Category: Electronics

Dutch Apple, Please

2021-04-02
Electronicsraspi
0 Comment

Let’s start by recapping my experience with the models and operating systems to frame the discussion.  I’ve actually dealt the majority of the models, and my opinion is much the same on all of them.

Version Comments Operating Systems
2B+ I experienced stability issues and burned up two usb wireless cards.  I worked with the Pidora OS primarily, but eventually gave up and switched to Raspbian.  This did not make it any better as I can remember. Pidora & Raspbian
3A/B The only one I actually “like.”  Excellent for RetroPie and Octopi.  I haven’t used the Raspbian base OS. Retropie, Octoprint
4B I really hate the Pi 4.  Its not much of an specifications improvement over the 3B as far as I can tell.  I haven’t worked with mine enough to know though.  However,  I’ve already corrupted (and destroyed) one SD are a result of the power supply issues present in every single iteration of Raspberry Pi.  That leads to my main complaint about the Pi 4.  Why implement USB-C but not have it negotiate to any of the higher voltage options? Retropie
Zero W Its okay.  The SD cards seems to get corrupted often but they aren’t often destroyed.  Overclocking seems to work different on every single board I’ve bought.  Also, my first ZeroW would segfault when I tried to use the wireless connection. Retropie, Pi-KVM, PiStar
Zero W<2/td>

A very welcome update to my Retroflag GPi. Sadly, since its a new system I set up and clean install and by then I was done playing with. I will say though, I wish I had bought 2 of them. It seems stable enough, and I need to take the time to play with it more.

 

My main beef with the Pi family is that needing a 5.1 volt USB power supply defeats the purpose of using USB to power them.  Add in the awful time I had with the 2B (and the Alfa Alfa AWUS036H that it ate) I’m not really thrilled with them  I’m sure someone will say that by using a properly rated power supply all my problems could be solved.  However, I would argue that if you need a “special” voltage spec, then use a 9VDC or 7.5VDC barrel jack and step down the voltage on the board.

What prompted my post about this an article posted on Hackaday about modify the pi to try to help with the voltage warnings.  My opinion is this: Pi’s are not USB devices.  A wide variety are arguments were made in the article’s comments.  They’re enlightening, but ultimately I think you know the ones that I agree with this.  The Pi5 should feature a barrel jack instead of a USB.  There are a bunch of ways to try to help with the problem but at the end of the day if you put a USB connector in people will use whatever USB they have handy.  The legrand USB outlet I installed at my desk provides 4.87 volts which is with the USB power specification.  It can power a pi zero, and usually a 3B.  However it will completely kill an SD card on the Pi 4.  Even the USB-C charger (that will auto negotiate to 9VDC or 12VDC) cannot power my Pi4.

I loved my 3B retropie setup and in general I’ve been satisfied with the Pi3 devices I’ve deployed.  Using octoprint has been fantastic – I can now monitor my 3d printers remotely from work.  But I’m not sold on the other models.  Here are a few other tips for a less frustrating Raspberry Pi experience.

  • Don’t back up your home directory or configuration files.  Create a complete image the card using dd or follow HowToGeek’s instructions (I don’t run windows in that capacity).  If the SD card dies you flash a new one and go.
  • Don’t use a Pi’s when what you mean to use is a microcontroller.  Arduino, teensy, atiny85 are all more stable (and less money).
  • Don’t use pi’s when you could run a virtual machine instead.  You may even find it useful to spin up a copy of Fedora or Ubuntu server on an old machine.
  • Don’t use them for “mission critical” tasks.  Setup a “hot swap spare”.  $35 for the pi & imaging an SD card over is nothing.

Long and short, if I need to deploy a pie make mine a dutch apple.  By that I mean be cognizant of the limitations and strange requirements of the system and don’t try to get outside of them.  If I use a pi I know exactly what I want and why.

Update 20220417: Comment on the ZeroW2

A Useful Gadget

2020-05-26
Electronicsprogramming
0 Comment

The problem though with developing on an arduino is there’s not a real good way to debug it, other then lots of printing to the serial port.  So, not a “problem” – unless you can’t get a computer near what you’re working or you want to air gap your very expensive laptop from the arduino.  How to solve this?

JeeLabs has developed firmware for the esp-12s to turn it into a wifi serial platform.  I think its out of active development at this point, but it still works – and pretty well at this point.  So, I built a breakout to the esp-link.  And feature creep occured.

This isn’t something I really want to sell or build or what have you.  But I decided today while I was debugging the “LazyVac 31” with this that I would share it for everyone, for free.  Because I can – and because I think its that useful.  Since this post is for the developer amongst my readers I won’t deep dive to much.  Instead, I’ll link the relevant components and share the schematics, stl, and some pictures of the finished project.  If you need more details, feel free to ask in the comments.

The Finished Project. Yes, Full Rebel XS + Macro Lense Resolution

Cura View of the Carrier

Top View of the Board

Bottom Side of the Board

Schematic Diagram

Carrier STL

Additional Notes

  • The USB A on board is for power only.  I have a breakout board that plugs into a USB power supply so it makes sense to be able to power the breadboard.
  • From what I can tell, the esp12-s is meant to run on 3.3VDC.  So, since I had to include a 3.3VD rail it makes sense include a screw terminal for 3.3VDC powering.
  • I added the silicone wire and clips after I built the schematic.  I found out that being able to hook up the two wires with the test clips made my life super easy.
  • I generally use my phone to connect to the esp-12s’ wireless access point and then connect to the serial terminal via JuiceSSH.
  • The extra holes on the top of the carrier are meant to have 12mm magnets pressed in for retaining a cover but I’ve never needed the cover enough to design one.

