My post to FB Aug 14 Does anyone know about the timelines on what I’m talking about below? The early TRs (transistor radios) were AM only because the germanium transistors available were not capable of FM frequencies. The first TR was the Regency, and it used the Texas Instruments transistors that were similar to the
(Read More…)
From FB comment More than 3 decades ago I took programming classes using a mainframe and minicomputer. The error messages were numerous and cryptic, and those were for just a single mistake, such a missing right parenthesis. One would think that since then, the compilers would be more helpful, but it doesn’t seem so. I’m
(Read More…)
From FB comment I got an ultrasonic cockroach ‘repeller’ from someone who had it on the kitchen counter. I opened it up and found it was full of cockroach carcasses. Looks like it attracted cockroaches instead of repelling them. They probably sprayed real cockroach killer in it. Since it was obvious that it didn’t work,
(Read More…)
2017-07-31 from FB reply by Phillip Grace The worst is damage from leaking batteries and flood damage. The latter isn’t always apparent at first until you open up the set and find signs of sediment or corrosion. Common problems are of course failed capacitors, physical damage, and bad/failed repair attempts and tampering. Taken care of,
(Read More…)
from FB reply 2017_07_27 Richard Robertson Look at this schematic of a typical laptop charger. Notice that the left side has the two pins of the power plug. They are not polarized, and may be inserted into the socket either way. No pin for ‘ground’ or ‘earth’ is shown. Notice that the ‘ground’ or ‘earth’
(Read More…)
Reply to a FB comment about using an incandescent light in series with a repaired equipment to limit the current when it’s first turned on. You can still get incandescent lights around 40W, but they are called appliance lights. You can’t expect a LED light to work in a dryer or oven. Also there are
(Read More…)
I took an electronic technician class at Compton College back in ’66, and the teacher gave us an assignment to work on the antique SCR RADAR sitting outside the classroom. We found that the antenna would rotate but it wouldn’t transmit. We had the schematics and diagrams for it, so I started looking for some
(Read More…)
I’ve thought about using a DC motor as a generator to charge a super capacitor or battery, using human (leg) power. If I get an exercise bike, I would like it to do some useful work. Say, connect the capacitors or battery to a DC to DC converter to make 5V to charge my cellphone.
(Read More…)
The guy in FB group asked how to charge his 5VDC phone with a 12V solar panel. Several others said to use a 7805 V regulator to drop the 12VDC down to 5VDC. This will do the job, but I told them that the 7805 wastes most of the power as heat, and only a
(Read More…)
