Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Need help with Max2606 Fm transmitter

Status
Not open for further replies.

Bryan76

New Member
I got the following circuit in a kit. I built the circuit on a bread board and tested it with no luck. I rebuilt it 2 times to make sure I didnt miss anything. Still not working. Im am positive the circuit is built correctly! The only thing I can think of is that the IC is damaged. Can anyone offer adivce on how to test the IC for damage? The only test equipment I have on hand is a multimeter. Thanks in advance.


**broken link removed**
 
When you say "breadboard" do you mean a solderless breadboard? That will not work, this chip must be assembled to a pcb, either using a perfboard or a custom pcb. Solderless breadboards have too much inter-contact parasitic capacitance which will likely stop the oscillator working, or will pull it way off frequency.

Can you provide a photo of your assembly?

My experience is that the first thing we suspect is that the IC is blown but this has usually been wrong. I've almost never had a failed IC except where power supply and ground were reversed (and the failure was pretty obvious as the smoke got out of the IC).
 
Last edited:
RadioRon said:
When you say "breadboard" do you mean a solderless breadboard? That will not work, this chip must be assembled to a pcb, either using a perfboard or a custom pcb. Solderless breadboards have too much inter-contact parasitic capacitance which will likely stop the oscillator working, or will pull it way off frequency.

Can you provide a photo of your assembly?

My experience is that the first thing we suspect is that the IC is blown but this has usually been wrong. I've almost never had a failed IC except where power supply and ground were reversed (and the failure was pretty obvious as the smoke got out of the IC).

Yea it is a solderless breadboard. I will put it on a pcb and try again. Thanks...
 
Solderless breadboards have a very high stray capacitance on each of it's connections which is why it's not working. I've never heard a number for the actual capacitance between rows of pins, but they add up.
 
It is a lousy FM transmitter:
1) Its frequency will drift as its battery runs down because it doesn't have a voltage regulator.
2) It doesn't have pre-emphasis (treble boost) like FM radio stations have so an FM radio will cut its treble frequencies and the sound will be like an AM radio or like your stereo with its treble control turned all the way down.
3) It is mono, not stereo.
 
audioguru said:
It is a lousy FM transmitter:
1) Its frequency will drift as its battery runs down because it doesn't have a voltage regulator.
2) It doesn't have pre-emphasis (treble boost) like FM radio stations have so an FM radio will cut its treble frequencies and the sound will be like an AM radio or like your stereo with its treble control turned all the way down.
3) It is mono, not stereo.


I have a 5v regulator installed (9v battery). I understand it will be like an AM radio and that it is not stereo. Can you offer some advice on how i can tell if its even sending a signal?
 
I made a simple field strength circuit to connect to my multimeter for tuning my FM transmitter. About 1m from the transmitter with the antennas parallel and pointing in the same direction it should have an output of about 300mV DC.
 

Attachments

  • FSM.GIF
    FSM.GIF
    2.6 KB · Views: 496
audioguru said:
I made a simple field strength circuit to connect to my multimeter for tuning my FM transmitter. About 1m from the transmitter with the antennas parallel and pointing in the same direction it should have an output of about 300mV DC.

Thank you. :D
 
audioguru said:
I made a simple field strength circuit to connect to my multimeter for tuning my FM transmitter. About 1m from the transmitter with the antennas parallel and pointing in the same direction it should have an output of about 300mV DC.

I have many types of diodes but no 1n34's. Is it possible to use a diffrent type?
 
My field strength circuit picks up every TV broadcast and taxi-cab radio transmission in town if they are strong and are close by.
 
audioguru said:
My field strength circuit picks up every TV broadcast and taxi-cab radio transmission in town if they are strong and are close by.

LOL thats good to know. Its a pretty cool circuit but how can I use it to test my FM transmitter if its picking up other signals? :)
 
My little FM transmitter sprays RF all over my neighbourhood and my workshop. The RF is much weaker than TV broadcasts and taxi-cab transmissions so it is obviously coming from my transmitter when I turn it on.
 
Status
Not open for further replies.

Latest threads

New Articles From Microcontroller Tips

Back
Top