Components

Flashing the Firmware

This is the command I used to flash the firmware via my frog pin programmer.  You’ll need to download the esptool package for your platform to flash the firmware.  Its much easier then tying to get the Arduino IDE to flash the firmware via the programmer.

esptool-2.8/esptool.py --port /dev/ttyUSB0 --baud 460800 write_flash -fs 4m -ff 40m 0x00000 esp-link-v3.0.14-g963ffbb/boot_v1.6.bin 0x1000 esp-link-v3.0.14-g963ffbb/user1.bin 0x7C000 esp-link-v3.0.14-g963ffbb/esp_init_data_default.bin 0x7E000 esp-link-v3.0.14-g963ffbb/blank.bin

esp-link Firmware

An Update. Not too notable.

2020-04-26
amateur radioElectronicsfedora linuxprogrammingUncategorizedWifi Pineapple
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Hrm, what to update on?  My last post was released roughly 4 months ago.  Who could have imagined where we would be today?  Corona is … mostly a ploy to destroy the economy in the wake of the November elections.  There are some real medical issues that could be present but its to the same group of people who are vulnerable to the seasonal flu.  Its time to get back to work America.

Having addressed that … what else is there to talk about?  Let me rummage about here.  This is more of a scrap bin update so … things might be rough in places.

Projects

The biggest change is that I have a new shop.  I would love to post pictures but operational security and all.  The new shop gives me better capabilities.  I’ve also expanded what tools I have on site.  A basic stick/tig welder, lathe, and work bench are all welcome additions to my capabilities.  I’m looking forward to starting my own business and maybe escaping from the nonsense that is corporate America.  My sales site is already listed on here, but for kicks, check out my offerings at underthebedstudio.com.

I also built a painting cabinet that helps keep the fumes down in the house and give excellent finishes to parts I need to paint.  One of the first projects that I used it for was a drive over antenna base.  My intention to use this at the remaining service events this year that don’t get cancelled as a result of the Panicdemic.

Another cool project I worked on was a Cigar Punch.  With my 3d printer I was able to iterate through designs pretty quickly.  I threw out the iterations but took a picture first:

Only took me 6 tries to get to the form factor I was happy with.  I also finally found a pre-hardened material to make the punch itself from (drill bushings), which was the cause of Mk4 & Mk 4.1.

While I was looking at a few things, I ended up buying an ESP-12s which I found prebuilt firmware that would let me use it as a serial port over wifi.  Pretty sweet.  So here’s my interpretation of it:

Here’s the Schematic for the protoboard above. It uses an 18650 cell under the board for powering everything. And here is the STL for the carrier. I used standard 8-32 screws to hold the protoboard down.  The charger circuit chip is here on Amazon.

Computer Jazz Hands

A few computer things that I’d like to talk about.

First up is the Retroflag GPi.  This is a pretty slick little box that takes a Raspberry Pi Zero (Wireless if that’s your thing) and turns it into a self contained Retropie gaming machine.  Being that its a Pi Zero, it struggles with anything over Super Nintendo but works pretty well for lots of other things.  If you’re into gaming I highly recommend it.  I just wish every single pi unit with the exception of the Pi3 wasn’t so damn finicky.  I do have scripts that allow me to turn off the wifi and the bluetooth and also rsync over wireless.  Code at the bottom.  One thing I would recommend to everyone – just get a bluetooth keyboard at the same time.  Normally I would recommend a 2.4ghz USB keyboard (I’m a fan of this one) but with the Pi Zero and the GPi case – bluetooth is best. I ended up with this one.

Ah, the Hak5 Jasager.  They released the firmware 2.4 for the Mark V a month or so ago.  I hate to say it, but I’ve never really gotten the thing to work as well as I would like.  I’m always fighting with it, and it seems to be always corrupting sd cards – which kills my plugins.  At this point, I would be hard pressed to buy the Mark VI.  Hak5, thanks for all you’ve taught me.  Best of wishes.

What about a Pwnagotchi?  A wifi auth key hacking tomagotchi?  Sweet.  But my dislike of RasPi’s still applies.  Also, its 2020 and now that I ponder the idea – I only see a couple of wifi configurations in the “wild.”  The first is with a proper WPA2 password which can be tricky to catch and crack.  The other is a captive portals with open associations.  And no, fortune 500 employers and authentication portal doesn’t secure the traffic of the users.  With open associations, no reason to associate.  Just grab it from the air.

I built myself a FreeNAS box last year as well.  This makes it super easy to back up my laptop across the network.  A few recommendations

  • Wire your network.  Seriously.  The speeds of a wired 10/100 easily exceed the speeds of wireless.  While you’re at it, this is an excellent time to learn how to make your own network cables.  Pick up a 100′ Cat5e cable and a crimpers + ends and go to town.  Custom length cables make management much easier.
  • Put in a “dumb” gigabit switch between your main computer and the freeNAS.  I bought this one, but I couldn’t tell you if it would better then any other.  Going to gigbit?  Amazing.  Most files get transferred before a status window can open.  And backups – ironically 10 times faster.
  • RAID.  RAID all the things!
  • And, do yourself a favor.  Get a cheap UPS to put the freeNAS on so minor (or major) power outages let it fail gracefully.
  • Having a well spec’d FreeNAS box lets you run servers all the time.  I have one that starts up to handle my DNS requests.  I’m running the Pi-Hole distribution because I’m not a fan of ads.  Or the tracking nonsense that they do.

