Current Engineering Project

I keep this engineering notebook more for my own use more than for any other reason. It's invaluable when trying to find a solution to a problem I know I've solved before. You are welcome to browse though it to see what it takes to build a SETI station. Questions or Comments? Email me: Seti@SETI.Net

You can access earlier chapters from the main menu (Engineering | Notebook) or use the custom search below. This section changes a lot so refresh your browser and Let Google do the search for you (below):

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Volume 12 Chapter 72

410 Waiting for China 2018-03-19

I finally decided to replace the cheap plastic 16 pin circular connector that brings logic and power into the Head End Electronics with a weather tight connector. Locally, even used, these are $25 or more. From China they are $8. Should be here this week. I have four on order.

409 RJ-45 Pinout for Antenna 2018-03-09

The RJ-45 terminated cables between the RS-232/RS-485 right on up to the Kerr I/O controller in the Head End Electronics are all stright, non-cross over cables. Pin out as shown below:

Header Pin Signal RJ-45 Color
1 Y 1 Brn
2 Z 2 Brn/Wht
3 A 3 Blu
4 B 4 Blu/Wht
5 N/C 5 Orn
6 Gnd 6 Orn/Wht
7 +5 7 Grn
8 Gnd 8 Grn/Wht
9 5
10 Gnd


408 RJ-45 Pinout 2018-03-06

Terminating an RJ-45 cable is not for the faint of heart. You need a special crimping tool, the patience of Job and a table like this one to get the colors stright

RJ-45 Pinout Table. Use the left side colors (T568A)

407 ... and two steps back 2018-03-05

While working on the SETI Pixel amplifier and peak detector to work, I ran into problems with my digital oscilloscope. This is an OWAN 100 MHz mixed signal device that is three or four years old and was a main stay of my workbench. It quit triggering and could not hold the date/time correctly. So I opened it up thinking the stay alive battery needed changing. I removed it and then found that I had to order it on-line from Digi-Key. So I did.

A few days later a box from Digi-Key arrived. It was 1' x1' x 3' This could not be the watch battery I ordered.

It Was...

At least it was well protected.

I still need to install it in my 'Scope.

While I was waiting for the battery to arrive I decided to rework the Head End Electronics to fix an intermittent problem where the filter relay would not reliably close. While I was at it I decided to add some temperature sensors and a voltage sense so that I could monitor what is going on up at the focal point.

Lid side with Kerr I/O Controller Module

Head End Electronics

Of course the RS-485 string of modules no longer works so I have to get that going.

The list goes on and on.

406 SETI Pixel Assembly Chainsaw 2018-02-25

I had most of the first SETI Pixel assembled and then realized that I had installed the Arduino Nano on the wrong pins of the header. I tried to Solder Suck the pins clean but that didn't work. I tried Solder Wick -no luck. Finally I switched to my tried and true method the Chainsaw.

This is to carefully (best you can) cut the bad Nano out of its position, clear all the header pins, align the pins and reinstall a new Nano.

Bad Look

Better Now

Video of it coming to life

The SiPM board is not attached on this but coming together now.

405 Stopping Windows 10 Updates 2018-02-07

Windows updates are thrashing me. When ever one happens I have to reset my system to account for the changes it brought with it. Most of the changes are important and I do want them but I want them when I WANT THEM not when MS decides to send them out.

This is the way to postpone updates under your control.

  1. Open the Run command (Win + R), in it type: gpedit.msc and press enter
  2. Navigate to: Computer Configuration -> Administrative Templates -> Windows Components -> Windows Update
  3. Open this and change the Configure Automatic Updates setting to ‘2 - Notify for download and notify for install’
  4. Open the Settings app (Win + I) and navigate to -> Update and Security -> Windows Updates. Click ‘Check for updates’ which applies the new configuration setting
  5. Restart

404 Lost in Time 2018-01-30

While I am waiting for the orders to come in for the Pixel material decided to take a closer look at my equations of time. I think I have some problems.

I make heavy use of 'Practical Astronomy with your calculator' third edition by Peter Duffett-Smith. This book has easy to understand calculations for all the various formula needed to calculate time for a SETI station. I decided to get the latest version of the book in the hopes that it clears up some confusion that has been giving me fits. I downloaded the latest from Amazon ($30) and it started right up as an eBook - good. This addition of the book is written around Excel spreadsheets unlike that last version which should help clarify some other problems I was having.

Then I attempted to download the spreadsheets. I went through all the usual rain dance with Captcha and submitted it to Cambridge, the publisher. Nothing. Again and again Nothing came back.

I attempted to call Cambridge customer service (don't bother) and finally resubmitted the Captcha with my crummy gMail account rather than my own. This time it worked.

So I will be checking all my time equations against the spreadsheets. Stay tuned.

403 KiCAD Training 2018-01-26

have decided to make KiCAD, which is an open source (and free) schematic capture and board layout system, my basic hardware development tool. To use it I need training - its not falling off a log simple. So I am starting a Udemy class:

Its free so why not.

Why not? - well I'll tell you why not.
After a few hours of working on this course and making adjustments for the fact that the instructor was using a very early version of KiCAD I finally gave up.
Not being a quitter I moved on to the next to free course on KiCAD. We will see how this goes.

As expected the free courses were worth every penny paid for - Don't bother.
I did find a very good course from Udemy the Online school. This class "Tech Explorations KiCad like a Pro" is very will organized, up-to date and useful. If your trying to learn KiCAD for $15 it is hard to beat.

402 SETI Pixel Cosmic Ray Detector 2018-01-16

I have received two SiPM's from sensL ($150) and two pieces of scintillation plastic from (BC-480 5cm X 5cm X 1cm) from iradic via eBay (item 263355405917 $60). This is cut and polished just for the CosmicWatch project.

Most of the other parts needed are on order and will arrive over the next month or so. The PC boards from ELECROW are problematic. The order for two sets went it but I think they have a problem with their web site. I'll have to check back on it.

I decided to hold off on ordering the cases and laser cut front panel because they come from ELECROW as well and because the pixel can be built without them.

I give up on ELECROW. They are having problems with their web site and don't seem to respond to my eMail messages outlining the problems. I have switched to seeed studio which seems to have a better handle on the process.

Order was placed for two pcb's cost was $35 or so with a promise of a quick delivery.