Author Archives: Allen - WD0DXD

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.

Hallicrafters S-38B Restoration – Part 1

Just to show that we like the old as well as the new, we have started a restoration project on a Hallicrafters S-38B.  This particular radio we purchased off of Ebay a year ago.  It is in pretty rough shape, so this should be interesting. Whene we got it, it had shredded newspaper in it for packing.  We didn’t get charged extra for the dead mouse living in the newsprint. (Tip, when storing old radios, don’t fill them with newspaper, great home for rodents and it really holds in the moisture.)

The case has so much rust on it, there is no way way can get away with just a touch up paint job.  So we are going to try a different approach, powder coating.  We found some crinkle powder coating from Eastwood that we are going to use.  If successful we should have a very durable finish that will last for a long time.

The biggest challenge on this one will be the top of the chassis.  It has plenty of rust, so my first thought is, we will have to probably paint it.  I don’t usually like to do that, but I think this one will require it.  We will know more once we get the navel jelly on it.

The speaker looks like it has some tears in it, but it also looks like a good candidate for repair.  Other than that we will recap what needs it and I think I might put an upgraded BFO circuit in it.

So take a look at what we have and follow along as the the fun begins.

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.

Great Drawing Program – Fritzing

In working on some of our projects, it became apparent that I needed to have some form of drawing program to document the interconnections of my components.  I searched the internet and I mostly found schematic programs like KiCAD and PCB layout programs like PCB Express.

While those programs are great, the learning curve on them was more than I wanted to tackle at this point.  I just need something that I could drop some objects on and then draw the interconnect wires for each board.  Then I could take the boards off my breadboard and put them in the chassis and reconnect them.


I also really didn’t want to have to create the Arduino boards from scratch.  Well after a short internet search, I came a crossed fritzing.  So far it has meet all the requirements I had and more.

You can layout your project in breadboard mode and then convert it to a schematic and even produce a template to make your own boards.  They also have a FAB option to have professional PCBs made for you.

You can also share your projects with other users.

The library they have has many of the popular maker boards already in the collection.  They have all the Arduino boards and shields and many popular third party boards.  You can also make your own custom parts.

I just started working with it, so as I go forward I will update my findings.  It is getting easier and easier to build your own project.

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  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.

Pic-A-Star Build Part 1

As part of my new Ham Shack build I am going to put together a new Transceiver.

The Pic-A-Star – Software Transmitter And Receiver was originally designed by Peter Rhodes G3XJP and first published in RADCOM starting in the August 2002 issue.

The design has been updated by several people over the years and is still very modern in it’s operation.

The original design included homebrew PCB boards.  One of Peter’s goals was that the builder do as much of the building themselves to learn as much about the design as possible.

Since then it has become easier to have PCBs designed and produced.  So now they can be found on the internet from time to time.

Peter designed the transceiver in modules so that it would be easy to build and test.  Each module was a separate PCB board.  If you want to build one, you can still download the templates and make your own PCBs.

Glen VK3PE has designed several versions of the Pic-A-Star combo boards.  Instead of an individual board for each module, he has condensed them into 1 or 2 main boards and a board for the LBF and power amps.

I will be using a combo P1 board set that I was able to get from Harold W4ZCB that he had not used.  I want to thank Harold for getting out in the snow in Februray to get them shipped to me.

One of the updates that have been done to the Pic-A-Star is that the original Pic-n-mix controller has been replaced with a more powerful controller.  The new controller is the TrxAVR.  In it’s original incarnation, the Star had only a LCD display.  The new controller adds the ability to use a TFT display.  I will be using a 5” display on this build.

There are 4 Yahoo Groups and a couple of websites that you need to join or visit if you want to build one of these transceivers.

First the Yahoo Groups:

The first is picaproject – This is Peter’s group where he has stored the original RADCOM articles about the project and the other support files needed to build the original design.

The second group is the Picastar-users group – This is the group where you will find current discussions on current and past builds.  You might also find someone who has a set of boards they would like to sell.

The third is homebrew-radios – In this group you will find discussions about the power amps and the TrxAVR projects amoung other homebrew topics.

The final group is the TFTa_Central group – This group supports the color display subsystem for the TrxAVR board.

A must visit website is Glenn’s – Glenn is the designer of the “Combo” Pic-A-Star boards and he keeps all of the documentation there.  He is currently out of boards, but if enough people show interest, maybe we can talk him into making more.

Finally you will want to visit – this site has information on the TrxAVR project and the Encoder8 board.

In the following video, I cover this, plus I show you how I am trying to document the build and the case that I plan to put it in.

The next installment I will show you some of the parts I have sourced so far and we may start load some components on the the first board.

Couple of new Projects–Network Controlled PS and a PicaStar

In an effort to more fully understand the technical aspects of Amateur Radio I have decided to build a complete station more or less on my own.  I won’t be designing all of the components, only some of them.  I do however plan on assembling most of them myself.  I am going to put them in rack mount cases, so I will also be building the rack mount myself.

I have started a couple of the projects and we will be chronicling them here.  First I have started a Network Controlled Power Supply.  We will be using a 40 amp Switching Power Supply that will be monitored with a Arduino and it will have four network controlled ports.

The other project will be a PicaStar DSP transceiver.  More on it later.

So follow along, and I will welcome any suggestions.

Second Week with the Genesis G59

Spent the last week or two working out some of the kinks on the G59.  I had run PSK-31 and JF65 and I was having really great success.  Made close to 100 contacts in a two week period and was getting great reports on my signal.

I had a few nagging problems the biggest being that at the start of transmission and end of transmission, I would get a HIGH SWR alert on the software.  It didn’t seem to be actually be high swr on the meter or on my external meter, so after awhile I just kind of ignored it.

Then I decided it was time to move forward and try and make some SSB contacts.  I ordered a Heil Proset 6 and when it came in, I thought I would be in business.  No such luck.

Every time I would try to transmit, the mux indication would come on and the SWR ALERT would show up and I would have no output.

To make a long story short, I spent the next three days trying to figure out what was going on.  With the help of Bruce and a couple of other people on the Yahoo Group, I finally figured out that I hadn’t completed the jumpers on the mic preamp circuit and since the Heil uses a HC-6 element which is dynamic, I needed to install a 1 uH blocking capacitor.  I built a little adapter with the blocking cap in it and viola, everything works great.

I made several contacts using SSB to Oregon and Nevada.  I received very good audio reports from both.  Really enjoy working with the kit.

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