Getting a FreeNAS box set up was awesome.  I highly recommend it.  Right now, I’m loving everything about it.

I’m still running Fedora 30 on my laptop.  I’ve never really booted to the Windows 10 installation that came with it – just to shrink the partition and I’m considering getting rid of it when I update to Fedora 32.  I’ve held out against Fedora 31 long enough that I think I’m going to wait for 32 now.  I usually do a fresh install.  To many things can get muddled when doing an update and a fresh start it always nice. Probably make an image of the HD again before I wipe Windows 10 though.  Shout out to Clonezilla.  Thanks guys!

Miscellaneous Topics

Affiliate Links.  There’s still no affiliate links here on the blog, and there will probably never, ever be unless the players change their tune.  As I figured, they’ve started to weaponize the Terms of Service and its just not worth it for the little money.  If the Youtube Adpocolypse can hit somebody like Demolition Ranch …. it will happen to anyone.  Free Speech is important – don’t let yourself get caught in the trap.  By the way, COVID-19 is totally Commie China’s fault.

Social Distancing.  Ugh.  Seriously?  Why did it take this for people to realize that door knobs, pin pads, and people are nasty?  They’re just nasty.  And, stay the hell out of my face.  COVID or not, I don’t want you within reach.  Just back off.  If you’re close enough that I could reach out and kick you … maybe you should back up just a touch.

Drones.  I would love to get a TinyWhoop with FPV.  I think it could be super useful and handy.  But then I look at my other drones that I never touch and convince myself its to much.  Drone guys, keep it up.  I’ll have to live vicariously through your youtube videos.

Macro Lens.  Why did I not buy one of these before?  They are super awesome.  I’ve messed with macro tubes, but they don’t work as well as a macro lense does.  I highly recommend buying refurbished lenses and flashes directly from Canon.  They’re a little more (like … $20) then what you would find for used prices, come with a warranty, and free shipping.  I’ve always been super happy with Canon equipment and their repair shop.  Seriously though, is this not gorgeous?  Having a macro lense is great for documenting any of the fiddly things I do, like below.  And honestly, I can see it being “one lense to rule them all” for me.  The kit lens is a close second.

I recently went through an purged my youtube subscriptions.  I think I got rid of half of them – many had been deleted or I no longer watched them.  A few channels to shout out:

  • Andrew Klavan – I love his satirical intros.
  • Marling Baits – He makes fishing baits, and good videos just to have playing.
  • This Old Tony – Dad Jokes and Machining.
  • AVE – irreverant as f*ck.
  • Ivan Miranda – massive scale 3d printing projects.
  • Project Binky – in Colour! Dry british humor, and the only car show I’ve ever liked.
  • Townsends – this man would have killed it on PBS when I was a kid.

The DS213 o-scope.  Not a bad little device.  Short on features, but for the price tag not a bad deal either.  It let me see some things I couldn’t see with my multimeter.  I have a proper oscope I need to repair, but to be honest I’m scared of the high voltage that’s inside.  I found a drybox case online that holds this and the probes perfectly.  Standard USB charging nonsense.

While I’m at it, check on the NanoVNA.  I’ve only really used it for checking SWR but there’s apparently a ton more that it can do.  Here’s my kit, with the adapters I’ll need to get it to work with my equipment.  As big as my go box and antenna setup is, its nice to know I can through this in my messenger bag or goruck with my laptop and be able to make some quick checks.  This does standard usb charging as well but it wants a USB-C cable but doesn’t implement the fast charging spec.  A waste.

Other Life Stuff

Still need to get digital working in my go box.  Hopefully taking the time this week to put my HF rig on a dummy load and do the experimenting that I need to do.

I could really use a vacation.  Somewhere tropical, sunny, and hot would be nice.  Maybe via a cruise ship?  Prices went through the floor now …..

Mentioning drones and how its not really something, I’d really love a Yaesu FT-818.  Oh well, I probably wouldn’t use that either.

In Closing

Rock on folks.  I’m going to peace out for a bit.  Hope you enjoyed the randomness presented above.

RetroPie Scripts

Make a folder in the RetroPie roms directory called “bash” – mkdir -r ~/RetroPie/roms/bash

Copy over bash scripts. I have scripts for enabling and disabling the wifi adaptor, as well as using rsync across my LAN for rom directory syncing

Copy bash-mod/configs/bash into /opt/retropie/configs/

Copy over bash-mod/theme/bash into /etc/emulationstation/themes/carbon (or whatever theme you’re running is)

sudo /etc/emulationstation/es_systems.cfg and add the following code to the <systemlist> tree:

						<system>
							<name>bash</name>
							<fullname>Bash Shell</fullname>
							<path>/home/pi/RetroPie/roms/bash</path>
							<extension>.sh .SH</extension>
							<command>/opt/retropie/supplementary/runcommand/runcommand.sh 0 _SYS_ bash %ROM%</command>
							<platform>bash</platform>
							<theme>bash</theme>
						</system>

Restart Emulation Station

bluetoothdown.sh

#!/bin/bash

sudo rfkill block bluetooth

bluetooth-up.sh

#!/bin/bash

sudo rfkill unblock bluetooth

wifi-down.sh

#!/bin/bash

#sudo ifconfig wlan0 down
sudo rfkill block wifi

wifi-up.sh

#!/bin/bash

#sudo ifconfig wlan0 up
sudo rfkill unblock wifi

Yet Another (Clever) End Fed: AKA The Slinky Antenna

2019-10-01
amateur radioElectronicsgo box
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My first antenna was a simple wire dipole that I carefully measured and built as a linked dipole system so I could work multiple bands (remember that an antenna at resonance both transmits and receives energy better then one “matched” with a tuner). My first solo field day, I found out how well dipoles work when tuning to a different band (they don’t) and how troublesome it could be to mess with an erected antenna (I improvised a mast, and then had to improvise get the legs of the dipole out).

