Using AI to combat RFI in a power supply

Followers of my rantings will have seen this post where I talk about the issues I am having with a cheap switch mode power supply unit (SMPSU) and its interference with my radio reception.

Just for grins I thought I'd try asking Claude.AI for advice on mitigating this RFI. What it told me went against everything I had been taught about combating RFI in the radio shack.

Let's start with some pictures. The first picture is of my Afedri SDRNet Software Defined Radio tuned to the low end of the Medium Wave (AM) broadcast band. I am using GQRX as the front end. You can see quite a number of very aggressive signals that are not desired.

If you look at the waterfall above (the blue/yellow bit) one can clearly see very strong individual single carriers that in some cases are louder than my local radio stations at over -35dB.

How do I know that this particular SMPSU is responsible for this RFI? When I unplug it this happens ...

What a difference!!! No change in my noise floor was observed. It normally sits around -95dB. I live in a significantly urban area and so my neighborhood is filled with other peoples electronics devices which add to the noise floor. 

So how do I fix this? Conventional wisdom dictates that I build a filter and apply it to the output of the supply before it connects to my radio equipment. In this case however, my SDR is not powered by the switch mode power supply. So where is the noise coming from? Again, conventional wisdom tells us that the interference is radiating along the wires connected to the output side of the SMPSU and then being picked up by the antenna on the SDR. This appears to be correct as disconnecting the antenna from the radio produces no RFI issues. Adding an AM band stop filter significantly reduces the RFI and its related harmonics (iterations of the interfering signals that flood the radio all the way up to its maximum range).

Note how the noise floor has dropped 25dB and so have the FRI signals too. Clearly they are being received by the radio over its antenna. Lets remove the filter and perform one final test. Lets disconnect the wires from the output side of the SMPSU.

Yes, removing the wires from the output side of the SMPSU also removed the RFI. Removing the filter also increased the noise floor by 25dB. So we can surmise that conventional wisdom is correct in that the RFI is indeed leaking out of the SMPSU via its output wires.

So to recap our findings; 

• The Switch Mode Power Supply Unit (SMPSU) is creating RFI
• RFI is being radiated on the wires connected to the SMPSU output
• The band stop filter is not sufficient to combat this RFI

So lets ask Claude. I asked the question "How might I mitigate the RFI being emitted from an cheap switch mode PSU?". After a second or so of thought Claude responded

Great practical question! Here are the main mitigation strategies, roughly in order of effectiveness and ease of implementation:

1. Input EMI Filter (Most Important)

As discussed, this is your first line of defense. You can:

• Buy a pre-made IEC inlet filter module — these are cheap (a few dollars) and combine X/Y capacitors and a common-mode choke in one package. Simply wire it between the mains and the PSU input.
• Look for ones rated at the PSU's current draw with attenuation specs in dB across the frequency range you care about.

2. Common-Mode Choke on the Input

If you want to go further, add a toroidal common-mode choke wound on a high-permeability ferrite core (Fair-Rite, Wurth, TDK all make suitable cores). Wind both the live and neutral together through the same core — this attenuates common-mode noise without affecting the 50/60Hz supply current.

3. Ferrite Clamp-On Cores

The quick and dirty approach — snap ferrite clamp-on chokes onto the input cable as close to the PSU as possible. Multiple cores stacked together increase attenuation. These are the things you see as lumps on laptop power cables. They won't fix a really bad PSU but can take the edge off.

4. Shielding the PSU

• House the PSU in a grounded metal enclosure if it isn't already — this addresses radiated RFI rather than conducted.
• Ensure the shield has a solid, low-impedance connection to earth ground.
• Any gaps or apertures in the enclosure should be smaller than λ/20 of the highest frequency you're concerned about.

5. Output Side Filtering

While less effective for RFI back into the mains, adding filtering on the DC output helps protect sensitive downstream circuits:

• A pi filter (capacitor → inductor → capacitor) on the DC output rail
• Keep the inductor value modest (a few µH) to avoid instability with the PSU's feedback loop
• Use low-ESR capacitors

6. Proper Grounding and Cable Routing

• Keep input and output cables physically separated — they can couple noise back if run together
• Use shielded cable on the output if running to sensitive equipment
• Ensure a solid single-point earth ground

7. Replace the PSU

Honestly, with very cheap PSUs, the economics sometimes favor just buying a better unit. PSUs from reputable manufacturers (Mean Well, for example) are already designed with proper EMI filtering built in and have passed regulatory testing. A Mean Well unit costs only slightly more than a no-name unit plus the remediation parts.

