AM Frequency transmittor

[superjet]

hey everyone,

I'd like to build an AM radio transmitter,

The signal I am looking to replicate is a 10.8 khz radio carrier frequency with a 30 hz modulation frequency

Can anyone help get me started on this? I am an engineer (mechanical) with basic electrical experience.

What type of circuitry/components would I need to replicate the 10.8khz frequency w/ the 30hz modulation?

thanks!

 

[superjet]

I found this image from another forum, where someone was looking to do the same thing.

**broken link removed**

So my understanding is that I can create the 10.8 khz radio carrier signal with this type of circuit, but I am a little confused about implementing the 30hz modulation.

 

[Hero999]

How about posting the image?

Why do you want to do this? 10.8kHz isn't useful for much.

 

[superjet]

sorry, image inserted.

The purpose is for making a home made remote for those invisible electric fences for dogs

 

[MikeMl]

TRANSMITTER implies you want to transmit a signal using electromagnetic waves (radio). Is that what you need to do?

Or do you just want to make an analog signal which consists of a 10.8KHz Sine Wave whose amplitude is modulated by a a 30Hz Sine wave?

 

[superjet]

I'd imagine I'd need to first create this signal and then transmit it. Since the receiver (dog collar) may be 10-20ft away, i'd be looking to transmit this data from the circuit to the collar

 

[MikeMl]

I have a **broken link removed** that uses a buried inductive loop. Are you just trying to build one from scratch?

 

[Mikebits]

You do realize 10.8 kHz is audio frequency don't you? You will need a really really long antenna.

 

[crutschow]

If the fence uses 10.8kHz, then the signal is likely conducted inductively to the collar through the magnetic field, not with an EM (radio) wave. Thus the range is very limited (the dog has to be near the loop) and it will likely be difficult to generate a signal that the collar will detect from any significant distance.