I’ve been challenged by a number of fairly costly things going wrong lately, from expensive drone repairs, to expensive aircraft repairs, to now what seems to be a possible expensive ham radio repair………….
………but then
But then……
Category: Uncategorized
Ameritron AL-811 Repair: Plan of Works
For an introduction to this , go to my previous post Ameritron AL-811 Purchase and Repair
WARNING: LINEAR AMPLIFIERS CAN RETAIN LETHAL VOLTAGES EVEN WHEN TURN OFF AND UNPLUGGED- YOU HAVE BEEN WARNED
THE HISTORY:
I purchased an Ameriton AL-811 that was in lovely shape cosmetically but seemed to have some issues.
Shortly after my first use, it blew a hole in the side of an 811a. This valve blew while using on 80m. Afterwards, I required a setting of zero load which leads me to think a I have a failed padding capacitor. I have several on order and will test the old ones soon.
Downstream affects of this or possibly other events in the amplifier’s past seem to be
- overheating of parasitic suppressor board leading to detachment of braid to tube cap- re-soldered and board components tested fine despite evidence of overheating. This board has the new 5 turn inductors to reduce overheating.
- confirmed damaged plate choke 9arc). needs replacement or rewinding
- possible leaky ALC isolation capacitor- I have one on order
- damaged blocking capacitor- I have two 15kV units on order
- possible meter shunt resistors (330 ohm and 180 ohm specified) are undervalue. Metal Film Resistors tend to go low when overheated. This is due to the manufacturing process which can lead to resistors becoming semi-conductors due to overheating altering their makeup. – I have replacements ready to put in 1/2watt replacing 1/4 watt
One other small issue, one of the riv-nuts (captive nut) that holds the upper cover on is detached.
Viking Ranger II Restoration
If you have been following my Twitter (see the bar on the right), you will know that I have been restoring a Johnson Viking Ranger II. As many hams know, my life went into a big spiral when my business and marriage collapsed. I ended up homeless. Eventually I moved to Sydney and started all over again. I had however saved some of my favourite radio projects and kept them in storage. One of them was a Johnson Viking Ranger II. It was in beautiful condition but more recently something has damaged the paint in a few places. I suspect something was spilled on it in storage. Electrically it needed some work. I had replaced the audio driver transformer but since doing so the rig had been in storage and I wasn’t sure if I had finished that job, or what other work was required or undertaken all those years ago, so it was quite a bit of work to get it sorted. I also had to restore n Astatic D104 on a TUG-8 stand.
I am very happy to have this radio going as it is AM and CW only, two of my favourite modes. I am looking forward to getting the new 811 valves (tubes) and eventually the new 572bs for my Ameritron AL-811 so that I can operate with full legal power on AM.
I look forward to many CW and AM contacts on this rig. If you too are interested in old rigs and AM, check out the Ancient Modulators Club of Australia on Facebook.
The Shack Reorganisation Never Ends
I’ve only just settled in here in my new small country town but I wasted no time in getting an antenna in the air. I had a few QSO’s and then got busy with both flying and work commitments. Having been unemployed, my budget is also tight but I did have a little something that I’d been longing to setup and just couldn’t in Sydney. It’s in the bottom right of the photo.
This of course required another reorganisation of the shack, particularly since I’ve been having some issues on some bands with RF feedback. The KRK studio monitor that I restored suffers from RF interference, or so I thought (it’s a well published issue), but turns out it was actually the Behringer 802 mixer I use to provide microphone input to multiple radios and audio out from multiple radios, to the KRK, that was the issue.
A relocation of the mixer, some grounding and some toroids and clip-on ferites dealt with most of it. The antenna I am using was made for WWF and SOTA (a ZS6BKW) was made from measurements and was never optimised. I sought to do that but found the ladder line a little short. I added some more wire to each leg of the dipole which helped a bit. more- no more RF in the shack! I’ll get around to building a new antenna at some point. First I have to get some poles to raise the antenna higher than the 8 metres (at the apex) that it currently is.
