Category Archives: Pic-A-Star

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.

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.