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2018-04-28 COs And Short Term Backup Power

Uncategorized
on April 29th, 2018 by - No Comments

From FB group Bell Telephone of the US…

Dan Bottoms
It seems to me that a good way to avoid generator synch hassles would be to do the same thing that our Exide UPS does. Incoming power is rectified to keep the battery bank charged. It’s passed through to the equipment, until it drops out, when the battery banks take over. So what this is, is a UPS. But there is no interruption in the outgoing power. It is switched electronically, which happens in a fraction of a cycle.

COs have massive 48VDC batteries, so should they be used to full advantage? They can handle thousands of amps. It doesn’t have to be for long, just enough time to start the generators.

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2018-04-26 Ouch! He Gaffed Out While Climbing The Pole

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on April 26th, 2018 by - No Comments

From FB group Bell Telephone of the US…

When I was in the army in Germany, one of the guys in my comms unit was a lineman. He asked me where I was from and I said, So. California.
He said, “Man I couldn’t live there! They have earthquakes!”
I asked him where he was from, and he said, Hollywood, Florida.
I said, why are you complaining about earthquakes? Florida is just as bad, with all the hurricanes!

Later he came in with big bandages on the insides of his upper arms. Someone ask what happened, and he said he “gaffed out”, and grabbed the pole with his arms! 😟 👎

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2018-04-22 Ferrite Loopstick Basics

AM Band Receiver Toroids and Cores
on April 22nd, 2018 by - No Comments

From FB group Building Transistor Radios

Then there is the loopstick. It is deliberately made long and thin to capture the RF magnetic fields. The frequencies that loopsticks are better at capturing are those that require long antennas that would be impractical. So the AM broadcast band is where loopsticks do their best. The loopstick’s ferrite mix is optimized for this band. If the frequencies are higher, the ferrite’s losses increase and the wavelengths become short enough to where reasonably sized whip antennas can do a better job. The ferrite’s mix may work at higher frequencies but not as efficiently, and as the frequency goes higher the efficiency goes down and losses go up.

Jim Glover
I’ve seen antenna terminals connected to a few turns of wire wrapped around the loopstick. I should also say that the AM broadcast band has a lot of natural noise so adding more gain to the radio will amplify that noise along with the signals. If an antenna is added, more signal will be captured and you can then hear the signal, where before you only heard noise. But if the antenna signal is out of phase with the loopstick signal, they will subtract and you lose some signal. The radio can be repositioned to make the signals add.

If you use a decent sized (larger) antenna, it can pick up more signal than the loopstick because the antenna is physically larger. But since the noise level is higher at MFs (0.3 to 3 MHz) the antenna doesn’t have as much benefit as one at higher frequencies.

Also, there tends to be a lot more man-made noise inside. So putting the antenna outside helps to get away from some of that man-made noise.

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2018-04-21 Three Transistor Audio Amp

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on April 21st, 2018 by - No Comments

From FB group Building Transistor Radios

Both versions have pros and cons. I’m not trying to take sides just make some observations.

#1 (Willie’s) has the 2N3904 and 2N3906 for output Transistors. They can handle only about 100 mA and they easily go into thermal runaway, especially when it gets warm. The 3904 can be replaced with a PN2222A, the 3906 by a PN2907A.

The #2 (Pedro’s) connects the 1.8k bias resistor to the +9V through the speaker. This bootstraps the bias resistor so the output Transistors don’t become current starved as the output approaches +9V. #1 doesn’t have any bootstrap. One disadvantage of #2 is that the speaker must be connected in order to supply bias current. It won’t work with a piezo earpiece.

The excessive idle current in #2 can be reduced by putting a 4.7 to 10 ohm resistor in series with each emitter. The BC337 and BC327 can handle much greater current than the other amp, and are good choices. The C8050 and C8550 are another pair that handle high currents. If you want even more, use the BD135 and BD136.
I’ll post another schematic next.

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2018-04-20 Regen Reflex Receiver

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on April 20th, 2018 by - No Comments

This is from the FB group Building Transistor Radios

This is the schematic of the reflex receiver built by Nick Bastian.

The first transistor is a C9018 NPN RF BJT. The remaining two transistors are 2N3904 NPN BJTs. The coil is a standard ferrite loopstick from a transistor radio.

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2018-04-13 High L, Low C Tank Circuit

Uncategorized
on April 13th, 2018 by - No Comments

From FB group Building Transistor Radios

Nick Bastian
(High L, low C circuit is better) depends on a lot of factors. From what I’ve read, hams try to keep the L low and the C high to give lower wire resistance and higher Q. In this case, the radio has to be very small so that limits the size of the tuning capacitor.

If the Ferrite Loopstick was meant to be left partially uncovered, then a lot of turns could cover it up, I’m assuming that wouldn’t be good. The typical loopstick is wound with Litz wire, I wonder if there is Litz wire fine enough to wind enough for 2.2 mH. It may require a multilayer winding. Considering all of the above and the circuit, my thinking is that high L, low C would not be as good.

And I didn’t mention that the regeneration causes Q multiplication by making up for losses in the tank circuit. That might cancel out much of the difference.

