160 KHz Oscillator Transmitter

[Bluepoint SEO]

Hi there its been a while since my last post but I have been checking in.

I'm finding it difficult to find designs for transmission on 160Khz and I've literally guessed putting one together which failed, miserably.

It's only a 9V battery on a short length of wire but I can't get it to work. I have to apologise for the diagram below as its from my broken phone but I used Photoshop to enhance it a little:

Can anyone tell me how to make this work or point me in the correct direction for a good tutorial?

I know it sucks, but I'm still learning of course...

Thanks guys you're all ace.

 

[Arouse1973]

Ok the picture looks shit. Download LT Spice, you can draw circuits in that...its free. Why do you want 160KHz out of interest.
Adam

 

[Bluepoint SEO]

Ok the picture looks shit. Download LT Spice, you can draw circuits in that...its free. Why do you want 160KHz out of interest.
Adam

Lol, 160KHz; there's no radio station here on that frequency. I'll take a look at that LT Spice cheers.

 

[Arouse1973]

What are you trying to do?
Adam

 

[Bluepoint SEO]

Just trying to transmit to my radio short distance of course. I'm trying to figure out crystal oscillators and all about biasing transistors so I need my maths head on and any help from you guys. Downloaded LT Spice taking a look now.

 

[Arouse1973]

http://www.ofcom.org.uk/static/spectrum/fat.html please be aware.
Adam

 

[Arouse1973]

Just trying to transmit to my radio short distance of course. I'm trying to figure out crystal oscillators and all about biasing transistors so I need my maths head on and any help from you guys. Downloaded LT Spice taking a look now.

Good, let me know if you need any help. @Harald Kapp is a wizz with this software, but I can do a bit.
Adam

 

[Bluepoint SEO]

A few centimetres is okay then from what I read. Good website though thanks.

 

[Bluepoint SEO]

Hi again, okay had a fiddle with spice - not ideal but first time using it see below:


This is what I'm thinking, signals come through the input and at a high they turn the transistor on which allows current to pass the oscillator and the frequency (from the base) is modulated and sent to the collector where it goes up the aerial. You see I really need to learn the maths! I'm so impatient.

Thanks

 

[Arouse1973]

Now thats better.

 

[Bluepoint SEO]

haha thanks didn't know how to find symbols like antennas or voltage sources etc.. but it's self explanatory I guess.

 

[(*steve*)]

160kHz, or 1600kHz? The former is very low frequency, the latter is at the upper end of the broadcast band.

 

[Bluepoint SEO]

Oops just checked radio - - 160KHz x 10 lol. Right is it possible for me to get a harmonic frequency? Can't believe I did that!! grr haha.

 

[Bluepoint SEO]

Oops just checked radio - - 160KHz x 10 lol. Right is it possible for me to get a harmonic frequency? Can't believe I did that!! grr haha.

I'm thinking I might pick something up around 88ish MHz... will try. Thanks

 

[duke37]

Is 160kHz in the long wave band?

I think that R1 should be somewhere between 10k abd 100k, a low value will damp the circuit.
The audio input should have a RF bypass, it is a grounded base circuit.
There should be an emitter resistor to take the feedback, what is R3 for?

 

[(*steve*)]

AM for 1600kHz, FM for 88MHz if you want to receive it on a regular radio.

 

[Bluepoint SEO]

I don't know I invented because I have no money to out tonight boo hoo. So I thought I'd stick something up here get a discussion on the go and learn some new tricks.

Can't get to work with your changes you recommended. Hmm. Will keep playing.

Right I've got my mobile plugged straight into this is there something I should be doing first to make the sound modulate the carrier frequency?

 

[Audioguru]

There are many tutorials about transistor crystal oscillators and transistor biasing on the internet.

 

[Bluepoint SEO]

That's great thanks.