 0.1" square grid graph paper to lay out my circuit before I build it.
I have also used single-sided copperclad board and drilled holes and cut pads with a pad cutter (I can't believe they cost US $64 ).You can also use the dead bug method (scroll down).
You can also use Veroboard for small circuits that don't need a ground plane.

__________________
Ron

 

Thanks for the info. But i have already soldered on a veroboard.
I just don't know how to insulate the coil with enamel.

 

I used wire that is made with an enamel insulating coating. I got it from a speaker's crossover coil. A transformer also has enamel insulated wire.

The frequency of your transmitter is too high because the turns on the coil are too far apart. The turns are supposed to be tight together and the wire is supposed to have enamel insulation.

My FM transmitter is made on Veroboard that is also called stripboard because it has parallel copper strips.

__________________
Uncle $crooge