I’ve just placed a hand mic on the Drake while I rebuild the interface for the Heil PR781
Progress at the New QTH
While I wait for AMC and ACMA to sort out the mess with my VK2 callsign, I’ve been busy. It took me quite some time to get the APRS fill-in digi/igate setup. I forgot so much about configuring the TinyTrack4, as I was in Sydney using my Kenwood D700 as a digi for a while. Anyway I got that sorted after a day of work and then set about setting up the weather station. Unfortunately something caused the Davis Vantage Vue ISS unit to stop sending data to the console. I thought perhaps it had a flat battery, so I replaced that , but no success. I could not get the green LED to flash at all. I definitely could not see any reception on the console and could get no response from long or short presses on the button under the ISS. I double checked the battery voltage, then took the unit apart hoping it was something simple. Unfortunately I could see nothing. Perhaps, I thought, I’d fried the transmitter with RF from the HF radio antenna. I left the unit sitting on the bench overnight with the battery out of it and returned to it this morning. I inserted the battery and got an instant response. Go figure! So I’ve set the unit up temporarily on a low pole to see how it goes for a few days before putting it up high- this time away from the HF antenna.
For the first time in a few years I had some QSOs on CW. I’m a bit rusty but fortunately the ops were kind. Thanks to VK2DVA and VK4IAN. I note the ZS6BKW that I hastily constructed, needs a bit of tuning. That will have to be a job for later in the week, as I’m going soaring in the few days I have left before I have to go back to work.
False Accusations
There are a number of people who will vouch for not only my operating professionalism but also my integrity.
Getting Started, RaspberryPi, APRS, Xastir Part 2
Let’s get our geek on girls.
So you got your RaspberryPi, you installed the OS from your NOOBS SD card or manually, as per Part 1, now what? Well there are lots of great things you can do, but I’m going to help you set up APRS.
You will need
RaspberryPi with operating system installed.
Keyboard and mouse and HDMI screen and HDMI cable
A Terminal Node Controller such as TNCPi, or a radio with a build in TNC, like the Kenwood TM-D700 series and a suitable cable to connect your TNC to the pi if the TNC is not an add on board, commonly referred to as a hat.
APRS, variously known by a few names is an Automatic Packet Reporting System, commonly used to show locations of objects and for messaging, typically on VHF and UHF but also HF. You can see APRS in action by entering the name of your city into the search box at www.aprs.fi. You can adjust the time span to see movement of the various objects over a span of time. Below is my city of Sydney (VK2) for the previous 24 hours. That moving house is a worry 🙂
APRS can also be used to show and share weather at your location by integrating your APRS with your weather station should you have one. I will explore that topic later.
Here is my weather station on APRS
So let’s get started
Your raspberryPi is turned on, connected to mouse, keyboard and an HDMI screen.
Open up the terminal, remember it is the black icon >_ or use the keystrokes mentioned in Part 1 Cntrl-Alt-T.
Into terminal type the following, one line at a time- ignore lines preceded with #, these are my comments
# You should always update before installing new software
sudo apt-get update
# install the xastir package
# hit ‘Y’ when prompted – it installs lots of dependencies
# so will take some time
sudo apt-get install xastir
# now start X-windows if you’re not already in the graphic user interface
startx
Once you have xastir installed and X running, you will find xastir listed under internet on the newer versions of the OS– alternatively open up a terminal window and start the program by typing xastir.
You will be prompted for your callsign and location etc. – this is fairly self explanatory but the xastir website will be able to help. One thing I will say is that the first thing you’re likely to want is a better map – go Map > Map Chooser, select the four Online/OSM_cloudmade_3.geo maps for Open Streetmap, and deselct the default worldhi.map. It will take a bit of time for the maps to be downloaded but they’re very good. You will also need to know your latitude and longitude in degrees and decimal minutes not degrees minutes and seconds or have a GPS connected as well (more on that later). You can find your lat/lon on Google maps with a right click on your location. You can convert to various d,m,s decimal degrees etc at many conversion sites like https://www.directionsmag.com/site/latlong-converter/
Connecting a Terminal Node Controller (TNC)
There are many TNCs available but I use a Kenwood TM-D700. It and the D710 have a built in TNC. Follow the radio manual instructions and set the TNC to serial, not KISS.
