Check out my other video about the first stereo cassette deck ever made. Before this, cassettes were mono and intended only for dictation. Watch the video and take a trip back in time, baby! ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-xFlG4m0uqUo.html
Wow, what a treasure trove of information! As a 30+ year analog EE, I know this is the real deal, and it's clearly explained for novices too without dumbing down the content.
terrific video! explained clearly, no annoying music or back ground noise. thank you, theses videos are a huge help to a unskilled, not terribly bright novice
I really could use some one on one mentorship on radio repair but this video series has been very helpful with getting my feet wet. Just got my first radio ( a zenith cube 5R216). Recapped it and went to power up with a dim bulb tester. Nothing…did a continuity check on the power supply and the transformer had an open primary. Got a new transformer coming tomorrow so hopefully I can figure out how to wire it up correctly.
Good luck, Joe. I hope your Zenith powers up with the new transformer. If you have any questions along the way, feel free to comment on one of my videos. I usually try to respond fairly quickly. And be careful about getting your feet wet. Not the best thing, perhaps, when working with household electricity!
@@FluxCondenser Thanks. I’m going to have questions for sure. I’m confused about the center tap on the high voltage coil of the new power transformer and where that lead connects but I think it will become more clear once I get the new transformer (Hammond 270dx) and read the voltages.
Why do some AM alignment instructions tell you to connect the antenna terminal to 455 Khz to align the IF stages. How does the variable condenser tune 455 KHz if it's designed for approx. 600 to 1400 KHz. Does 455Khz always pass thru the variable condenser downstream to the IF stages? How?
Well, to understand that you first need to understand the concept of a superhet radio. No matter what frequency you’re tuned to, all frequencies are changed to the IF frequency. It’s really a fascinating process and I recommend you check out the other videos in this series which will explain all. ru-vid.com/group/PLCH_MMh8A6cFXw-TQ3UrIp5MA5C9EjSFs
Hi, Randy. I’m not familiar and have never serviced that type of radio, so you’d have to ask elsewhere or consult the service manual for your device. That said, it’s my understanding that all modern analog radio systems use superheterodyne technology so the procedure of adjusting the IF transformers, tuning the oscillator and variable capacitor are likely similar in many respects.
The variac you show when advising to use an isolation transformer is usually NOT an isolation transformer. It's an autotransformer. It provides no protection of the sort you advocate. It's essential to know the difference.
YES, SOME VARIACS ARE ISOLATED, just as the one shown in the video. Before commenting otherwise, please visit the Variac site for confirmation or click this link: variac.com/staco/PDFCutSheets/VT%20isolated.pdf Note, that yes, the ground of the output and the ground only is not isolated, as it’s connected to the chassis. The hot and neutral ARE isolated and for 2-prong antique equipment this is, of course, not an issue. If someone needs to isolate the ground, for a three prong grounded plug, a simple cheater plug is all that is required. A quote from Variac: “Isolated Series: The isolated variable transformer has a separate primary winding which is electrically isolated from the secondary or output winding. Either side of the output can be grounded independently of the supply line, making them safe for all industrial, classroom, and laboratory applications where an isolated output without a common ground connection is required.“ The model shown in the video clearly states on the chassis, “isolated.” I’ve have confirmed this with multiple tests. Not everything that looks alike is the same. www.amazon.com/gp/customer-reviews/R3FWK0HBJYE7AJ/ www.allelectronics.com/item/sc-10t/10-amp-variable-transformer-w/isolated-output/1.html
Hello, maybe you can help me. I need to align the FM on a Zenith model H723 radio. The sheet states to attach the high side of my signal generator to the ungrounded shield over the FM converter tube. However, the shield is riveted to the chassis which is ground. So, where do I attach it?
@@eugenetheodore2956 No problem. Good luck with your project. You may also have luck just clipping the signal generator lead to the insulation of the wire going to the grid, close to the tube. You’re just trying to pump some RF into the tube as closely as you can and there’s lots of ways to accomplish this.
I’ve done another video showing more details and tests about the Variac shown in this available which you watch here: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-8o7HtGTvBvA.html