I think that is why hams often build receivers with plug-in coils. They can experiment with different windings to find the optimum coil.

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2018-04-11

Politics
on April 11th, 2018 by - No Comments

From FB group Orange Talk

Dick Paquette

Re: Benghazi and HRC. You’ve become one of the “hysterical backlash” crowd, as this article calls them.

I quote:
“Even though the inquiries found that the State Department leadership in Washington had repeatedly ignored Ambassador Bushnell’s requests for security upgrades, Madeleine Albright didn’t face a hysterical backlash anywhere close to what Hillary Clinton has faced over Benghazi.

For instance, Donald Trump, in his acceptance speech Thursday night at the Republican National Convention, referred to Benghazi, claiming that under her watch, “our ambassador and his staff were left helpless to die at the hands of savage killers.””

One more reason why Trump is as sorry an excuse for president as HRC was a sorry excuse for Sec. of State.

As for your claim that Albright “…didn’t get embassy staff killed…”, this article’s first few paragraphs show that you are clueless and don’t know what you are talking about.

https://www.vox.com/2016/7/22/12241894/benghazi-hillary-clinton-1998-east-africa-embassy-bombings

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2018-04-09 Nuclear Power Is Not Cheap

Politics
on April 9th, 2018 by - No Comments

A comment for the YouTube video

This video portrays nuclear energy as the cheapest. But I can’t see how that can be. They say that nuclear costs $.02 /kWh. I don’t think they count all the energy inputs and costs. With oil we have a “Well to Wheels” measure of all costs, from well to the wheels. The nuclear fuel is sold to utlities at a huge subsidy by the US government. That’s hiding the fact that it is costing the taxpayers a huge amount to process the uranium for fuel.

Also, the cost of storing spent fuel must be included. It can’t be stored in containers for years because it generates too much heat. It must be stored underwater in pools cooled to prevent the water from boiling away and the fuel turning into another Fukushima.

Another problem with nuclear power is the utilities are unwilling to spend ten billion or more to build a power plant. Altogether the various issues with nuclear power have prevented nuclear power from building new plants for decades. And as was said, it is not renewable energy.

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2018-04-08 Gun Rights Not Being Stripped

Politics
on April 8th, 2018 by - No Comments

From FB group Orange Talk

Rudy Castillo
The problem back then with the Patriot Act was the strong opposition to it by EFF and others. But there were enough people with the realization that something had to change if another 9-11 was to be prevented. It was not a matter of “if we allow giving in an inch, they’ll take a mile”. Life is not a matter of black and white, there are many shades of gray. Long ago, the gangsters carried Tommy guns around in a violin case. The Feds took away that right, so now it’s illegal to own a machine gun without a license.

But the gun makers and sellers have their business at stake. They are going to fight any changes with all they have, money, lobbying, and *most of all* the indoctrination of the public that their Second Amendment rights are being stripped. This basically is the same thing happening with every mass shooting.

If those who have so much at stake don’t come up with an equitable solution, more and more of the people of this country are going to take one side or the other, and there are a lot more people willing to take sides with those who want guns banned. This scares the hell out of gun rights advocates.

I own a gun and I was once like the gun rights advocates. But that was before I found out there were so many people dying from guns. One of my coworkers committed suicide with a gun. I thought about that a lot. Until you and others experience this, it is most likely that you and others will not change. I feel that there is little that I can say that will change anyone’s mind. 😖😞

Rudy Castillo
Exactly. I’m too old to see that, but eventually cars driven by humans will be difficult to see, and every car will be autonomously driven.

But you need some form of transportation to get to work every day, shopping and vacations etc. You seldom if ever need a weapon. In ’66 I watched the smoke from the Riots rising west of my house. If ever there was a time when we thought we would need a gun, it was then, when widespread looting was going on. That was a scary time.
Since those riots, there have been more killed by guns in the US than all the wars combined. More than a million and a half people. The latest gun death statistics are horrible. In 2016, 33 thousand died. And this can (and will) be drastically reduced by doing what Australia has done.

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2018-04-06 Stopping Telemarketer calls

Telephone
on April 6th, 2018 by - No Comments

From FB group Bell Telephone of the…

It’s possible [to stop telemarketing calls]. There are some gotchas, though. One I see is a nonselective rejection of unknown incoming calls is the emergency services, etc., wouldn’t be able to contact you. If the school had a threat and had to call parents, they would be blocked. I don’t see why it would be a big deal, because reverse 911 service was not around before and there wasn’t a problem. Every kid has a phone so they could make the call. Or the emergency could spoof the kid’s number (legally with permission).

I think the biggest complainers would be political, poll taking, charitable and non-profit agencies. They would lose all contact. But I don’t see why some of these couldn’t replace voice contact with text contact.

No More Robo made the headlines a while ago, but at that time it was only for landlines. Now, the landlines are being abandoned. I haven’t checked to see if it’s now available for wireless.

I checked and No Mo Robo is available for wireless but it’s $2 a month and the reviews rated it as not worth it, gave it 2.5 stars, that’s bad. 👎

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