Kindess of Strangers

In the closing moments of Tennessee Williams’ A Streetcar Name Desire, Blanche DuBois utters her most memorable line, “Whoever you are, I have always depended on the kindness of strangers.” Amateur radio operators are sometimes like that.

hk-5aI recently came into possession of a HamKey HK-5A keyer (see right). HamKey has been out of business for many years, so I had to depend on the kindness of strangers to find any kind of documentation for the unit.

Fortunately, Google and the hams out there came through. I Googled “HamKey HK-5A” and found a thread on an eHam forum. In the thread, N5RDN offered to make a copy of his manual for KW4MM. I emailed Rob, N5RDN, and a PDF of the manual appeared in my inbox this morning.

Thanks, Rob!  I now offer the HK-5A-manual here for anyone who needs it.

New clock accurate to within 1s every 300 million years

14PML013_f2_jefferts_heavner_LR

NIST physicists Steve Jefferts (foreground) and Tom Heavner with the NIST-F2 “cesium fountain” atomic clock, a new civilian time standard for the United States. Credit: NIST

The U.S. Department of Commerce’s National Institute of Standards and Technology (NIST) has officially launched a new atomic clock, called NIST-F2, to serve as a new U.S. civilian time and frequency standard, along with the current NIST-F1 standard.

NIST-F2 would neither gain nor lose one second in about 300 million years, making it about three times as accurate as NIST-F1, which has served as the standard since 1999. Both clocks use a “fountain” of cesium atoms to determine the exact length of a second.

NIST scientists recently reported the first official performance data for NIST-F2,* which has been under development for a decade, to the International Bureau of Weights and Measures (BIPM), located near Paris, France. That agency collates data from atomic clocks around the world to produce Coordinated Universal Time (UTC), the international standard of time. According to BIPM data, NIST-F2 is now the world’s most accurate time standard.**

NIST-F2 is the latest in a series of cesium-based atomic clocks developed by NIST since the 1950s. In its role as the U.S. measurement authority, NIST strives to advance atomic timekeeping, which is part of the basic infrastructure of modern society. Many everyday technologies, such as cellular telephones, Global Positioning System (GPS) satellite receivers, and the electric power grid, rely on the high accuracy of atomic clocks. Historically, improved timekeeping has consistently led to technology improvements and innovation.

Read more and watch video …

Read background information about how NIST F-2 Works and watch animation …

From my Twitter feed: clear-top boxes, SDR, HSMM

LA3ZA's avatarSverre Holm, LA3ZA @LA3ZA
Show off your project in a clear top tin la3za.blogspot.com/2014/02/show-o…

roteno's avatarVictor Laynez @roteno
Fun little radio housing. pic.twitter.com/QtmCw2smuW

DIYEngineering's avatarDIY Engineering @DIYEngineering
Using SDR to Read Your Smart Meter – [BeMasher] was dissatisfied with the cost of other solutions to read his smar… ow.ly/2EcLiT

kc5fm's avatarkc5fm @kc5fm
An Old Buzzard’s Guide to Getting Started with HSMM-Mesh bit.ly/1eL1cQg #ARRL #hamradio

ARRL Board Requests Member Comments About Digital Modes

ARRLSB QST @ ARL $ARLB007
ARLB007 ARRL Board Requests Member Comments About Digital Modes

ZCZC AG07
QST de W1AW
ARRL Bulletin 7  ARLB007
From ARRL Headquarters
Newington CT  March 3, 2014

To all radio amateurs

SB QST ARL ARLB007
ARLB007 ARRL Board Requests Member Comments About Digital Modes

At the January 2014 ARRL Board of Directors meeting, a resolution was passed which asked for member feedback and input pertaining to the increasing popularity of data modes. The information gathered by  this investigation is to be used by the HF Band Planning Committee of the Board as a means to suggest ways to use our spectrum efficiently so that these data modes may “compatibly coexist with each other.”  As per the resolution, the ARRL Board of Directors is now reaching out to the membership and requesting cogent input and thoughtful feedback on matters specific to digital mode operation on the HF bands.

The feedback may include, but is not limited to, the recent proposal the ARRL made to the FCC, RM 11708, regarding the elimination of the symbol rate restrictions currently in effect.  A FAQ on RM 11708 can be found on the web at, http://www.arrl.org/rm-11708-faq .