The next antenna I built was based on the W4KGH end fed antenna.  Measure and cut wire, wound my first unun and then off I went with my go kit (a Yaesu 857d and MFJ-929 tuner with a cheap computer PSU to power the rig up) up to a friend’s cabin in Wisconsin. Hoisting this antenna was much easier as I only need one friendly tree and ended up with a basically a sloper antenna.  I was able to cross bands easily and heard a few people working the Colorado QSO Party over that Labor Day and tuned in a Number Station as well.

The end fed antenna was employed again at my Ham Club’s 2018 Field Day where I realized that the noise I thought was from my location in Wisconsin was likely from the power supply I was using. I also struggled to get it to tune on the lower bands. Hoisting was troublesome and while I had a friendly “tree,” I was barely able to get set up.

I’m a member of a Ham Radio Go Kits on Facebook, where a member posted of a slinky end fed on the group.  Using a slinky as a radiating element isn’t really new.  When I first started my journey as a ham, I ran across the Slinky Dipole and there was mention of the slinky endfed.  What appeals to me the most about the design is the “mast” that supports it.   A simple 20′ shore pole in the center of the coils of the slinky is all it takes

Credit where due

Due to the fact that I live in a HOA (the bane of hams) I can’t hoist an antenna permanently.  There’s also a dearth of the required “friendly trees” in the area.  I can get this antenna set up in under 10 minutes.  Tear down is 10 minutes as well.  This means I can spend more time operating then putting nonsense up in a tree.

This picture was taken before I had completed the mounting horn for the match box.  Before I talk about the design exhaustively, let’s talk real quick about how well the antenna does as far as SWR is concerned.  Ironically enough, the only portion of the band that this doesn’t need a tuner is for 2 meters!  Below is a table of 4 SWR sweeps of the antenna.  I swept the entire spectrum with a single single with and without a counterpoise and a double slinky (two slinkys I soldered together) again with and without a counterpoise.  Generally a single slinky without a counterpoise is the winner, except for a few flukes.  Overall, for field deployment I’ll bring a single slinky and the counterpoise but not bother to put it on.  For 40m and up, this generally presents less then 7:1 SWR.  If 80m is my goal, I’ll put the double slinky on and go.

Unlike my last two projects with picture ad nauseum, I’ve picked a small subset for your viewing pleasure. Here’s the CAD profile of the legs for the stand.  These were cut with a water jet from 14 gauge stainless steel.  The circles within the leg are to reduce the overall weight of the leg.  The notch at the base of the leg allows me to easily stake each of the feet.  Some would argue that its to heavy for the application, but the extra weight helps keep the antenna from tipping over without the stakes.  I think its a good balance.

The clamps that hold the legs to the shore pole are 3d printed – as are many other things within my ham radio world.  There’s some 3m double stick tape to keep them in place.

I designed the legs to pivot about the middle clamp so the top hole is drilled to provide clearance for the 8-32 bolt and lock nut that keep them in place.  The top and bottom clamp keep the legs in place.  For these clamps, the legs are tapped instead.  The leg flips to either the deployed position or stowed and an 8-32 bolt is threaded through.  This means that I don’t have to muck with a small fiddly nut in the field.Shot of the “clamps” being printed on my monoprice.   A few shots of the slinky.  One showing how the caps are attached to the slinky, and then a full profile of the single slinky and the double slinky.  I made small retaining straps using elastic and large buttons.  The wire coming out of the bottom is to connect the slinky to the match box.  I did the same sort of arrangement on both stacks of slinkies. Honestly, you don’t need to make it this complicated (in the video up top a simple lanyard clip is used but I always over complicated things. The matchbox.  The banana jacks ordered were to long and were almost touching each other.  I 3d printed some stand offs to try to clean this up.A shot of the mounting horn on the match box.
Found a neat spool on Thingiverse for the counterpoise wire (which per the above table isn’t generally needed).  Printed at 50% x & y, 75% z.

Cloning the Fluke T-Pak

2018-10-05
ElectronicsUncategorized
0 Comment

I own a Fluke 87V meter. It has more buttons and features then you could ever hope to shake a stick at. It’s probably an overpowered choice for what projects I’ve done but since I never quite know what I’m going to end up working on, I feel its better to be over rather then under prepared. I bought it because of my dad’s Fluke 83. He’s had that for longer then I’ve been alive and I wanted a one and done meter as well.

One of Fluke’s accessories for their meter line is the Fluke T-Pak, which allows you to hang the meter from any metal surface, by means of magnets.

I was browsing thingiverse, and came upon a clone I could 3d print.

So, I commenced to print the insert. Once I had printed the insert I needed something for the magnets to press in to. I had to try a few different magnets to get the size that I needed, but finally settled on these magnets from grainger. I did have to epoxy & press them into the insert.

