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2018-08-16 Cancer Loves Fat Cells

Sci Am article

https://www.scientificamerican.com/custom-media/cancers-hidden-helper-your-fat/?utm_medium=Display&utm_source=1865911&utm_term=226398931&utm_content=101129235&utm_campaign=20582999

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2018-08-03 GE Special Speaker And Iron Particles

From FB group Building Transistor Radios, Aug 6

This also happens with the meter movements of old analog meters. The iron particles get into the magnet assembly and stop the coil from moving. The only way I’ve found that gets rid of the iron particles is to very gently put a thin piece of steel into the gap and get the particles to stick to it then pull it out. This may have to be one particle at a time, and may take a long time with many particles. You can’t use a magnet because that can demagnetize the speaker magnet. A nonmagnetic tweezers is helpful. One thing I haven’t tried is adhesive tape. But tape could damage a meter movement. A speaker might be less delicate and the tape might remove many particles at a time.

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2018-08-01 Almost Electrocuted by HV

From FB group Bell Telephone… Aug 1

We got to move into our new computer center bldg in ’96, and the old bldg was being demolished. Two guys were jack hammering in a ditch when I drove by going to another site. When I came back later, they were gone but all the equipment was still in the ditch.

Turned out they were cutting into concrete in the trench, and they broke through. Well, this was red colored concrete that identified it as high voltage underground cables, 4 kV at hundreds of amps. When they punctured through the cable, it went off with a huge arcing fireworks, and luckily for us, it ended with the cable going open, not shorted. Scared the hell out of the workers, and they were lucky they didn’t get electrocuted! IIRC, they run red warning tape over the conduit in the dirt. Apparently these fools were never trained on any of that, and it could’ve cost them their lives! 😱

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2018-07-30 How Are LED Lights Made Dimmable?

From FB comment to Bill Sherman’s candelabra lamps.

Bill Sherman
Sometimes I wonder what is meant by dimmable. If a LED light uses hundreds of microfarads for the DC filter capacitor, then when the light is dimmed, the long time constant causes it to flash on and off when it is dimmed. So if the filter capacitor is much smaller, the flashes get much faster until they are too fast for the eye to see. Then the light doesn’t “act weird” when it is dimmed. So is this all that is done to make a LED light dimmable? 😮😮

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2018-07-28 New?? Cisco Phone Set

From FB group Bell Telephone…

Steve Hart
I used to do a shenanigan when we had a Cisco IP phone die. If the ‘factory reset’ didn’t cure the problem, with the help of the ladies, I would give a ‘new’ phone to the client. I would make sure the phone, especially the handset, was cleaned up well. Sometimes I had to use a push pin to remove dirt from the holes in the earpiece, etc. I crimped on new modular plugs to the coiled cord, and checked out the set before deploying it. Then we kept a few spare boxes so I boxed it up so it looked like new before taking it to the workstation. The impression that the people had received a new phone helped with customer satisfaction. Does that make me like a used car dealer?? 😜😏

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2018-07-27 Alan Walker – Faded 1.8 Billion YouTube Views

I’ve watched a lot of YouTube videos totally unrelated to music, and I hear the instrumental version of this over and over, but until now I was never able to find out about it. I had the earworm, I just recorded it and played it while on the road. I found out that since he purposely didn’t copyright it, there were scores or hundreds of similar derivative tunes. I backtracked and finally came across these other artists, and I finally caught up with this guy, Alan Walker. This one song, “Faded” has over 1.8 Billion (with a B! ) views on YouTube alone! Looks like hundreds of millions of others are loving his music! You can search for his name on YouTube and find his and other artists.

What’s the matter with me? This version is so melancholy it brings tears to my eyes. Faded: http://www.youtube.com/watch?v=bDmzGLrdjxQ&list=PLa84ByUjbtqNalEYnkql2_mAGBY2Xkhi1

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2018-07-26 Transistors, ECG, Motorola HEP Line, etc.

From FB group Building Transistor Radios

Wayne Leake
Yeah, the 2N3904 is E B C, THE ‘945 is E C B. Watch out the leads don’t touch and short. 😝

I have the Moto HEP catalogs, if you need to find out what it’s equivalent to.

When National Semiconductor came out with their catalogs they gave the ‘process’ that a certain transistor was selected from. So I could see that the 2N4124 was from the same process as the 2N3904. So I knew that the 2N3904 was a higher voltage version of a 2N4124.

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2018-07-25 How Stable Are Regen Reflex Radios?

From the FB group Building Transistor Radios

Regenerative / reflex designs are not as stable as superheterodyne radios. One problem is the design depends on factors that are not predictable such as gain and feedback, which are not linear. The regenerative reflex depends on the circuit being on the verge of oscillation, which is not linear.

I’m not saying that the circuit cannot be stable. But the manufacturers built thousands of them with parts that were made especially for the circuit. If you were to do the same thing, you would get good results. But I assume that the average hobbyist doesn’t have the ability to do this.

I have built several of the regenerative receivers and I’ve had poor results with all of them.

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2018-07-24 “Boy’s Radio” Reflex Schematic

From FB group Building Transistor Radios

Willie Barnett
I see from the schematic that this is a reflex regen. They did something else that is very seldom seen, the volume control acts not as a normal variable voltage divider, but instead as a variable shunt load across the secondary of the driver transformer. This is to provide a load at audio frequencies to the reflex stage. It’s not a good design because the secondary of the driver transformer is nearly shorted at low volume levels.

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2018-07-24 “Boy’s Radio” Reflex Schematic

From FB group Building Transistor Radios

Willie Barnett
I see from the schematic that this is a reflex regen. They did something else that is very seldom seen, the volume control acts not as a normal variable voltage divider, but instead as a variable shunt load across the secondary of the driver transformer. This is to provide a load at audio frequencies to the reflex stage. It’s not a good design because the secondary of the driver transformer is nearly shorted at low volume levels.

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