---

Practical Approach

If this is a specific interference problem you're troubleshooting, a good workflow is:

1. Start with a clamp-on ferrite on the input cable — costs almost nothing and takes 30 seconds
2. If insufficient, add a pre-made IEC EMI filter module
3. If still problematic, add a metal enclosure with proper grounding
4. If you're still fighting it, the PSU is probably beyond economical remediation — replace it

It appears Claude thinks the issues are on the INPUT side of the SMPSU. This goes against conventional thinking. The mitigation was broken down into 4 manageable steps. Lets try them.

1) "Start with a clamp-on ferrite on the input cable". You've seen these a everywhere. You probably have some knocking about in your junk box. I have a large stash of these collected over the years from other projects or junk sales. I'll install 1 on the input side power cable and if it works we should see some drop in the level of the interference which is currently over -35dB.

As seen on the left I added a single clamp-on ferrite. It did actually do something. We've gone down from -35dB to about -53dB (see above). Lets round it up and call it -55dB. That's actually a significant improvement. 20dB is around a quarter of the original signal. However, its still too much by a long way. I tried adding more clamp-on ferrite's but it seemed to make no difference.

While doing this I also noted that when the output cables are connected but yet the powered devices are not yet turned on there is no RFI. Only when the powered devices draw current does the RFI appear. This sent me down a short rabbit hole to see if it was in fact one of the many devices (mostly Raspberry Pi's based SDR's) powered by this SMPSU.

So on to step 2, "Add a pre-made IEC EMI filter module". I found this device on Amazon which was promptly ordered. As the SMPSU does not have an IEC plug I bought one with pigtails. Lets get it installed.

No discernible difference. Arguably things got worse by 10dB. One of the important things to note with the EMI filter is that while it has 3 incoming conductors it has only 2 outgoing conductors. The ground is not presented for connection to the SMPSU. Lets try "yoking" the ground and connecting it back onto the SMPSU.

Maybe one or two dB's of improvement with the earth attached but its hard to tell. Certainly not the improvement I was looking for. 

Step 3 says to mount it inside a metal enclosure. The SMPSU already has a metal enclosure. I opened it up to check it was grounded and it is. 

So that leaves Step 4: "the PSU is probably beyond economical remediation - replace it". Hmm. Does Claude have shares in a PSU factory? This is not a possibility for me due to financial constraints.

So has Claude failed to mitigate my RFI issue? Why did it not offer me some output/DC side solutions? For now I'll chalk this up as an AI fail.

 

Switch Mode Power Supply Noise

I am the owner of quite a few 12VDC power supplies. All of them are switch mode type. Among the many I own is an Alinco 40A supply that was built with Amateur Radio HF operating in mind. As such it produces very electrical little noise that can be detected by my various ham radio receivers. That cannot be said for the other supplies. Most of which look like the one below.

I recently moved much of my radio shack onto the wall in the garage and that required me to also mount the power supply on the wall. The supply would drive not only a handful of radio's but also an ever growing farm of Raspberry Pi computers as seen in the image below.

In this picture we can see the Raspberry Pi farm as well as a few radio's. What you cannot see is my Afedrfi SDR-Net network attached SDR HF receiver and the AllStarLink system I host for the Marple-Newtown Amateur Radio Club. All of these systems and receivers are powered by a no-name Chinese 30Amp switch mode power supply like the one pictured above.

HF operations in the house have recently been plagues by a large amount of electrical noise. I had my suspicions as to where it was coming from and so started an investigation to prove my theory. My first test was to document the noise level under "normal" conditions. This would be where all the radio's and Raspberry Pi's are powered by the 30A supply. Using my SDR receiver connected to my copy of the GQRX Software Defined Radio tools I was able to take a screen shot of the entire 40 meter amateur band and also quite a bit of the 41 meter broadcast band too.

In the above picture we can see a uniform interference pattern every roughly every 50KHz or so. This interference is found all the way up the spectrum from below the AM broadcast band to well after my receiver caps out at 45MHz. It it strongest at the low end of the bands and diminishes (but does not disappear) at the top. Below is my a capture of my local AM radio spectrum.

So now that I have a baseline I elected to turn off the supply and replace it with one of my camping batteries. I expected a very quiet spectrum response. I was not disappointed. As you can see, a significant drop in the noise levels. Look carefully and you can make out not only proper AM carriers but also IBOC carriers too.