The end result is that for about $10 of materials I had successfuly cloned the fluke t-pak. With fluke charging about $45 for theirs, well I definitely had enough left over for a cup of coffee at Starbucks to write this post. What a day to live in. 3d printing is revolutionizing our world, whether we like it or not.

And in action:

Download the Base STL for free. Viva la Revolucion!

Shack-In-A-Box: Initial Build

2018-09-07
amateur radioElectronicsgo box
3 Comments

What’s the point?

Go boxes exist across for a spectrum of purposes. Perhaps you have a sewing box, or a toolbox, or a box with everything required for D&D. By doing this, you have everything needed for that particular task and can be ready to go within a few moments notice – or not have to get everything collected for Friday’s game and you’re already late. Building a ham radio go box is no different – you can grab the unit, head out the door and and once on site have everything you need to operate.

I am primarily a portable operator (as a result of my HOA) who must set up each and every time. With a go box, having all my radios are mounted in a single portable box with the radio gear and power connections set up means I will have much longer to operate – and that much more isn’t left to chance.

I was inspired to build my go-box after joining the Ham Radio Go Box group on facebook. I ended up throwing my new 2m mobile in there as well as a result of starting to run my club’s monday night net. Here are pictures and remarks of the process.

What’s in the Box

Check out the for pictures. In the go-box, I have

  • HF + 2M/440 by the Yaesu 857d
  • MFJ 929 HF tuner connected to the Yaesu
  • 2m/440 + Crossbanding from the Alinco DR-735t
  • Built in illumination for dusk or after operations
  • Built in cooling for both radios
  • Onboard 120V power conversion and a power monitoring system for amp load and voltage (voltage is monitored on battery power)
  • USB Phone charging

Build Log

I drew an initial layout in cad to determine if I should purchase a 4u or 6u rackmount case. The rackmount system comes from the portable audio world and specifies a certain amount of space and a mounting system. Trying different variations, it was decided that a 6u box would provide for all the equipment I had currently, and some future expansion. I decided that purchasing a commercial rackmount would give me better results then building my own box as I have seen some do.

Ultimately, I selected the SKB 6U Roto Shallow Rack unit over a comparable Gator Box (or eurolite) for two reasons. The first was that the SKB features an internal gasket that while it won’t make the water proof, will certainly help keep out the spirit dampening rain storm. The second was that the SKB was better reviewed then any other rack mounts I had found. The additional sturdiness of the unit was worth the additional expense. I avoided the particle board solutions by Eurolite & Musician’s Friend due to the weight. Both the wood and plastic boxes are flight rated so there should be negligible difference in their durability with the weight of the poly boxes being at least half the weight of their wood equivalent. Radios & other things will make the box heavy enough on their own. Then, I needed to go from the vertical pillars of the rackmount system to a horizontal surface to mount the radios, tuner, and other gear. To rack them into the go-box, I ordered 1u racks from Navepoint. By ordering directly from Navepoint I saved about $2 each rack, exchanged an email for another $5 off, and still had free shipping. Much cheaper then purchasing from Amazon


I used the mounting brackets provided by yaesu and alinco for their radios. No reason to reinvent the wheel for a custom solution when what was provided works well. The radios were mounted in the slots in the navepoint shelves with the brackets that came with the radios from their manufacturers. You’ll note that at times the radio shelf is clamped a small masterforce vise. This method of keeping the shelf vertical to work on it works fairly well, especially when you let gravity work to your advantage. This is my go to method for handling the shelf when it is outside of the box.





A Blue Sea Systems 6 Circuit With Coverwas sourced from amazon. This helps protect the radios from short circuits with fusing, as well as providing a neat and clean way of distrubuting the power from whatever source I am using. I should note that its built with metric standards. Because of this, i found it a bit difficult to work with as I have minimal metric tooling. An initial fitting was done to make sure I was on course with the space requirements of everything so far. (I apologize for the potato phone pictures.)



Because of my desire to run the system from a battery, I ordered DC Shunt Monitoring System from amazon. I chose this particular model as opposed to the some of the meters around for its low draw – and that I can shut of the monitor and have no draw at all. The system displays the current voltage of power system, amps in use, watts, and watt hours. I needed a way to encapsulate the shunt, so I designed and 3d printed a shunt box that would allow me to mount the shunt in any orientation. The bottom of the shunt box has two hex hole for a 6-32 nuts to press in. The top has holes for 6-32 fasteners to fit through and tighten via the 6-32 nuts. The center hole is to bolt the shunt mount on the frame with a 1/4-20 bolt. STL below. There are tunnels for the main power wires and the display relay wires.





To mount the monitoring display, the power switches, and a USB charging port, I needed a small panel about the size of a 2u panel (3 1/2″ x 19″). The layout of the switches, power display, USB Charger, and control switches was mostly laid out on the fly. After layout, cutting, and test fits the board was sanded through to 400 grit and stained. Rustoleum Spray Lacquer was used as a protective coating. I found that laying the piece out horizontally and using heavy coats resulted in the best surface finish.

Each function of the box (such as the radios, the usb charging ports, the monitoring display) can be switched on individually. I sourced a number of 13.8 VDC 25A switches from Digikey instead of using lower amperage switches and relays – again with battery powered operation in mind. Because the switches were designed to be mounted in thin plastic, not plywood, I needed a way to engage the locking tabs on the switches on the board. Switch mounts were designed and 3d printed to engage the locking tabs on the switches and screw into the face of the board. The monitoring display was also made to be mounted in thin plastic or steel, so a frame for that was also designed and 3d-printed.