If you are using another TNC, follow the instructions to connect it to the Pi and to set it to serial TNC mode.
We will explore other TNCs in Part 3.
For those TNCs connected by USB, you will need a cable to connect to the USB port on the Pi. You will definitely need a special programming/serial cable to connect your D700 series radio. Don’t fool around with serial USB converters they will not work, Use this cable if you have a D700 series radio. It is the only one that I have found that works with the Kenwood radios
So let’s get data coming in from our TNC.
First connect your cable to both TNC and Pi. Find the USB port that it is connected to with this command in terminal
dmesg | grep tty
#That | key is hard to find on some keyboards.
#On my Apple keyboard it is on the far right and requires shift. :-).
You should see something like this
Note the second last line – My FTDI cable is ttyUSB0, yours may be different.
Now go to Xastir Interface > Interface Control and click ‘Add’. Select ‘Serial TNC’, set /dev/ttyUSB0 as the port or whatever you found yours was with the dmesg command, change the baud rate to 9600 and leave the rest as default for now, although you might want to change tnc-startup.sys for one matching your TNC from the list in /usr/share/xastir/config. Mine is tnc-startupD700.sys
Click ‘OK’ and hopefully, you’ll be able to select your new interface and start it – ‘DOWN’ will change to ‘UP.
For debugging, View > Incoming Data provides some very useful insight into data flowing to and from the TNC or other interfaces.
If you want to receive data from the Internet, add an ‘Internet Server’ interface. You’ll need to get a passcode to match your callsign (google APRS passcode generator for clues,) and find your most convenient aprs host and port. Again, the ‘Incoming Data’ window can help with debugging. My aprs server is first.aprs.net.au. Take a look here for yours http://www.aprs-is.net/aprsservers.aspx
At this point, consult existing XASTIR resources to refine your configuration. Good luck!
Getting Started RaspberryPi, APRS, Xastir Part 1
This blog post is intended for hams beginning with RaspberryPi, who want a great ham radio project. It was initiated by a query on the YL Op Net a women’s only net that happens 0000 utc Fridays on the ALARA Conference Server.
The first thing you need to do is get yourself a Raspberrypi. If you are brand new to RaspberryPI you may wish to buy all of the bits and pieces you need straight up as that is often the cheapest option, unless you have some stuff laying around, like keyboards and mouse and HDMI monitor or TV. There are some great complete kits on eBay and elsewhere.
While you are at it, why not get the preinstalled operating system on an SD card and save yourself the process of setting up your own SD card. This is a good idea until you get more familiar with the pi. Otherwise you need SD card formatting software and a range of other tools and a fast SD card. The RaspberryPi 3 uses micro SD whereas the earlier models use normal SD cards. The prepackaged OS install is called NOOBS. If you want to go it alone, try this resource for a how to
https://www.raspberrypi.org/documentation/installation/noobs.md
To get started with RaspberryPi, one of the best things you can do is find a likeminded group of people either physically located near you or via social media. Most RaspberryPi’s are initially setup to run a Linux operating system called Raspian. If you have not ever used command line interface or Linux before, it will be very useful to have some help on hand, as it can be daunting initially. The new operating system on the RaspberryPi has a great Graphic User Interface (GUI) but because of the inability to log in as root and for other reasons of convenience, you will do most to your work in the command line. Command line looks like this-
The above is a great example because one of the first commands you will need to know is sudo. Think of it as “superuser do.” When you log in to a pi as you can see from the above image, you are logged in as pi. eg. pi@raspberrypi. Now the user named pi is not a superuser, not an administrator, probably so we can’t mess things up too much. So if you want to do something like install or remove software or update the system, you have to tell the pi that you wish to do that as a superuser, hence sudo. You will quickly get used to preceding most commands with sudo.
Plug your keyboard and mouse and HDMI cable connected to a screen in and turn the screen on- you can use a television. Put the SD card in the pi and connect the power. There is no on/off switch. I am going to assume you have access to a HDMI cable and a monitor, otherwise you have to run the pi headless which I will describe later. When you get your pi and start it up, if you are using the latest version of the operating system, it will load the GUI. Do not connect power hungry devices to the USB- you will need a powered hub if you do.