The Board of Directors believes that member input in the decision making process is both valuable and important as well as fostering a more transparent organization.  It is to this end that we open this dialogue.

Comments must be received no later than March 31, 2014 to be included in the Committee’s report to the Board at the July 2014 ARRL Board of Directors meeting. Please e-mail your comments to: HF-Digital-Bandplanning@arrl.org

Concerned members may also contact their Division Director by mail, telephone or in person with any relevant information.

From my Twitter feed: Antique wireless, Nuclear Summit special event

K7AGE's avatar @K7AGE
AWA GATEWAY available #hamradio antiquewireless.org/uploads/1/6/1/… pic.twitter.com/NoI7dkksmW

DIYEngineering's avatarDIY Engineering @DIYEngineering
Call for Hams and Hackers: Welcome ICE/ISEE-3 Home – ISEE-3, one of America’s most dedicated space exploration … ow.ly/2DSJMz

PD0MV's avatarPD0MV@PD0MV
#PD6NUKE – For All Ham Operators world wide pic.twitter.com/tmHZDuCQAOStory image

From my Twitter feed: SDR, spider coils, smart scope

vielmetti's avatarEdward Vielmetti @vielmetti
decoding radio digital modes without a radio, using WebSDR and fldigi /cc @kb6nu #hamr bit.ly/1o678qG

mike_n8wc's avatarMike Comer @mike_n8wc
@kb6nu great info! Back to radio after several years. Enjoy how the internet has enhanced enjoyment of a great radio hobby.

AK6L's avatarRobert Liesenfeld @AK6L
Taught myself PostScript and wrote a template generator for making spider-wound coils. Inspired in part by .@vk2zay. github.com/xunil/spider_c…

DH1TW's avatarTobias @DH1TW
“SmartScope – Kickstarter campaign for an open source 100MS portable oscilloscope #hamradio #diy feedly.com/k/1gr8jQm

LC100 LC meter seems like a good deal

I recently bought an LC100A LC meter from eBay, like the one shown below. If you search eBay, you’ll find them on sale anywhere from $20 to $40. Yesterday, I finally got around to playing with it a little.

lc100

To power the device, you need to supply +5V. It comes with a cable that has a USB connector on one side and a power connector on the other. Obviously, it’s meant to be powered by a USB port. I used a power adapter that I purchased to charge an iPod. It worked great.

As a quick test, I measured the capacitance of ten 0.33 uF caps that I purchased for a project. I first measured the capacitance with the LC100A and then with the fancy-schmancy Keithley 2110 that I purchased about a year ago. Below are the results:

LC100 2110
1  .35 .339
2  .33 .326
3  .33 .318
4  .33 .322
5  .33 .324
6  .34 .328
7  .34 .330
8  .34 .329
9  .34 .330
10  .33 .316

Now, this wasn’t a very scientific test, but I am pleased with the results. I also measured the value of some 330 uH chokes that  I had. They all measured between 315 and 320 uH.

So, all in all, I think this is a good deal for the money. I’m looking forward to using it on some of my projects. The next step is to find a box to put this in. I’m surprised that no one seems to have found one yet.

2014 Tech study guide: Basic repair and testing

The addition of T7D12 is the only change to this section…Dan

The most common test instrument in an amateur radio shack is the multimeter. Multimeters combine into a single instrument the functions of a voltmeter, ohmmeter, and ammeter. Voltage and resistance are two measurements commonly made using a multimeter. (T7D07)

You use a voltmeter to measure electric potential or electromotive force. (T7D01) The correct way to connect a voltmeter to a circuit is in parallel with the circuit. (T7D02) When measuring high voltages with a voltmeter, one precaution you should take is to ensure that the voltmeter and leads are rated for use at the voltages to be measured. (T7D12)

An ohmmeter is the instrument used to measure resistance. (T7D05) When measuring circuit resistance with an ohmmeter ensure that the circuit is not powered. (T7D11) Attempting to measure voltage when using the resistance setting might damage a multimeter. (T7D06) What is probably happening when an ohmmeter, connected across a circuit, initially indicates a low resistance and then shows increasing resistance with time is that the circuit contains a large capacitor. (T7D10)

An ammeter is the instrument used to measure electric current. (T7D04) An ammeter is usually connected to a circuit in series with the circuit. (T7D03)