To keep the wiring neat and tidy as I run it to the switches, power supply, and more small wire mounts were designed and printed with my monoprice. An 8-32 nut is pressed into the slot, a #10 fender washer is placed in the top, and then it is bolted onto the tray with a 8-32 x 7/16″ machine screw for wires to run through. This helps keep the wiring tidy and supported.



Adding a feature I probably don’t need, stick-on LED tape was installed around front of the box. First the surface is prepped with isopropyl alcohol and then allowed to dry. The LED tape is applied, leaving the power leads in a supposedly convenient position. Deans Connectors were ordered to allow me to connect the switching panel to the LED tape. With these connectors installed, it becomes trivial to disconnect the lights from the switch board. High quality adhesive shrink tube was applied over the solder joints to protect against shorts.

After this, I began the final fit up and cable management of the wiring inside the case. This was fussy, test, trim, retest, retrim, crimp, retrim, install, remove work that consumed the better part of four days of work. Cable management is an important part of any job and I didn’t want wires hanging in loose bundles looking like garbage – hence printing and installing the wire mounts. Here you can just see the power feeds for the radio fitted over the top of the shelf. They are then fed down through the slots in the trays to each radio. Later, I realized that I needed to open up the slots as an powerpole can’t be pulled back through. Two of the ventilation slots were cut to form a generous slot to pass the powerpoles through. These were cut with a dremel, and then some hand filing to clean up the holes. I also needed to remove a section of the top rack on the side so that wires could pass out from behind the distribution box and make the required connections. Again, this was cut with a dremel and then hand filed.





I had to decide how to hook up the radios – whether I was going to use the factory connectors or powerpoles. I ended up with a mix of the two. I removed the alinco connector and switch the radio directly to Anderson Powerpoles. For my 857, I decided to keep the yaesu connector because of the brown wire (a stupid item imho but best to leave it). Powerpoles were installed on the drops, then a generous coating of dielectric grease was applied. I’ve read that powerpoles corrode quickly so this will help keep them from oxidizing without damaging the ability of power to flow across the tabs.


Axial fans were ordered to provide additional cooling to the radios. The fans from digikey were selected to to provide maximum airflow with a low 38.5dBA noise. If needed, I can mount a rheostat to slow the fans and lower the noise, at the cost of airflow. A fan mount was drawn in cad, and a shop favor called in for the panel to be cut with a water jet. Once it came back from the shop, a coat of rustoleum professional grade primer and then rustoleum gloss black was applied. I refuse to utilize krylon paints in my shop. I broke a fan blade just by tapping with with my finger, so I clearly needed to provide some protection to the fan blades. A fan cover mirroring the style of the grid on the fan mount was designed and printed. I reasoned that the fans could push no more air then they could pull, and mirrored the design of the fan mount. To save print time in the future, I redesigned the guards to have a sleeve and cover. While the sleeve adds slight complexity to the walls and increases their print time, it will save roughly 3 hours should I need to redesign or reprint from breakage the guard grid in the future. Here are the sleeves, and the first & second iteration of the guard. Printing with just shoulders pressing against the fan saves an hour of print time on the monoprice.

Small rubber grommets were ordered and 3/32 holes appropriate for the grommets were drilled. Grommets installed, the wires were passed through the side of the guard, and then wired in parallel to a deans connecter which was then hooked to the appropriate circuit. As will the led lighting, this makes it easier to service various parts of the box. The fans are attached with 6-32 bolts and acorn nuts for a finished look. The fans pull air from the rear of the case and push it towards the front. The user of the go-box experiences a slight breeze.











A “rack” of sorts was designed and printed for the MFJ-929 HF Tuner paired with my Yaesu 857d. This rack barely fit on my monoprice – I had to set the bed size to 121mm x 121mm and get rid of the brim to print these. Taking advantage of rapid iteration through 3d printing, here is the mark 2 version of the tuner mount mount, which loses a mounting hole on the base, and eliminated the need to drill and tap the side of my tuner as I had originally planned. A slot that fits to the center screw on the side of the tuner helps center & retain the tuner in these mounts. Then, a sliding armature was designed that will insure the vertical retention of the tuner.

With the initially printed arms, I had issues with the print warping, and the arms tilting back. I lost some faith in the retention ability of the arms because of this. I initially planned on printing the arms in a way that they couldn’t warp from heat differences as the layers were applied. I changed from the initial arm design to Mk 2.5 to help reduce the print time, and to make things look nicer. After a test print with the arm at about 15° on the print bed I decided I didn’t like the results when I cleaned up the print. So instead, I printed two more arms, gently heated the pla prints, then pressed down with a wood slat to intentionally warp the print so that when bolted onto the mounts, they would squeeze down and against the print. Mk 1 & Mk 2 below.

The fan panel makes it harder to get to the pl-259 jacks on the back of the radios. To make it easier, I ordered and installed some right angle adapters to the radios. The 857 was connected to the tuner with a cable that has a right angle connector.














Closing Thoughts

At this point, I’m posting the build log. I will have to make a few updates for things such as integral power supply, hand mic mounts, and the smaller 2M antenna I’m building to keep in the go-box for deployments. However, the go-box itself is practically done.