Further up the bad there is almost no electrical noise at all.

Changing to a different no-name brand of supply we get this.

Not as bad as the first supply but not great either. But it diminishes quickly as the frequency gets higher.

I am led to believe that the Meanwell brand of switch mode PSU's upon which most of the ones I have are clones behave much better. I have yet to experience this as I do not own one. However, they are currently (pre-Trump trade war Tariffs) only around $40 so I am trying to obtain one. 

Weather Satellites Round 2

Back in 2014 I described a weather satellite receiving station that I had built with one of the last remaining RIG RX2 receivers ever sold. They went on sale to clear out the inventory and so I bought the last 5. Most of them went to local schools. I had been a Remote Imaging Group member for quite some time ever since the launch of the RX2 and indeed created a few mods for it along the way. I've been chasing this particular demon since 1997

Back then things were pretty primitive. A wideband FM receiver tuned to 137.5MHzish fed audio into a computer. Some software then listened to that audio and decoded a fax. And that was it.

Modernizing an RX2 to Y2K technology levels

In the picture above we can see my attempt at updating the RX2 to Y2K level technology. I've created a breakout board (under the LCD) to make accessing the various signals coming from the multi-pin header on the top right of the green board easier. I've also added an ATMega328 (of Arduino fame) on its own board to drive the LCD. The original RX2 had a single 7 segment LED display to display its channel number. The "dot" on the display was used to indicate that the receiver was in scanning mode. I wrote a bit of code that looked at the various lines of the LED to see what channel number it was currently on and then transposed that into some LCD display text. It was a total hack but it worked very well! I also converted the RS232 control port to USB.  

Well that was then. Between then and now I've moved house a few times as well as stupidly lost my RX2. But that has given me the opportunity to upgrade my receiving station to more modern technology. Today one would use a USB based Software Defined Radio and a Raspberry Pi or similar computer. 

RTL-SDR USB Sticks

There are 2 of them screwed to the wall in the above picture. Simply feed them with the correct antenna, plug them into a computer (I'm using a Raspberry Pi 3), configure the software and then wait for the satellite to go by.

Speaking of antennas, here's a picture of a very simple to make linear polarized antenna that I made from a broken steel measuring tape. It's simply a few lengths of the tape cut to length (520mm/20.5") and then attached to some coax. I used my 3D printer to create a mounting point for all of the elements. The antenna behaves just like a turnstile type but with slightly less gain.

This antenna is called a V-Dipole. It is a basic dipole antenna but its elements are pushed forward so that it creates a 120 degree V shape. As with any dipole, one side is known as the "driven element" and connected to the inner of the coax while the other side is known as the "counterpoise" and is connected to the coax shield. By placing the driven element on the right hand side of the antenna we can create an antenna that is still linear in design but has some limited emulation of Right Hand Circular Polarization (RHCP). By placing the driven element on the left we can emulate a Left Hand Circular Polarized (LHCP) antenna. Ha! And you thought making antennas was hard!?

Upon closer inspection of the picture to the right it would appear that an antenna element is missing. Not so. The reflector elements below the main antenna must all be connected to the coax shield (there's a wire running up the back of the pole for this) and must entirely encircle the main antenna to create the illusion of a full circle. The reflector is not necessary but does improve the antenna's reception ability by as much as 3dB so its worth doing.

There's about 75 feet of RG8x coax connecting the antenna from the roof of my apartment building to the receiver on the wall in the garage. According to the many online coax loss calculators the coax presents an approximate 3dB loss in signal level. 3dB is roughly half of the signal lost to the coax and significantly diminishes an already weak signal (it has come all the way from outer space!). 

To counteract this loss I found a VHF preamp in my junk box. It is a very old kit from a long defunct but popular electronics kit supplier. This item was designed for use on the 145MHz amateur radio band but its input filter can be tuned over a range of about +/- 25MHz and so I "ghetto tuned" it to the 137MHz weather satellite band using my SDR software looking for a peak in the noise floor.

The picture on the right shows my SDR software tuned to the 137MHz weather satellite band. It's a little hard ot see but there are 3 blue stripes in the bottom right corner of the picture. The aim was to make this blue stripe (known as a "waterfall") brighter. The waterfall descends in real time down the screen. The lower part of is the before where the preamp's input filter was tuned to an unknown frequency. The middle part is where my tuning stick was inserted into the adjustment coil on the filter. The top part is a little brighter than the "before" waterfall. You get the idea. Fiddling with the coil moves the preamp's reception window up or down in frequency. As we say in ham radio, "tune for maximum smoke". Peaking the filter on a signal is very difficult but increasing the noise floor is somewhat easy with the right tools.

