| Electronics > Beginners |
| Crystal Radio Breadboard - Zero Sound |
| (1/9) > >> |
| t1d:
I breadboarded this circuit. I have zero sound, not even background sizzle. - All components are of decent grade and proofed. Most came from a Crystal Radio parts house. I understand that a new earphone can be "jammed," but this one is sounding on a known source. - All connections have proven connectivity, point-to-point. - The ground is solid and is to Earth. - The antenna is double strand zip cord of long length, maybe 50+ feet. However, I have not strung it out; it is still on the spool. Each strand is soldered in parallel. This should give good volume. - The diode is germanium; 1N34A. - There are local stations. - I am using a 0-335pF variable capacitor; Pin #1 and GND. Data Sheet Attached. It operates CCW, but this is of no operational consequence. - I have varied the direction of the diode with no improvement. - I did not have a 0.001uF smoothing cap, so I used a 0.01uF cap. I have removed it from the circuit, with no improvement. I have reviewed the circuit and, if there is an error, I just can't see it. So, your help, please and thank you. |
| Photon939:
What earphone are you using? A crystal radio is supposed to use a crystal earphone (piezo or similar?) they are very high impedance which is required to run from a crystal radio. A regular 16 ohm magnetic voice coil headphone will probably just short out the crystal radio and result in no audio. |
| t1d:
--- Quote from: Photon939 on December 19, 2018, 04:29:42 pm ---What earphone are you using? A crystal radio is supposed to use a crystal earphone (piezo or similar?) they are very high impedance which is required to run from a crystal radio. A regular 16 ohm magnetic voice coil headphone will probably just short out the crystal radio and result in no audio. --- End quote --- Thank you for your help. The earphone is of the proper type that you specify and it came from a Crystal Radio parts supplier. It is very sensitive and hurt my ear on testing. |
| alanb:
A few things to check:- 1- Are your local stations AM 2- Is the resonant frequency of your circuit in their range use formula f= 1 /(2pi sqroot(LC)) 3 - the loading of the earphone and parallel cap may be too great for the circuit. Are you using high impendence earphones? Reduce or remove C1 Good luck. |
| alanb:
I notice that you say your antenna is still on the spool. You should unwind it and get it outside. |
| Navigation |
| Message Index |
| Next page |