You will need to access the command line interface, which you do by opening the terminal. Click on the black icon with this symbol >_ in the top menu bar or type Ctr+Alt+T. The very first thing you need to do before you do anything else is update and upgrade the software that is installed. So you will get to use the command line straight up. Later on when you are running headless, you could copy and paste from this blog and save some time, but for now, just type the following commands
sudo apt-get update
Then wait for the pi to complete the tasks and select y or yes if asked. Then type
sudo apt-get upgrade
This one will take quite a bit longer to run and will require interaction.
Now you should be ready to get started with installing Xastir. Bear in mind that this blog will describe using Xastir connected to a Kenwood TM-D700 which has a built in Terminal Node Controller, (TNC) If your radio does not have a built in TNC, you will need to get one. There are a few made especially for the RaspberryPi, like this one.
73
de VK2KIM
Inspirational YLs
Are you looking for ways to inspire young women to be involved in science and amateur radio? These inspirational women may be the answer.
Female Space Hams
https://en.wikipedia.org/wiki/Tamara_E._Jernigan
Tamara E. Jernigan (USA) formerly KC5MGF. Jernigan attended Santa Fe High School in Santa Fe Springs, CA. She graduated in 1977. Jernigan attended Stanford University, where she earned a B.S. degree in physics in 1981, an M.S. in engineering science in 1983. At the University of California, Berkeley, she received an M.S. in astronomy in 1985. In 1988 she was awarded a Ph.D. in space physics and astronomy from Rice University.
She entered the NASA Astronaut Corps in 1986 and retired in 2001. Her first trip to space was on June 5, 1991.[1] She flew on five Space Shuttle program missions (three on Columbia and one each on Endeavour and Discovery) and logged 1512 hours in space. In her last mission on Discovery in 1999, she performed an extra-vehicular activity for 7 hours and 55 minutes.
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http://www.spacefacts.de/bios/international/english/bruemmer_renate.htm
Renata Luise Bruemer (Germany) DB5PL Studied mathematics and physics at the Munich University; Ph.D. in meteorology from University of Miami, Florida, 1986; research scientist at University Corporation for Atmospheric Research, Boulder, Colorado; was selected as backup for STS-55 (D-2 mission).
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https://en.wikipedia.org/wiki/Yvonne_Cagle
Born in West Point, New York, Yvonne Cagle (USA) formerly KC5ZSV graduated from Novato High School in Novato, California. She received her bachelor’s degree in biochemistry from San Francisco State University in 1981, and a doctor of medicine degree from the University of Washington in 1985. She completed a transitional internship at Highland General Hospital in Oakland, California in 1985 and received a certificate in Aerospace Medicine from the School of Aerospace Medicine at Brooks Air Force Base, Texas, in 1988. She then went on to complete a residency in family practice at Ghent FP at Eastern Virginia Medical School in 1992 and received certification as a senior aviation medical examiner from the Federal Aviation Administration in 1995.
Cagle retired from the United States Air Force with the rank of Colonel in 2008. As a commissioned medical officer in the USAF Cagle served as Air Force Medical Liaison Officer for STS-30, before she became a NASA astronaut. She worked as medical doctor at NASA’s Occupational Health Clinic from 1994 to 1996. In 1996 she was selected for astronaut training by NASA.
Yvonne Cagle was a member of the Astronaut Class of 1996 (NASA Astronaut Group 16). She is currently assigned to Johnson Space Center’s Space and Life Sciences Directorate.
Dr. Cagle is also an advisor for NASA’s Flight Opportunities Program (originally named CRuSR – Commercial Reusable Suborbital Research Program). Currently Dr. Cagle is on faculty and serves as the NASA liaison for exploration and space development with Singularity University. During the workshop, Dr. Cagle was embedded with the crew as a crew training consultant and advisor, providing insights and feedback to both crew and study team from the viewpoint of an astronaut, flight surgeon, space development expert, and science liaison.
She has recently been selected reserve crew for Hawai‘i Space Exploration Analog and Simulation (HI-SEAS), which is part of a study for NASA to determine the best way to keep astronauts well nourished during multiple-year missions to Mars or the moon. Furthermore, Dr. Cagle is also listed as an honorary member of the Danish Astronautical Society.
