Tag Archives: Amateur Radio

Pic-A-Star Project Build – Part 3

In episode 3 of our Pic-A-Star Build, we install the components for the RS232 interface and start installing the components for the DSP and CODEC section.

I find that I made a mistake and installed a 10K thermistor instead of a 10K resistor in the audio amp section, so first I remove that and replace it with the correct component.

I have found that I prefer the 0805 component size over the 1206 or 0603 size.  The 1206 is a little big and doesn’t give you as much wiggle room as the 0805 and the 0603 are just a little small for my tastes.  Call it the Goldilocks syndrome or something, but next time I order, I know what I am going to try to spec.

On the Combo P1 boards, in the DSP section there is a capacitor that isn’t marked real well,  it is C199, I point that out in the video.  I also discover that I need to pay attention to the soldering tabs.  When you put the components on, make sure the long part of the tabs are a crossed from each other.  The space is tight, so sometimes the markings are twisted around and if you are not careful, you can mount them in the wrong direction.

The voltage check in the final section checked out correctly, so next step will be to burn the EPROM with gmon.hex and mount it along with the DSP chip and the CODEC chip.  I am waiting for the CODEC chip, since I had to order it from overseas.  So it may be a week or two before we move on.  In the meantime, I will do a video about burning the EPROM.

L/C Meter IIB Build

I just completed a build of a L/C Meter Kit made by Almost All Digital Electronics.  I have included a video of the build to show how easy it was.  Sorry for the length, I tried something new.  I thought I would tape the whole thing and then edit it.  I won’t make that mistake again, it took too long to edit and I still ended up with a long video.

The build was easy as I said and the kit is really high quality.  I plan on using it to test the inductors for the Pic-A-Star project and my son Brad KD0JCP is finishing up a Genesis G59 and then he will be building the matching GPA10 power amp.  We will use it to check those inductors also.

The IIB measures inductors from .001 uHy to 100 mHy and capacitors from .010 pF to 1 uFD.  It does not check polarized caps.  That range covers most needs and it boasts an Accuracy of 1%.

Take a look at Neil Heckt’s page at www.aade.com.  Tell him KB0ASQ sent you.

Pic-A-Star Project Build – Part 2

In Part 2 of our Pic-A-Star build, we assemble the “Buzzer” tool and install the components of the AF audio amp.

Since it is my first real experience with soldering a large amount of SMD parts, I have to take it slow and perfect my soldering skills with these types of components.

After some practice I am able to get both of the tasks completed with only a few diodes and transistors being sacrificed.

The next episode of our project build will cover the RS232 installation and some DSP building.

Power Management Unit Build – Part 5

Part 5 of our Power Management Unit Build will cover the final physical construction and some information on the sketch we did for the Arduino.

I show you how I wired up the front panel LEDs, Buttons and the project board.  I used the following sources from the internet to determine how to wire up the controls and write the sketch:

  1. http://www.arduino.cc/en/Tutorial/Blink?from=Tutorial.BlinkingLED  // Turn the LED on and off.
  2. http://www.arduino.cc/en/Tutorial/Button  // Monitor the momentary push buttons.
  3. http://www.arduino.cc/en/Tutorial/LiquidCrystal // Display information on the LCD.
  4. http://startingelectronics.org/articles/arduino/measuring-voltage-with-arduino/ // Calculate the voltage and convert it to use on the Arduino.
  5. http://openenergymonitor.org/emon/buildingblocks/how-to-build-an-arduino-energy-monitor-measuring-current-only  // Monitor current with a YHDC SCT-013-000 sensor.
  6. http://www.electronicecircuits.com/electronic-circuits/7805-5v-1a-regulated-power-supply-with-overvoltage-protection-circuit // 5v 7805 1A Regulated Circuit.
  7. http://blog.startingelectronics.com/arduino-web-server-tutorial/ // Webserver Tutorial.

I would like to thank those authors for sharing the information.  I took bits and pieces from them to build the project.

In my next post about the project, I will share the Arduino sketch and provide a wiring diagram.

I am going to leave this project as is for now, but at a later date I want to add the ability to use DHCP for the webserver and then be able to set a static IP address.  I also need to add a security/login method to the project.

Power Management Unit Build – Part 4

In part 4 of our Power Management Unit Build, we start to wire things up.  There are essentially two separate sections we have to wire.

First we wire the power to the power supply and then to the relays, fuses and power poles.  I have a fuse that protects the hot side of the power supply and then each port has a 10 amp fuse installed on the hot side to protect the devices attached to the unit.

I show how I don’t trust the crimp connectors, so I remove the plastic insulators from them and crimp, solder and finally use heat shrink tubing to protect the connectors.  I also use WAGO LEVER-NUTS for the first time.  I am really happy with how they work and plan on using them again.

