Haven't finished the video yet. I had to comment how those induction/capacitance/reactance formula's are planted in my head. It's wonderful to see someone apply them to get the value of your resistance! Now I'll finish watching the video and with my luck it'll be incorrect! Hope not!
A toroid coil for 455 khz is made easily with a T50-15 toroid to get about 121uH that when used with a 1000 pf capacitor, it oscilates at 455 khz. This about 91 turns (7 ft 24 ga wire).
The ringing is likely due too inductance in the leads of the components. You could try to tighten up the loops. you may also want to add a 0.1uF decoupling cap on the Vcc of the hex inverter IC.
I have bunch of radios some of them working.. can we use their (built-in ) oscillators to align troubleshoot and repair other radios! I met a technician that had only a VOM and an analog oscilloscope and he could repair almost any old radio and TV ! he utilized one device to repair the other!
One question i got CMOS cd4011 and ceramica resonator with three pin. how to Connect the ceramic resonator?do i have yo eliminate the to capacitor that goes yo ground??
What's the signal look like with a higher voltage on the CD4049? The datasheet for that chip shows nothing lower than 4.5V under test conditions. I always thought that 5V was minimum for the older CMOS chips.
@@gizmofiddler1 Odd, I just clicked the link and it worked. Here it is again with the "%20" replaced with a space: www.philipstorr.id.au/radio/technical/Crystals Techo.pdf
Haven't finished the video yet. I had to comment how those induction/capacitance/reactance formula's are planted in my head. It's wonderful to see someone apply them to get the value of your resistance! Now I'll finish watching the video and with my luck it'll be incorrect! Hope not!
Great video. Excellent work!
And don't forget to connect the inputs of unused sections of the hex inverter IC to either Vcc or ground!
A toroid coil for 455 khz is made easily with a T50-15 toroid to get about 121uH that when used with a 1000 pf capacitor, it oscilates at 455 khz. This about 91 turns (7 ft 24 ga wire).
The ringing is likely due too inductance in the leads of the components. You could try to tighten up the loops. you may also want to add a 0.1uF decoupling cap on the Vcc of the hex inverter IC.
I have bunch of radios some of them working.. can we use their (built-in ) oscillators to align troubleshoot and repair other radios! I met a technician that had only a VOM and an analog oscilloscope and he could repair almost any old radio and TV ! he utilized one device to repair the other!
One question i got CMOS cd4011 and ceramica resonator with three pin. how to Connect the ceramic resonator?do i have yo eliminate the to capacitor that goes yo ground??
How about covering it with a metal box, that trick has worked for me several times "Shielding".
Any video done on reverse engineering of RC control car circuit of transmitter and receiver
What's the signal look like with a higher voltage on the CD4049? The datasheet for that chip shows nothing lower than 4.5V under test conditions. I always thought that 5V was minimum for the older CMOS chips.
I have a Panasonic RF-728 on the way...do you think it compares to your RF-800???
Post the schematic in PDF . Is Impossible see on the vídeo
See page 8.
www.philipstorr.id.au/radio/technical/Crystals%20Techo.pdf
@@gizmofiddler1 Odd, I just clicked the link and it worked. Here it is again with the "%20" replaced with a space:
www.philipstorr.id.au/radio/technical/Crystals Techo.pdf