I'm thoroughly enjoying this radio restoration series for beginners. Keep up the good work Ron: you're providing an excellent service for anyone who is either wanting to know how to repair a Vintage Radio, or for someone, say near retirement, who is looking for ideas to begin a hobby. Cheers my friend, Phil. P.s, don' forget to add safety disclaimers ...very important.
Phil, you are correct... I will need to start doing that ASAP..... you are absolutely right..... thank you my friend.... I hope it helps people. Cheers and stay well - Ron
I was following along watching, and looking at the schematic of my radio, and the tube data, and there was a dash for one of the expected readings, and I was sitting here wondering if that meant 0 or what, and then you ran into the exact same problem and explained it, ha! Thanks for the videos!
Well I would say you covered a lot of troubleshooting topics Ron doing a great job. Yes restringing a radio is one of Bills least favorite and mine as well I still have a Collins 75A3 Receiver that I have to restring and have been putting it off because its a bear to get into.
Nice job Ron and you are putting that signal tracer through its paces, I noticed you have a loud hum coming from the ST before it is hooked up ti the circuit, maybe it needs a shielded cable. Could that be one of the problems Dough had mentioned?
Ron, I have been following this series, you have done a great job. Thank you. I have a question regarding the non-negative grid voltage in the cathode bias circuit. My understanding is that typically the grid voltage in a vacuum tube has a negative potential relative to the cathode. This prevents grid current flow. When a circuit has a grounded cathode (Fixed Bias), measuring the grid voltage to ground is the same as measuring the grid voltage relative to the cathode. When Cathode biasing is used, the cathode is raised above ground potential, therefore, measuring the grid voltage relative to ground is no longer negative; however, if you measure the grid voltage relative to the cathode voltage, even in a cathode bias configuration, it will still be negative. Is my understanding correct?
I wonder if those paralleled resistors were intentional for the increased power rating. I noticed you don’t really dwell on power rating of the resistors you replaced.
I would desperately like to see a video that solves a "weak signal" problem. I recently tuned up an old RCA radio with a signal generator and all seemed well but with the antenna I could only get about 3 AM stations living not too far from Philly.
Keep plugging my friend. This is a very good follow along series and I hope some out there pick up on this stuff. btw^^^^^^ you are coming up on 500 subs ^^^^^^^^^^ ;p)
Hello, I have just found your channel and I am finding it very helpful. One question, why does the dial light vary in brightness as you probe around with the signal tracer?.
Peter, glad you are enjoying these videos. I never noticed that but you are correct. What you are seeing is a strobing effect from the 6V being affected by the signal tracer causing shorts and changes in voltage. I will have to open up that radio again and see if that happens. Good catch !!!
It may be optical illusion of the video, but it looks like there is a couple of places you have where capacitors are wired in series. If true, that cannot be correct. You might want to check with the schematic and make sure you haven't been mislead by what a previous repair had wrong.
Mjr1999 - I am glad you pointed that out. It was on my list of things to check and I never got to it. It also seemed wrong to me when I replaced the caps, so now I will go back and check and make the proper adjustments. I will let you know what I find. Thank you for reminding me !!!!! - Ron
Knowledgeable, but a few flaws. (1) To redundant. Recaps to much. (2) I don't agree with his wiring skills. I never like hook and loop and tagging onto existing leads, makes for a messy looking reconstruction. If cutting back on the redundancy, he wouldn't have to have so many " parts ".