To wire up the connections for the controls and the Arduino, I use jumper wires from Pololu and some of our own connectors from Flatwater Trading Post.

The 5v power supply is also hooked up.  I have a heatsink on the LM9805 since it runs so hot.

At the end of this episode we have the Unit running like it was on the breadboard.  So we have to finish the wiring of the momentary switches, port LED’s and the current indicator circuit.

We will do that in Part 5 of the series.

Hallicrafters S-38B Restoration – Part 2

In part 2 of our Hallicrafters S-38B restoration, we will media blast the cabinet and then prep and powder coat it with Black Winkle powder coat from the Eastwood Company.

We show the steps we take to prep the metal after we have media blasted it and how we apply the powder coating.

The process works pretty good this time, but we do have a few blemishes.  We decide to live with them on this restoration and hope we learn some valuable lessons for the next time we use this process.

I think you will agree that at the end of the process we have made considerable improvements to the case of the radio.

Next episode we will try a new process to us on applying the decals to the front of the case.

Power Management Unit – Build Part 3

Part 3 of our Power Management Unit Build covers mounting the switching power supply, circuit boards, Arduino and cutting some more holes in the back panel.

First I mask off the back panel and measure the holes for the USB port and Ethernet port.  Then I use a Dremel tool to cut the holes out.  It takes a while to cut the holes, so I need to investigate alternate ways to do this.

After that is done, I lay out the components in the chassis and drill the holes for mounting.  I am careful to use screws that don’t protrude too far below the bottom of the chassis so that they don’t catch on any other equipment when I slide the unit into the rack for mounting.

I also use nylon washers on the project boards when mounting them using metal stand offs.  I am hoping to avoid shorting issues by doing this.  I mount the switching power supply using some “L” brackets that I have made with a 3D printer.

In part 4 we will start to wire the components together.

Power Management Unit – Build Part 2

In part two of our Power Management Unit Build we are going to start constructing the front and back panels of the case.

To start I apply painters tape to the front and back panel in a semi successful attempt to prevent marring of the panels.

Then I use product spec sheets and a caliper to layout the component placement on the panels.

Finally I use a drill press, air hack saw and a Dremel tool to cut out and finish the panels.

In working on the panels I learned a couple of things.

1.  I need to be more precise when cutting out holes with the air hack saw.  I spent a lot of time with the Dremel tool making the cutouts larger.

2.  I will probably need to put two layers of painters tape on the panels.  The air hack saw bounced around a lot and marred the panels.

3.  When drilling the holes, I need to stop and remove the shavings as I go along.  In some areas, the shavings scratched the panels as they turned on the drill bit.

I would really appreciate it if anyone has any suggestions on how to do a more professional job on this process.  It looks ok, but I would like to have a cleaner more finished look as I move forward.

In part 3 we will mount some of the boards and install the components in the front and back panels.  I also still need to cut holes in the back panel for the Arduino USB connection and the Ethernet port.

Power Management Unit Build Part 1

This is the part 1 of my Power Management Unit Build.  The purpose of this project is to create a power center for my homebrew Amateur Radio station so that I can control and monitor it directly from the unit or over an IP based network remotely.

I will accomplish this by employing an Arduino micro controller board that we sell at flatwatertradingpost.com.  The components in the PMU are as follows:

A 40 amp switching power supply purchased off the internet.  It features adjustable voltage from 10 – 13.8V, line and load regulation and Hiccup mode (recovers automatically after fault conditions).

I looked at building the power supply myself as I wanted a switching power supply due to is size and weight.  I found some plans on the internet.  The closest was a design by Manfred Mornhinweg XQ2FOD published in QST in the December 1998 issue.  It looked like what I wanted, but you had to wind the transformer yourself, and I didn’t feel that I wanted to tackle that at this time.  This project is modular in it’s design, so if I decide I want to build the power supply myself at a later date, I can then just drop it in place of the current supply.

The next major part of the unit is the Arduino Mega 2560 board.  I will be using it to control the other components in the PMU.  I have written most of the code and will post it as soon as I have finished it.  There is also a Ethernet shield.

Then we will have a 5v power supply to drive the Arduino, 5v relay board and the back light of the LCD.  There will also be a voltage divider to measure the output of the main power supply.

The front panel will consist of an on/off switch, LCD display, 4 momentary switches to turn the ports on and off and 4 leds to indicate the status of the ports.

The back panel will consist of a power cord receptacle, a fuse block and a set of power pole connectors for each port.

In the video I will show the panel parts and the bread board setup that has been completed so far.

In the next edition of this series I will actually cut out the front and back panels to start construction.