Battery Safety

No matter what kind of battery you are using they can be dangerous. All contain toxic materials and stored energy. Lead-Acid batteries demand the most respect. They are heavy, contain acid and can deliver very high currents that can start fires and produce serious burns. The old practice of removing your wedding ring when working around lead acid batteries is still a good rule. Documented stories tell of battery workers losing their ring finger when they accidentally got their wedding band across a Lead-Acid battery terminal pair.

A Closer Look at Inverter Generators

By: Kirk A. Kleinschmidt, NTØZ

Inverter Generator Basics
Unlike conventional generators, which typically use a two-winding core that must turn at 3600 RPM to produce 120 V ac power at 60 Hz, inverter generators produce multiple-phase ac power at high frequencies, which is electronically “converted” to dc, then “inverted” back to rock-solid, low distortion, 120 V, 60 Hz ac. Because an inverter generator can draw more power per revolution from the generator core (thanks to several hundred overlapping sine waves per revolution), the core doesn’t need to operate at a fixed speed to maintain regulation. Inverter generators are lighter, quieter, and more fuel efficient because generator speed is automatically adjusted to match load conditions.

Inner Workings

A conventional generator rotates two large coils inside its core, and each full engine rotation produces one complete ac sine wave. By design, the engine must spin the generator at 3600 RPM to produce the desired ac output. If, because of varying loads, the generator spins faster or slower, the voltage and frequency of the output vary in step. In an inverter generator, the core uses multiple coils and multiple magnets. Each full rotation of the engine produces more than 300 three phase ac sine waves at frequencies up to 20 kHz, which produces more electrical energy per engine revolution. A microprocessor-controlled inverter module converts the high-frequency ac to dc (about 200 V in at least one unit) before “inverting” it back to clean, stable 120 V, 60-Hz ac power. Typical inverter generator regulation specs are 3% voltage, 1% frequency and 3% sine wave distortion. That’s essentially “power company” ac in a hand-carried unit!

Sound Design

A compact, tightly regulated ac power source just wouldn’t be quite so handy if it sounded like a jet engine. To minimize noise and vibration, manufacturers designed extra large internal exhaust mufflers, multi-chambered inner structures that isolate intake air from output exhaust, innovative internal cooling and air transport fans and enclosures that use unconventional laminates. The generators are compact and “friendly” looking, but the internal construction is carefully tailored to minimize sound and provide adequate cooling. If you look closely, you’ll notice that, unlike typical construction site generators that use open frame designs that let everything “hang out,” the smaller inverter gens are completely enclosed. Instead of using a single layer of plastic for the outer shell, at least one manufacturer sandwiches a layer of sound and vibration-dampening foam between two thin layers of plastic. This dramatically reduces sound levels and prevents the enclosure from “resonating” with the whirring and rotating internal parts and exhaust notes.

Size and Efficiency

If you’re wondering whether portable generators have been getting smaller these days, you’re right! Thanks to relentless design efforts and the fact that inverter generators are some 20% more efficient than their conventional counterparts, engines, generator cores and enclosures have been shrinking, in size and weight.

RFI

Generators can create RFI so you may need to put a filter on the line.  Check out the 2012 June issue for a review of 4 small generators.

Four Field Day Generators

https://www.youtube.com/watch?v=rOH7Ze7wreQ

Battery Calculator

This is the Battery Calculator that I created in Google Sheets.  I talked a little about this during our NET.  Please let me know if you see any mistakes.

https://docs.google.com/spreadsheets/d/12EtWr0rc4qimsTGhWJgs2kswmifXUpTwSUx6Ioix18s/edit?usp=sharing

Thanks,

Mat

In-person Meeting

This Quarters in-person meeting will be at West Valley City Hall on February 25th. We will take a tour of the EOC there and then do a training on public service events and a communications exercise. if you have an HT please bring that with you for the exercise.

We will meet in the Foyer of the City Hall and then go on the tour. If you are late or get lost please contact me KG7RZX on the 146.700 - 100 hz repeater and I will talk you in.

We expect to start at 19:00 sharp and end about 20:30

Our regular Net that night will be cancelled.

We look forward to seeing all of you at this meeting.

Jason KG7RZX

Technician Class

You can register here: https://goo.gl/RN5DKw

Hamfest volunteer meeting cancelled

Dear Friends in Amateur Radio,

Due to sudden, unforeseen circumstances, the meeting of volunteers for The Great Salt Lake Hamfest tomorrow is CANCELLED.

I am grateful to everyone that put this meeting on their schedules and those that emailed to say they will help but wouldn't be able to attend the meeting.  I will let you know when this meeting is re-scheduled.

If you receive this more than once, it is likely that you responded to me by email.  I just want to be sure you get this message.

Please forward this to those whom you might have contacted.

I will be OUTSIDE the PSET building  from 8:15 to 9:15 a.m. tomorrow, in case someone shows up that is not on this email list or that didn't open their email before tomorrow's meetings.

Gratefully yours,

Susan Smith

KJ7ABC

Tonight's Net & Training 2/4/2016

Tonight we would like all operators to check in using a HT. we will be checking in on an ht all month so get those batteries charged.

Additionally tonight's training topic is on repeaters. So put your questions in the comments below so that we can answer them.

See ya on the net.

--JB