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https://en.wikipedia.org/wiki/Tracy_Caldwell_Dyson
Tracy Caldwell Dyson (USA) KF5DBF born Tracy Ellen Caldwell; August 14, 1969 is an American chemist and NASA astronaut. Caldwell Dyson was a Mission Specialist on Space Shuttle Endeavour flight STS-118 in August 2007. She was part of the Expedition 24 crew on the International Space Station between April 4, 2010 and September 25, 2010. She has completed three spacewalks, logging more than 22 hrs of EVA including work to replace a malfunctioning coolant pump.
As an undergraduate researcher at the California State University, Fullerton (CSUF), Caldwell Dyson designed, constructed and implemented electronics and hardware associated with a laser-ionization, time-of-flight mass spectrometer for studying atmospherically relevant gas-phase chemistry.
Also at CSUF, she worked for the Research and Instructional Safety Office as a lab assistant performing environmental monitoring of laboratories using hazardous chemicals and radioactive materials, as well as calibrating survey instruments and helping to process chemical and radioactive waste. During that time (and for many years prior) she also worked as an electrician/inside wireman for her father’s electrical contracting company doing commercial and light industrial type construction.
At the University of California, Davis, Caldwell Dyson taught general chemistry laboratory and began her graduate research. Her dissertation work focused on investigating molecular-level surface reactivity and kinetics of metal surfaces using electron spectroscopy, laser desorption, and Fourier transform mass spectrometry techniques. She also designed and built peripheral components for a variable temperature, ultra-high vacuum scanning tunneling microscopy system.
In 1997, Caldwell Dyson received the Camille and Henry Drefus Postdoctoral Fellowship in Environmental Science to study atmospheric chemistry at the University of California, Irvine. There she investigated reactivity and kinetics of atmospherically relevant systems using atmospheric pressure ionization mass spectrometry, Fourier transform infrared and ultraviolet absorption spectroscopies. In addition, she developed methods of chemical ionization for spectral interpretation of trace compounds. Caldwell Dyson has published and presented her work in numerous papers at technical conferences and in scientific journals.
Selected by NASA in June 1998, Caldwell Dyson reported for training in August 1998. Her Astronaut Candidate Training included orientation briefings and tours, numerous scientific and technical briefings, intensive instruction in Shuttle and International Space Station (ISS) systems, physiological training, ground school to prepare for T-38 flight training, as well as learning water and wilderness survival techniques. Completion of this training and evaluation qualified her for flight assignment as a mission specialist.
In 1999, Caldwell Dyson was assigned to the Astronaut Office ISS Operations Branch as a Russian Crusader, participating in the testing and integration of Russian hardware and software products developed for ISS. In 2000, she was assigned prime Crew Support Astronaut for the ISS Expedition 5 crew, serving as their representative on technical and operational issues throughout the training and on-orbit phase of their mission.
During ISS Expeditions 4 through 6, Caldwell Dyson also served as an ISS spacecraft communicator (CAPCOM) inside Mission Control. In 2003, she made a transition to the Astronaut Shuttle Operations Branch and was assigned to flight software verification in the Shuttle Avionics Integration Laboratory (SAIL) and also worked supporting launch and landing operations at Kennedy Space Center, Florida. Caldwell Dyson also served as Lead CAPCOM for Expedition 11.
Caldwell Dyson was assigned to, and later flew on STS-118, Space Shuttle Endeavour, on August 8–21, 2007, which was the 119th space shuttle flight, the 22nd flight to the station, and the 20th flight for Endeavour. Caldwell Dyson was assigned as Mission Specialist #1 on this flight. During the mission Endeavour’s crew successfully added another truss segment, a new gyroscope and external spare parts platform to the International Space Station. A new system that enables docked shuttles to draw electrical power from the station to extend visits to the outpost was activated successfully. A total of four spacewalks (EVAs) were performed by three crew members. Endeavour carried some 5,000 pounds of equipment and supplies to the station and returned to Earth with some 4,000 pounds of hardware and no longer needed equipment. Traveling 5.3 million miles in space, the STS-118 mission was completed in 12 days, 17 hours, 55 minutes and 34 seconds. Finally, during the flight of STS-118, Caldwell Dyson celebrated her 38th birthday in space.