In addition to knowing how to make electrical measurements, knowing how to solder is an essential skill for amateur radio operators. Rosin-core solder is best for radio and electronic use. (T7D08) A grainy or dull surface is the characteristic appearance of a “cold” solder joint. (T7D09)

2014 Tech study guide: receivers, transmitters, and transceivers

This section was changed quite a bit. It used to include four block diagrams, but the question pool committee eliminated all of them. Bravo! Dan

In the early days of radio, amateur radio operators used separate receivers and transmitter units. Nowadays, however, most use radios called transceivers. A  transceiver is a unit combining the functions of a transmitter and a receiver. (T7A02)

There are many different types of transceivers. A multi-mode VHF transceiver is the type of device that is most useful for VHF weak-signal communication. (T7A09) Instead of purchasing a multi-mode VHF transceiver, many amateurs use a transverter to convert the signals from their HF transceiver to the VHF, UHF, and even microwave bands. For example, a device that would take the output of a low-powered 28 MHz SSB exciter and produces a 222 MHz output signal is a transverter. (T7A06)

Many, if not most, new amateurs purchase a handheld transceiver, sometimes called a “handie-talkie,” or HT, as their first transceiver. One disadvantage of of using a handheld transceiver is that the maximum output power is generally only 5 W, and because of this, they have limited range. To increase the low-power output of a handheld transceiver, and therefore its, range, you can use an RF power amplifier. (T7A10)

When talking about a transceivers specifications, we still refer to its receiver and transmitter. The two most important specifications for a receiver are sensitivity and selectivity. Sensitivity is the term that describes the ability of a receiver to detect the presence of a signal. (T7A01) The term that describes the ability of a receiver to discriminate between multiple signals is selectivity. (T7A04)

To improve the sensitivity of a receiver, you can use an RF preamplifier. An RF preamplifier is installed between the antenna and receiver. (T7A11)

Most HF transceivers have some version of a superheterodyne receiver. In a superheterodyne receiver, we first convert an incoming radio signal from its frequency to an intermediate frequency, or IF. The circuit that does this is the mixer. A mixer is used to convert a radio signal from one frequency to another. (T7A03)

When transmitting, we want to generate an RF signal with a specific frequency. To do that, we use an oscillator. Oscillator is the name of a circuit that generates a signal of a desired frequency. (T7A05)

To transmit a voice signal we have to combine an audio frequency signal from the microphone with the RF carrier signal generated by the transmitter. Modulation is the term that describes combining speech with an RF carrier signal. (T7A08) Modulators use a type of mixer circuit to accomplish this process.

2014 Tech study guide: operating controls

Question T4B12 about the function of automatic gain control was added to this section…Dan

To properly operate a transceiver, you need to know how to use the controls. Perhaps the most important transmitter control is microphone gain. If a transmitter is operated with the microphone gain set too high, the output signal might become distorted. (T4B01)

You also need to know how to set the operating frequency of your transceiver. The keypad or VFO knob can be used to enter the operating frequency on a modern transceiver. (T4B02) A way to enable quick access to a favorite frequency on your transceiver is to store the frequency in a memory channel. (T4B04)

A common receiver control on VHF/UHF transceivers is the squelch control. The purpose of the squelch control on a transceiver is to mute receiver output noise when no signal is being received. (T4B03) If set too high, then you will not be able to hear low-level signals.

Another common setting on VHF/UHF transceivers is the offset frequency. This is especially important when operating repeaters. The common meaning of the term “repeater offset” is the difference between the repeater’s transmit and receive frequencies. (T4B11)

A common receiver control on HF transceivers is the RIT control. The term “RIT” means Receiver Incremental Tuning. (T4B07) The receiver RIT or clarifier are controls that could be used if the voice pitch of a single-sideband signal seems too high or low. (T4B06)

Another common control on a receiver is the automatic gain control, or AGC. Its function is to keep received audio relatively constant. (T4B12) This is important because HF signal strengths can vary widely. and that can cause audio levels to vary widely as well.

HF transceivers are often equipped with a variety of different filters. The advantage of having multiple receive bandwidth choices on a multimode transceiver is that it permits noise or interference reduction by selecting a bandwidth matching the mode. (T4B08) For example, 2400 Hz is an appropriate receive filter to select in order to minimize noise and interference for SSB reception. (T4B09) 500 Hz is an appropriate receive filter to select in order to minimize noise and interference for CW reception. (T4B10)