Archive for the ‘Errors’ Category:

2022-01-05 Electric Dryer And 240 VAC Line

From my reply in FB group I Take Pictures… Steve Spence Said, “your electric stove, water heater, and dryer use the full 240.” I don’t *have* any of those appliances; they’re all natural gas. My coworker asked me to fix her electric dryer that she had just had installed. She said the dryer ran but

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2020-06-23 LM386 1W Mono Amplifier Input Jack Reconfig

A year or so ago I bought a few 1W mono amplifiers from a Chinese eBay seller for cheap – see the attached photos. The only marking on the PC board is YX-1667 but I’m not sure if that’s the potentiometer or the PC board itself. . I found that if I pushed the 3.5mm

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2018-09-02 Mims Mistakes In Audio Amplifier

From FB group Building Transistor Radios, 2018-09-02 I already see one mistake. On p.27, Audio Mixer. The R6 is only 1k. The voltage divider R5 and R6 will give a voltage less than 0.6 at Q1’s base, which means Q1 will not be forward biased enough and the circuit won’t work or else sound distorted.

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2017-08-07 Low Quality Goods

From FB comment There are many factors that affect price.  One part is getting things assembled by underpaid and child (illegal) labor.  Most discounters have been caught buying their goods from these illegal sweatshops, and they still turn a blind eye to these abuses.  The net result is that the quality of the components may

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2017-06-15 Capacitor Leakage Tester Ideas

I was asking about very old capacitors and their shelf life on FB vintage test equipment group.  The guys tell how good the old capacitor testers are because they have the “magic eye” to check for leakage. I was thinking that it would be easy to test any capacitor for leakage.  All that’s needed is

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2017-05-21 22-120 Power Schematic Errors

Posted to FB group 2017 June 8, then a copy here. I found this Radio Shack power supply on  Looks like someone drew it up.  I found a few boo-boos, one being the LED having a 100k current limiting resistor.  It’s not going to be bright. I wonder if BK1 thermal breaker is capable

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2016-10-18 FM Transmitter Uses Power MOSFET

I watched this YouTube video where the author shows his FM transmitter using a big 60 volt power MOSFET. He also shows a very readable photo of the schematic. The video was made several years ago in 2012. He is powering this transmitter by connecting it to eleven 9 volt batteries in series, totalling 99

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