Here's the finished article wrapped in marine heat shrink and installed into the coax just below the antenna on the roof. In theory the preamp delivers an added 20dB of gain and so should more than overcome any coax losses and maybe even add a little improvement to the desired signal.

All the hardware is now built so I guess its time to talk about software. I'm using a Raspberry Pi 3 that I also found my junk box.

Poking about on the Interwebs I came across a project called raspinoaa which is a fully self contained satellite receiver and decoder that uses all the hardware I had in the junk box. It also predicts when the weather satellites are coming and schedules their capture. Finally, it decodes the captured data and creates a web page to display them on. Below is a captured picture from NOAA 18.

I can also capture the Russian Meteor series of satellites These are digital satellites with much better picture quality. They use the LRPT system. However, my antenna is a little weak for this and so I only get partial amounts of data as seen below.

This project was built exclusively from my junk box. I did not buy any parts specifically for it. Obviously at some point in the past I had bought all the components. They were bought for other abandoned projects. The total cost of this build would be about $100. If you want to take a look at my most recent captures and see when the next passes are going over my apartment point your browser at http://wx.ni2o.ampr.org/wxsat  

RadioShack PRO-2055 scanner discriminator modification

I own one of these scanners. It is a bit long in the tooth now but back in its day (early 2000's) it was the top of the line scanner sold at the now mostly defunct RadioShack. So now that its well out of warranty and without much use for it I decided it was time to do the discriminator audio modification.

This modification will take the pre-filtered raw audio and present it via a socket on the back of the radio for later use by sound card or SDR software. Such uses could be for receiving Weather Satellite data around 137.5MHz. Both APT and LRPT are possible due to the bandwidth available. Some 50KHz of audio spectrum (+/- 25KHz) should be usable thereby overcoming issues of doppler shift. 

Its a simple modification requiring only 4 components; 6 inches of RG174 type coax, a 0.002uF (202) capacitor, a 10K resistor (Br/Bl/Or) and a 3.5mm (1/8") mono panel mounted headphone socket.

Remove the radio from its black enclosure sleeve. Remove the top and bottom covers and disconnect the speaker by pulling the connector from the board. On the component side of the board locate TP4. It is located next to a small 8pin surface mount IC. Follow the black coax in the below picture to locate TP4. Solder the inner of the coax to TP4 and the outer/braid to a suitable ground point. I scratched off some of the solder resist to reveal a large copper ground plane and put the braid there. Run the coax through the large speaker hole to the other side of the board.

Take a look on the back of the radio. You will see a few factory made holes including one marked for an M5 screw. As if by magic, the 3.5mm headphone socket will install just nicely into this hole. No drilling required.

With your socket mounted solder the 0.002uF (202) capacitor across the positive and ground pins. Solder one end of the 10K (Br/Bl/Or) resistor to the positive pin. Finally prepare the remaining end of the RG174 coax and connect the inner to the end of the resistor that is now sticking out from the socket. Connect the braid to the ground pin together with the other end of the capacitor.

Check your work for shorts and dry joints. Reassemble the radio making sure to re-attach the speaker connector. Power up the scanner and test that it still works as before.

Adventures in WeFAX

One of my "go to" frequencies for testing my HF equipment is 6338.6KHz USB. There I will usually find the US Coast Guard's WeFAX service pushing out weather information in FAX format. This is a time tested way to send weather maps and printed statements to ships at sea. And yes, FAX machines are still a thing.

My local WeFAX transmitter (callsign NMF) is up in Boston and so presents an approximate 300 mile distance between me and the transmitter. This would be about the same if I were a ship at sea. 

NMF transmits on a handful of frequencies depending upon the radio conditions and the time of day.  Today I decided to try their 12750KHz frequency (a first for me) to see if it would yield better pictures than I have been able to receive lately. With the rise in solar activity and the local electrical noise around here 6338.6KHz (dial) has been a tough catch.

A broadcast schedule received from NMF

As if by magic I am receiving an interference free (if a little blurry) FAX message. As the day goes by one can receive all sorts of written weather statements and pictures. They even send out satellite pictures too. A schedule of all the world wide FAX transmissions can be found here.

