modifying the vfo to a crystal controlled version would fix the stereo issue. Generator Interlock Kit compatible with Cutler Hammer Generator Interlock Kit for BR Series 150 and 200 amp Panels, 1 1/4 - 1 7/16 inches Spacing between main and branch breaker 4.1 out of 5 stars 12 49.99 49. Ive seen very similar circuits using the same switching technique with a 4066. oh and the separation? its fair to poor depending again on the vfo setting. the 19k output has a reasonable sinewave.
this doesnt help trying to keep the stereo locked either. on the scope i found the osc to be a touch jittery. I also tried modding the pilot level using a resistor network. with no audio the carrier sounds like its being overdriven.ĭriving with audio and the sidebands sound bad. this needs some fitering to stop the harmonics. i used a wein bridge osc.īack to this encoder. that osc.!! my one used ALL bc548c,s no chips. [ i built one myself a few years ago using my own design. it only has to be a bit off and the output becomes mono. the separation really depends on the oscillator. anyhow i removed the short and gave it a good check over and wired it up again. i found a vey tiny piece of copper track that was making contact. JUPITER: 3-Band DIGITAL audio processor + Stereo Generator (instead of NSC1) + 990.
NT350: 350W FM TRANSMITTER (Instead of NT250) + 290 OPTION 3. recently i got the pcb out again and had a good check. NT250: 250W FM TRANSMITTER with Built-IN Stereo Generator and Audio Processor + 600 OPTION 2. i had problems with high levels of whistling. T1 = BC547B, BC549C Stereo encoder circuit schematic I have worked with this stereo encoder in my youth and it’s pretty good because has a 70% stereo separation that is pretty good.Ĭ3 = C4 = C5 = C9 = C10 = C12 = 100nF ceramic If you want the best from this mpx stereo encoder use metallic resistors, ceramic capacitor, shielded audio cables for input and MPX output and a good stabilized, filtered 5V power supply. You can use a better T1 like BC549C if you want a higher sound amplification. If your audio source has dc voltage on audio output connect 2 x 0.47uF capacitor on the stereo encoder inputs. Use metallic resistors and 100nF ceramic capacitor for low noise stereo signal. From R10 adjust the pilot tone signal and from R7 adjust the sound level. To adjust the frequency rotate R13 (multiturn) untill on IC2 pin 10 you measure 19kHz or the stereo led lights up on your stereo receiver. On IC2 pin 10 you can find 19kHz pilot tone frequency. On IC1 2 and 3 pins is the audio output which is amplified by T1 (current amplification). This simple stereo encoder circuit schematic is build with 2 IC MMC4066E and MMC4047 and one transistor BC547B.
0 kommentar(er)