On April 4, 2010, Caldwell Dyson joined the Expedition 23 crew aboard ISS. She lifted off on April 2, 2010 from the Baikonur spaceport aboard a Russian Soyuz capsule (Soyuz TMA-18). After 176 days duty as part of the Expedition 24 crew, she returned to Earth with the Soyuz TMA-18 landing unit. Together with commander Aleksandr Skvortsov and flight engineer Mikhail Korniyenko, Dyson landed in Kazakhstan on September 25, 2010.
In a television interview on the 40th anniversary of the first moon landing, she said she is the first astronaut who was born after Apollo 11.
As Tracy Dyson, she is the host of a series on NASA TV called “StationLife”, which focuses on facets of life aboard the International Space Station.
She appeared on Episode 3 of MasterChef Junior Season 4.
On March 21, 2017, Dyson stood behind President Trump as he signed a bill for NASA to send humans to Mars in 2030s and receive $19.5 billion in 2018 funding. Dyson and fellow NASA astronaut Chris Cassidy presented Trump with an official flight jacket during the ceremony.
You can read about many more inspiring female astronauts who were hams at the following links
https://en.wikipedia.org/wiki/Catherine_Coleman
https://en.wikipedia.org/wiki/Eileen_Collins
https://en.wikipedia.org/wiki/Samantha_Cristoforetti
https://en.wikipedia.org/wiki/Nancy_J._Currie-Gregg
https://www.jsc.nasa.gov/Bios/htmlbios/dunbar.html
https://www.nasa.gov/astronauts/biographies/jeanette-j-epps/biography
https://www.jsc.nasa.gov/Bios/htmlbios/godwin.html
https://www.jsc.nasa.gov/Bios/htmlbios/helms.html
https://en.wikipedia.org/wiki/Yelena_Kondakova
https://www.jsc.nasa.gov/Bios/htmlbios/lawrence.html
https://en.wikipedia.org/wiki/Sandra_Magnus
https://www.jsc.nasa.gov/Bios/htmlbios/metcalf-lindenburger-dm.html
https://en.wikipedia.org/wiki/Barbara_Morgan
https://en.wikipedia.org/wiki/Lisa_Nowak
https://www.nasa.gov/centers/johnson/about/people/orgs/bios/ochoa.html
https://en.wikipedia.org/wiki/Kathleen_Rubins
https://en.wikipedia.org/wiki/Yelena_Serova
http://www.esa.int/About_Us/Welcome_to_ESA/ESA_history/50_years_of_humans_in_space/Dr_Helen_Sharman
https://en.wikipedia.org/wiki/Heidemarie_Stefanyshyn-Piper
https://en.wikipedia.org/wiki/Kathryn_D._Sullivan
https://en.wikipedia.org/wiki/Janice_E._Voss
https://en.wikipedia.org/wiki/Peggy_Whitson
https://en.wikipedia.org/wiki/Sunita_Williams
https://www.nasa.gov/astronauts/biographies/stephanie-d-wilson/
KRK VXT6 Repair
Some time ago I picked up a powered studio monitor for about $20. The music store was closing down and the speaker had a fault- the tweeter wasn’t working. These studio monitors of this size range in price from about $200 to $400, so I couldn’t pass up the deal, as I was sure I could repair it – one day.
That day finally arrived. I had purchased a spare tweeter which had sat in the parcel unopened for some time. When I unpacked it, you guessed it, it was the wrong part. Given that it had come from the US, the return postage added way too much to the cost of repair, so I decided to repair the existing tweeter.
There isn’t much to a permanent magnet tweeter, basically the only electrical component in it is a super-fine winding of copper. This usually fails to due physical stress or sometimes an over-voltage or over-current fault. All that is required is to solder the broken wire- easy right? Well the wire is quite a bit thinner than a human hair and enamelled and wound very tightly into a place that is difficult to get to. You got the picture?
The good story is that after one repair, a subsequent failure and another repair, the speaker works great
Shack of VK2KMI 