I am using my FT-710AESS HF transceiver and the FLDigi software. But "hold on" I hear you say. "The radio is tuned 1.9KHz lower than the frequency published by the USCG". Why yes it is. It's a USB signal with its tone pair centered on 800hz. In order to receive both the mark and space tones (it is data after all) one has to tune down in frequency so that the tones fit into the pass band of the radio. The accepted tuning offset is 1.9KHz giving a tone pair frequency of 1500/2300hz.

FLDigi software

FT-710 receiver

Follow this link for an explanation of how to receive these pictures. It's pretty easy.

Satellite Exploits

 This is a reprint of a few pages from my old g7ltt.com website originally posted in 2002 ...

Firstly lets look at my station. I own the ubiquitous Yaesu FT-847 transceiver. This radio is very commonly found in the stations of many a satellite enthusiast. I have beam antennas for 2mtrs, 70cms and an MMDS down-converter with dish for 13cms (2.4GHz) all of these antennas are mounted on a cheap azimuth and elevation rotator arrangement by Satelectronics.

I have owned this radio for about a year with the intention of getting active on the satellite bands and was finally able to install my antenna system onto my new house in the early summer of 2002. All was not well. I bought one of the first Sat-El rotor systems that were made and it came with a few surprises. Firstly, the software was severely lacking. So much so that I took to developing my own program so that I could make my satellite prediction software control the antennas. QA was also a serious issue. One of the 2 rotators wouldn't work. After several trips to the roof and almost 6 weeks in waiting I finally got a replacement rotor. Having proved that the new one worked I took it apart to compare it with the broken one. The broken one was missing a very large capacitor! It never worked so how could it have passed the manufacturers QA process?

Aligning the antennas was another pain. The antennas must be accurately mounted onto the rotator so that when the rotators think they are looking at the Pole Star the antennas are too. In this way whenever the software controlling the rotators wants to look at a given point in the sky the antennas will correctly look there. This was not an easy task. It took me almost 6 months to complete this stage of the alignment. I couldn't seem to get the rotators to line up with anything.

A few nights ago I was watching "The Dish" on video. Its the story of the Parkes Radio Telescope in Australia. This was the dish that brought the TV pictures of Neil Armstrong's Apollo 11 moon walk back to the world. The story told in the movie is apparently true and it chronicles the goings on during the 2 weeks around the moon walk. Parkes was the only dish in that part of the world capable of receiving the pictures as the moon was only visible from Australia at the time. Well Parkes computer had a problem just a few hours before the big event and they lost contact with the space craft. After an hour of bluffing NASA about land line problems they finally found the space craft by randomly pointing the dish at the moon and waving it around a bit. This gave me an idea!!

So picture the scene. Its 10:30PM. Its dark. Its DAMN cold. The moon is out. Mark is on the roof trying to work out why his antennas are not pointing at the moon when he tells them too. I figured that I could align the antennas with the moon as my point of reference rather than the Pole Star. I can see the moon. I don't know what the Pole Star looks like. I start by guestimating the amount of error between my antennas and the moon's location. I guess 20 degrees. I go down to the basement where I control them from and fiddle with the settings. I go back up onto the roof. I reckon I made it worse. I go back down to the basement. And so on for about half an hour.

I'm getting cold and annoyed. It's getting late and the neighbors dog keeps barking at me up on the roof. I retire to the bedroom to spend some time with my wife before she forgets what I look like. On the way I fall over my laptop computer. A light goes on! I have a wireless network card in my laptop and some remote control software on my computer in the basement. Quick as a flash I'm back on the roof with my laptop. Now I can see what I'm doing!! Within about 5 minutes I was able to align the antennas so that they pointed at the moon. As the antennas are only about 6 feet above the roof of my house I was able to look from the back of them up to the moon and see that they were perfectly lined up. Back down the ladder and off to bed.

Sunday morning and I'm up early and down in the shack. I run up Nova (satellite tracking program) on my computer and find that I'm just in time for a PacSat pass. I instruct my antennas to point to it. A quick check of  Amsat's Operational Satellites page tells me what frequency I need to listen on. Sure enough, there's a whole bunch of data being transmitted. Result! My antennas are looking at a satellite. I don't have anything set up do receive the data so I just listen to it. Not quiet 10 minutes of data was heard here at KC2ENI QTH.