 

There are a few things I will do differently for the next build. I would have a smaller switching section. The parasitic draw of the radios is not enough to justify the cost & trouble. If I was doing a SOTA where I had to hill climb for this, I would take a Yaesu FT-817nd or Yaesu FT-818. Still, for this box I think it all works well and I am in no hurry to tear everything apart to make Mark 2. Even though this is less of a go-box and more of a shack in a box I’m satisfied with the result.

Gallery

Go Box at Field Day

The go-box’s first deployment was the ARRL’s 2018 Field Day. Note that the tuner is retained by string and that the power supply is external. I simply ran out of time to get everything done.

Operated with my W4KGH End Fed Antenna (Doc 1, Doc 2) with 9:1 Unun, 55’ radiator & counterpoise. Worked well on 40M. 80M was barely able to tune. The noise floor for 80M was S5-S9 though so I was unable to hear anyone.






Random At The Bench

I had an issue with the amperage display reading incorrectly. Here I am verify the wire and testing its reading against my fluke 87V.


Parts

Ordered Parts

  1. SKB 6u Shallow Rack
  2. Blue Sea Systems ST Blade Fuse Block
  3. NavePoint 1U Racks
  4. Switches
  5. PowerSupply
  6. DC Shunt Monitor
  7. 12V Warm White LED Strip Lights
  8. 18 Gauge Stranded Hookup Wire, White
  9. 18 Gauge Stranded Hookup Wire, Black
  10. Deans Connectors
  11. Shrink Tubings
  12. Case Fans
  13. 90° PL-259 to straight PL-259 cable
  14. 90° UHF adapters
  15. Rubber Grommets

Printed Parts

Note: I have chosen to provide many of the solid model STLs for the 3D Printed Parts I used. 3D Printing is an incredible technology, and I amazed to be able to use it so easily. However, I provide these STLs without support. I may have suggestions or warnings but they are provided as is. I hope that they are useful to you, but they may not be.

  1. Switch Plates
  2. Wire Guides. Note – max capacity is 4 12 gauge automotive wires. A 8-32 x 7/16″ bolt will rack these perfectly with no interference to the wires with a .050″ fender washer and a 14 gauge steel shelf.
  3. DC Shunt Box STL’s
  4. Fan Sleeve
  5. Fan Cover
  6. Tuner Mounting Fixtures

Creative Commons License
These STL’s are licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License. I do not certify anything other then loosing your beer money over these. They may or may not be useful. Remember, only Hu can Prevent Florist Friars!

Building a Ham Radio Power Supply

2016-10-12
amateur radioElectronics
4 Comments

Ham Radio Isn’t Cheap

Much like shooting, ham radio is expensive. I think all fun hobbies are. But after spending $820 for the radio, I wasn’t in the mood (or the financial state) to drop another $100 to $150 on an Alinco Power Supply. Slick as spit, but not worth it.

So, here is what I came up with:

My power supply has the following features:

  • Hacker cred. I put it together, and it looks nice and works great, on 2M at least.
  • Dual USB ports, for keeping a phone topped off.
  • A cigarette lighter, for powering/charging a baofeng or anything 12V compatible.
  • Dual Anderson Powerpoles on the rear, for the ham’s favorite 12V connector
  • Uses a standard computer power supply cable.

So, here is my Bill of Materials:

A few build notes:

  • I crimped the powerpoles using my standard channelock wire strippers and then soldered them with my hakko. This gives about as good as a connected as you can get.
  • I used standard spade connectors (though mine are from Menards), again crimped and soldered, to connect everything to the power supply unit.
  • Most ham radios expect 13.8VDC, instead of the 12V this one was outputting. That’s okay, there’s a dandy reostat you can use to adjust the output power. I had mine set for 13.81V and its drifted to 13.84/5. I suspect it has to do with the construction and actually powering the unit up. However, my 857 will tolerate a +/- 10% range, so eh. I’ll adjust it again the next time I fire it up.
  • Take care when making the AC Mains connections. I am using a cut\trimmed piece of a PC power cord, with crimped and soldered spade terminals connected to the socket and to the power supply unit. I used some push on connecters to make a removable/solid connection to my socket, then put heat shrink over the arrangement to make sure I had removed and electrocution hazard, as best as possible. 14VDC will tickle, 120VAC will kill, and hurt the entire time.
  • Cut outs for the Chassis mount and PC powersupply socket were done with an x-acto knife, a ruler, and a little bit of caliper work. Everything fits perfectly. Lay out the holes you need, then visually check the marks are in the right place. Make light passes with the x-acto to cut through the plastic of the dry box.
  • This is such a gadgety thing, but it makes doing zip ties so much easier, tighter, and with practice the cut offs cleaner.

The total cost of the arrangement? Not counting the sundries I had on hand, $54.04. Not bad, a third of the cost and quite a bit more fun. You could do this even cheaper if you skipped the power powerpoles and the other features, but charging phones is good. When I first made it, I had the radio and a cut off power cord running directly to the power supply unit. It worked, and worked well, but I wanted to make things cleaner for sure.

Questions? Comments? Leave them below. 73, and good night all.

Edit: I posted this to /r/amatuerradio and generated a fair response. I would like to highlight Megas3300’s RF Choke. This is probably needed for mine as well, but so far I’ve only used this on VHF. A proper HF antenna system awaits.

