MarkFromSales' Build Log - Learning


#1

Hello World,

I’ve been tinkering with electronics since childhood and am looking to learn a bit more detail. My projects generally center around holiday decoration such as Halloween. I’m looking to get into PCB design and prototyping to enhance this hobby!

Ultimately I’d like to share some of my projects in a more polished fashion that can be reproduced reliably :slight_smile:

Thanks,
Mark


#2

Finished Start Here!

Logistics last night and Mindset + Resources this morning before work :slight_smile:


#3

Welcome Mark, there is never a shortage of stuff to learn and do around here :slight_smile:


#4

This is a build log entry for a 10MHz frequency reference

This sort of thing is fairly well documented in other places, but I wanted to use this as a way to learn. Most of my equipment has 10MHz frequency external reference capability and, although I don’t really need it today, I’d like to learn more about the technology in general how it’s used in instruments.

eBay often has 10MHz frequency references as components pulled out of telecom or similar equipment. After some quick searching I found that Rubidium is listed as one of the most stable and common references available. I bought an Efratom Rb 10MHz oscillator and this build log is to track efforts associated with getting it working.

I couldn’t find much direct correlation between the device, its labels, and documentation. The FRS manual and pinouts accurately describe the device and its behavior, so I’m assuming I’ve got this correct so far :slight_smile:

The connector that came with it was a pin type rather than solder cup. The heat from the soldering appeared to have weakened the pins resulting in some breakage on pin 1, causing issues with my testing.

Materials so far

  • Efratom Rubidium Oscillator (eBay)
  • ITT Cannon DAM11W1S connector (Digi-Key IDAM11W1S-ND)
  • ITT Cannon DM53740-5008 coax pin (Digi-Key DM53740-5008PG-ND) - this turned out to be too small for my coax
  • ITT Cannon DM53740-5002 coax pin (Digi-Key IDM53740-5002-ND) - larger diameter on the coax side
  • Amphenol 031-4803-RFX BNC panel adapter (Digi-Key ARF1685-ND)
  • Amphenol 115101-01-06.00 BNC RG-316 cable in 6" length
  • Mean Well IRM-60-24ST 24V 2.5A 60W AC-DC converter (Digi-Key 1866-3068-ND)

Efratom FRS Manual

Efratom FRS Pinouts

My unit’s label

Screenshot of waveform (square, sort of)

After reading through the documentation it looks like pins 1, 4, and 7 are not for customer use and there is some intersting items in the documentation. I connected them to my DAQ and ran a 60-minute capture from power-on to see what happened.

The documentation says that at power on the unit provides 10MHz via a crystal for about 4-minutes until the Rb lamp heats up. After the Rb lamp is heated it’ll switch to Rb instead of crystal. This can be monitored by looking at the “Lock” pin 1 voltage; ~5V (mean is 5.1) is crystal and ~0V is Rb.

Check out the chart below, data captured with U2351A via Benchvue, exported to Excel for charting, annotations done in PowerPoint

It’s very clear on my Siglent SDG 2042X counter function that the crystal is quite accurate and fairly stable, whereas the Rb is dead-on 10MHz and extremely stable.

Power draw is >1250mA while crystal is running and lamp is warming, drops down to 300-400mA after Rb locks. I was using Eevblog’s uCurrent for this with a 3V battery. I’ve since soldered in an external battery connector and will use a 5V source from now on

Next steps:

  • Re-run tests with a 5V source in uCurrent (3V current reading max is 1250mA) or run through DMM
  • Package unit in metal box with appropriate PSU and cooling: Learn high-level thermal design principles
  • Signal quality causes and does it matter? Learn high-level RF stuff and associated details
  • Figure out how to use DAQ as frequency counter and if reliable
  • Discover value of a frequency standard in my lab and projects

#5

Finished the first couple of videos for Shine on. I created my first board and ordered a few along with parts! Learned a lesson here about grabbing the right sized part; accidentally chose a larger LED and couldn’t find any on Digi-key. Ooops! Fixed the part to 1206, updated the nets, updated the pcb, and ordered three of those… now to wait on shipping!

First month has already paid for itself for sure. I’ve been wanting to create a PCB myself for ages but just found it too daunting :smiley:


#6

Awesome, glad to hear you got a board out! You’ll love the feeling of holding it in your hand, I still marvel when something I designed on a screen becomes real in my hand. Plus it all gets easier the more you do it.


#7

Sweet, the boards have arrived and I got them built

Check out how much brighter the 4520 LEDs units are on the goof-up board, wow!

I used a Dremel 7700 with the 240 grit sanding band to clean up the pointy bits on the sides and the corners.

A big thank you to @ChrisGammell and the Shine-on project for getting me my first PCB build! I’m excited to move through this and get some of those projects I’ve had in mind made into reality. Marvel is the right word for sure :smiley:


#8

Congratulations Mark!


#9

Getting to Blinky 4.0 really comes off the rails at “Creating the Layout” – the latest version of KiCad is wildly different in appearance and behavior

I may have to re-install 4.x if I can and start over, or at least figure out how to have it do the translucence :-1:

=== EDIT ===

Issue resolved by virtue of RTFM, they moved this functionality to its own button setup on the left menu bar. This new methology is tons better but I’d like to see one for transparency in addition to the new outline mode


#10

I found in 5, that you can double click the colour icon in against any particular layer and you can change the colour and its opacity.


#11

Oh wow, that’s awesome! If you right-click on the that same block you get layers options as well. This is exactly why I’m here. These programs can be daunting if you’re new to this and learning on your own.

Thank you!