Next up was a crack at AO-40. This is what I started building my satellite system for. I have an MMDS down converter and a 3 foot BBQ grill dish (more about this here) which allows me to listen to the 2401MHz band. This is where all the activity is now as AO-40 has had some sort of unexplained accident which killed off all its other facilities. Sure enough when the satellite came around later that day I was hearing some hams sending each other SSTV pictures. I tried to decode the pictures but I wasn't able to get a good enough signal from the satellite. I was able to decode the telemetry beacon with some success as you can see from the screen capture above.

You can see I was only getting about 40% of the data packets from the telemetry beacon. I'm not sure quite why that is but I suspect that it has something to do with interference from all the 2.4GHz (2401MHz) gizmos we have around the house like our wireless network and some CCTV cameras.

On the next pass I'll turn all the 2.4GHz stuff off and see of it makes an improvement on the telemetry. If so it looks like I'll be spending a lot of time hard wiring the network devices to the main switch here in my shack.

Upgrade your old TNC to a USB interface

With the current resurgence of Packet Radio I decided to dust off my old Packet Radio Terminal Node Controller (TNC). There were untold thousands of these made in the late 80's and early 90's and to this day can be found at junk sales and hamfests for very modest prices.

One of the issues facing us today is that these modems typicaly used an RS232 serial port to communicate with the host computer. Take a look at your computer. Do you have an RS232 port? Most likely not. They have gone the way of the printer port and the dinosaur. Everything has moved over to USB.

The upgrade is very easy requiring only a USB-TTL interface commonly used to program the Arduino and other like microprocessors. The interface connects to the TTL facilities on the rear of the TNC.

The wiring is trivial. Using some female DuPont connector wires connect the 2 devices together as follows...

USB                             TNC

GND -------------------- GND

TX   -------------------- TX

RX  --------------------  RX

Set up your terminal program to reflect the port and speed settings reqired by your TNC then turn it on.

Adventures in QRP

 I've been slowly getting my QRP portable station together. Just before having brain surgery I bought an mcHF QRP radio kit from M0NKA (not a clone or Chinese built rip off). My idea was to build it while recovering from the surgery as a way to prove there was no lasting damage. Things did not go quite to plan and only now some 3 years later am I finishing the radio. Along the way I lost some of the parts including the knobs and the rubber buttons. It also didn't quite work when I gave it a test drive.

Suspecting shoddy workmanship on my part I went back over my work. As far as I could tell it was all good. In conversation with the gang over on the mcHF mailing list it was suggested to me that it might not be my work that's at fault and to check the factory installed components too (the kit comes with many surface mounted parts pre-soldered). Following the alignment procedure I was able to track down the issue to the band pass filter arrangement. I again checked that I had wound the filter coils properly and that they were connected to the PCB. I then progressed to the pre-installed relays that switch the various filters off and on. BINGO. Dry joints abound. Re-flowing the relay's solder joins with my iron yielded a working radio.

I was able to buy some rubber buttons for the radio via eBay but not the knobs. Owning a 3D printer is often a bonus in situations like this. A quick search on thingiverse.com revealed quite a large collection of parts for this radio that I could print including some knobs. That problem is now solved. I later printed a matching tuning knob so that all the knobs are the same colour.

But what about an antenna? In the end I decided to build this one from a radio club that's based in Hawaii. Its a simple end fed random wire antenna with a 9:1 transformer to help with the matching.

This really was a junk box build. I recovered the iron core from an old UPS that my employer was throwing out. In its previous life the core was part of the 24-120V inverter circuit. I was even able to reuse some of the wiring from the old UPS to wind the transformer onto the core.

Again, my 3D printer was pressed into service. Trolling through Thingiverse.com again I was able to find an enclosure for this part of the project. I added 35 feet of speaker wire that was kicking around and was able to complete the project with other supplies form my apparently well stocked junk box. The only thing I had to buy was #6-32 nuts and bolts. They were just $1 at the local WalMart.

Here's a video of me testing the whole setup from the parking area at the back of my apartment building. 

I have this LiFePO4 battery which is about half of the weight of other lead acid batteries of the same size. Plus, its LiFePO4 technology which will actually save me money in the long term as I'll get more life from it. 

I think I'll be printing this carrier for the battery too.

Some IC-7300 pics ...

I bought Harbor Freight "pelican" style case for my Icom IC-7300. The radio can now get dragged around in the back of the car and taken camping etc without fear of damage.

FT-817 Go Box

I've had this kicking around for a while. Before I put it up for sale I thought I'd show you all my FT-817 Go Box.

It's built around a Harbor Freight "pelican" style case and contains everything needed to operate the radio in any mode. Just add a battery. The photos are pretty self explanatory.