Science Buddies: "Ask an Expert"

Hi
We are trying to do this experiment for the school Science fair.
https://www.sciencebuddies.org/science- ... #procedure

We got all the products (except batteries and audio cable) from Science buddies .We used Ipad as the sound source and regular headphones as the phone cable.We used 4 AA batteries of 1.2V.We used the radio (530kHz-1700kHz) as the reciever.There is no output.
Should we change the phone cable?
As per the procedure

(Use your wire strippers to cut the 3.5 mm audio cable in half. It has three wires inside: left and right audio (with red and white insulation), and ground (uninsulated).
Strip about 5 mm of insulation off the ends of the left and right audio wires.)

but the headphone has only 2 wires.How should we connect? Can we get the audio cable from Radio Shack?Please let us know the manufacture number.
What else could be the problem?
Looking forward to hear soon.

khadeejabaqui - Sorry you're having a problem. A couple of questions. When you power the transmitter up do you detect any sound from your AM radio tuned to 1000 hKz. A slight rushing sound (or quieting of the background noise above and below 1000 kHz) is the RF carrier being detected by the AM radio. If you get that effect your transmitter is producing RF energy at 1000 kHz (or 1 megahertz). If you can's detect the presence of RF, power everything off and carefully retrace all your wiring.

If you have RF, the problem is that you are not getting any Amplitude Modulation of the carrier signal by the music from your phone or other sound source. A typical smart phone or tablet has a stereo output. That was the description of the red and white wire and common ground. In this experiment, you only want to use either the red or white wire (only one audio channel) and ground. If you used a single earphone with just two wires, no problem. Just don't connect the red and white wire to the transformer. You will likely get no modulation. Try these ideas and let us know if you are successful.

Rick Marz

Hi
Thank you so much for your reply.We tried putting only one end of earphone in A5.We get quieting of the background noise at 1MHz on the home radio,but no other output.I am hoping that there is RF at the output,but what should we do to hear the output?
I tried reversing the transformer ,but did not help.I believe we have used 1000 ohms to 8 ohms transformer. Are we not supposed to use step up transformer(8 ohms to 1000 ohms).
Also we used 4 AA batteries of 1.2v each.The specification of Crystal Oscillator mention 5V input voltage.Can that be the problem?
We live in Fremont,CA-94538.Can the local AM radio signal be the problem.There is a radio station at 1010 kHz frequency from San Francisco. But I can clearly hear blank when I turn on and noise when I turn off the battery,so I think we are catching the signal.Can you please search for any local signals at 1MHz in my area.
We tried computer ,IPad and Ipod as the sound source.What can we do intensify the input signal?Do you think we should try with the 3.5mm audio cable?
Should I send picture of my circuit .May be that will help.
Please let know.