Icom IC-W32A: A Work in Progress

2016-04-17
amateur radioElectronicssatellites
0 Comment

This is contingent to my “Workin’ the Birds” Series. However, it is a more technical discussion of amateur radio equipment. The primary purpose of this blog is preserve information I want for later. However, I feel that the information contained in these posts may be found edifying for others. If you can’t look up edifying, you are not the target audience of that secondary purpose. A third purpose is a demonstration of my technical skills and abilities as well as communication. It is not working as well as I would like.

I wanted an upgrade from my Baofengs for multiple reasons and the Icom IC-W32A is the radio that I ended up choosing. The W32A is well regarding within the Amateur Satellite Radio community as one of the best. After my post on the high price and poor selection of equipment available at this time, I ended up back tracking into the early 2000’s for my “new” gear. This HT is well loved. Wear spots, but no nicks or gauges. Used, but not abused. The only thing that was missing from what I wanted (better receive, reasonable price, better channel management, S-Scale) was better channel management, though there is the option of skip programming which may prove useful.

The bad is being an ebay radio (and 10 years old), I knew I would be needing a new battery. With this particular auction I didn’t get a charger either. At this moment in time, the charger missing is a bad thing. I don’t know if the radio will even turn on. While I was willing to risk what I did on the auction, I wasn’t ready to double the bill to fail. I need to know if this thing will power on and transmit. I was able to get around this though, with an adapter from RadioShack. Two options:

Since I have all of components for option 2, I went with that. The primary reason was the low cost – $3.50 and a bit of wire and solder. You could buy an official Icom Charger, but if this thing functions well, I’ll be switching to this lithium-ion battery pack. What a waste to get the official Icom option when I’ll use it … once.

After looking around the manual and talking with people on reddit and the AmSat mailing list, I was able to determine the polarity and power output of the plug. 12V, center positive.

After charging, the radio powered up! Oh joy. I at least have a reasonably priced scanner now. Except tuning to a NOAA Weather station, I do not have audio output. Plug in some headphones, and I have sound. Great. This could be either a broken speaker, or a broken headphone jack. Without the headphones, I have a working mic. With the headphones, I do not. For now, the solution is to find a reasonably priced handset to plug in. This will work until I have checked everything else out, and insure that the radio is worth my time to repair further. It will also provide inexpensive replacement parts. The replacement will be here Monday (4/18) and I will attempt to check into my ham club net with the radio that night.

That’s all I have for now. I’ll leave this post linking various resources and information that I found while waiting and getting the radio to function to this point.

Resources

Parts

Disclaimer:

Borrowing from my podcasts, this post is not sponsored by our employers, employees, who or what have you. All opinions expressed have been, are, and always will be our own. Said opinions expressed on the show are believed to be well reasoned and insightful. If you find a topic mentioned on the show interesting and decide on further action, then it is your responsibility to research, consult your doctor, lawyer, significant other, etc and understand the full risks of such an action. Providing a link to a resource online does not certify the usefullness, safety, or reliability of the content or providers on the other side.

The information in this post is semi-technical and capable of damaging\ruining\destroying your prized transceiver. It’s not my fault if you turn it into and efficient boat anchor.

Minor Update

I’ve found that filling a bit off the bottom of the plug from radio shack makes it connect more reliably.

Fixing Over-modulation in a Cheap Throat Mic

2015-09-22
amateur radioElectronics
0 Comment

I purchased this throat mic back in April. When I hooked it up to the UV5R, it was reported that I was over-modulating the mic. In layman’s terms, the mic was so sensitive that it was picking up my voice so well it was “overdriving,” or clipping the audio. You can see a fair example at the beginning of this youtube video:

So how to deal with the over-modulation in mics? If you have your Technician’s license, you know that this is one of the questions on the Amateur Radio Technician’s test. The answer is to move the mic further away from your mouth. But throat mics use a piezo element which translates vibration into an electrical signal. So, to work, they have to be touching the source of the vibration.

The solution is to dampen the vibration. One way to handle this is to rotate the throat mic about your neck so its not directly setting over your voice box. But, in my case, it wasn’t enough. To much low end in my voice, I suspect. In the end, the solution I employed was to put some theraband between the cup wall and the piezo element in the cup.

Theraband is basically rubber banding. Removed from sunlight, it doesn’t break down like a regular rubber band will do – an excellent quality for our intended use. Jorge Sprave uses it for his ridiculous launchers. I had some left over from a previous infatuation. If you don’t have theraband, you can use foam sheeting. I actually wanted to use the foam sheeting, much like this amazon product, but all I had was theraband. The idea was to reduce the amount of vibrations that the mic can “feel” by adsorbing some of the vibrations produced by speaking.

In the photo of the throat mic, the piezo element is located in that left hand cup. You can take it apart by removing the two Philips head screws on the inside of the band and gently pulling the cups apart. Then cut a piece or theraband or foam sheeting into a circle (a nickle is about the right size) and place it in the cup in between the piezo element and the inner wall that will be contacting your throat. Put the cups back together and then screw the screws back in. Be careful – the cheap plastic strips easily. I ended up needing to use some black electrician’s tape to hold mine together because I managed to strip out the screw holes and then lose one of the screws. I actually only needed a single piece of theraband to bring the mic into a usable range.

I used it to check into the local repeater net earlier, and heard no complaint. I’ll have to check with the fellow that pointed it out, but if I’m still over-modulating I’ll just place another coin sized piece of theraband between the cup and the piezo element. This is probably my favorite mic system to use. The acoustic tube makes for discreet listening and the mic needs to be directly on the sound source so it won’t pick up background noises.