Notes for a DIY REM pod build

Some thoughts on a future DIY REM pod project.

a grayscale digital drawing of a (not DIY) REM pod with the words "did you find the ghost?"

I've mentioned this before, but I'm hoping to build some DIY paranormal investigation gadgets—starting with a REM pod—sometime soon. While I'm not quite ready to do the build quite yet, I wanted to go ahead and share my thoughts as I prep for the project.

Some of the information I found online about this build was a little technical and not necessarily written for someone like me (who barely has a clue what they're doing). So even though I haven't done the project yet, I figured my preliminary project notes would come in handy for anyone looking to do try this later on.

The REM pod is a common piece of ghost hunting equipment; the idea is that it emits a electromagnetic field, and it makes noise when something interrupts that field. So if anything gets too close, it makes a sound, alerting ghost hunters. And if no one was near the REM pod when it went off, and there wasn't other interference, then perhaps something paranormal might be interacting with the device.

If you clicked on the link in the previous paragraph, you'll know what I'm about to say: REM pods operate about the same way as a theremin, a musical instrument that a performer can play without touching, which was invented in the 1920s. There are some extra bells and whistles that REM pods add, like temperature sensors. But with REM pods frequently retailing for $170-200, many people opt to make their own from a cheap theremin kit.

My plan is to use the Madlab Junior DIY theremin kit, which seems to be the most popular way to do it.

My gameplan for building a DIY REM pod

To start, I am a rank amateur when it comes to building this sort of thing. I just learned how to solder a couple weeks ago, and I had mixed success with that. I was going to order a few more soldering practice kits, then I realized that many of those are more expensive than just buying the theremin kit (currently going for $12.99 on eBay). So I picked up a couple of those instead.

My plan right now is to basically use the theremin kits as additional soldering practice, with the hopes that one or both of them will be functional as of a REM pod. We'll see.

For my first sally, I'm planning to follow the instructions on the theremin kit closely, without trying to modify it or add any additional bells and whistles. I basically want to make sure that I can tackle the basic project before trying to do a more complex version.

Also, I think that after I've built it once, I'll have a better idea of how to incorporate the mods that people tend to do to bring their DIY theremin/REM pod to the next level. (Things like adding a better antenna, better speakers, and putting it in a housing.)

Pitfalls and challenges

That being said, I know there are also some pitfalls that I need to keep in mind. For example, multiple people online have mentioned that some of the theremin kits ship with faulty PCBs, missing parts, and other defective components.

The sense seems to be that at some point, the company was allegedly cutting corners. It's not currently clear to me whether that is still an issue, or whether that was resolved. But it does seem that it's possible I could correctly solder and assemble the components only to have created something that doesn't work.

If I end up with a nonfunctional device, I guess I'll have my work cut out for me when it comes to determining whether I screwed something up or whether there was something defective about the a component to begin with.

I have also encountered some requests for help online, where people have been trying to troubleshoot the devices because of different issues, like a too-small area of detection. I'm not actually sure how large the EM field should be for the theremin, but this person online seems to feel that there was a malfunction with their device that caused the field to be 1-3 inches. However, no one seems to have jumped in with an answer yet.

Issues flagged by Amazon reviewers

I did, however, find some troubleshooting tips and warnings in the Amazon reviews for the theremin kit. So I'd like to collect them here.

Doc Lykins from VaPES Paranormal Team in Virginia had a warning about how sometimes components are missing when you order the kit; they also mentioned the PCB issue:

I've received these kits before missing [things]. Please! Open your kit as soon as possible (over something to catch the items if they're accidentally dropped) and count/match the stuff. Since I build paranormal equipment sometimes weekly, I went on Amazon and ordered a kit with extra resistors/capacitors/diodes/IC's just incase some [came] up short. ...
On [my] last order I was missing a capacitor and resistor; I use these all the time in my builds, but also on the last one it didn't work correctly; all pieces were triple checked, and it may be a bad PCB board. 🤷‍♂️ I have extras for parts, but not the PCB.

One person mentioned that it's easy to get confused with the chips, so that's something to keep an eye out for:

the issue is the chips that you install. Two slots both fit so if it doesn't work correctly switch and or reverse chips. You can follow instructions or use wire connected to board and make a fancy box type as well.

One reviewer seems to have had issues with the build, at least with a recent build. It seems like this person has built it before without issues, but maybe a resistor or something went out here:

This product works soooo good but sadly it didnt work this time amd was smoking so fast idk y i used a 9v battery and poof !

Another reviewer says that there were unknown issues, which I would guess are maybe the PCB issue that seems to be cropping up. Also, one of the kits they received was partially built, incomplete return. That's one of many reasons why I ended up buying my kits on eBay. (Though also I try to avoid buying on Amazon in general, both for ethical reasons and for quality reasons. Oh, and also the kits were cheaper on eBay.)

The device didn't work properly and when it did it was hit or miss. Everything is properly soldered and even double checked it. Ordered 2 and the other one was a return that was already soldered with missing pieces

Though the Junior Theremin is marketed as a children's kit, one reviewer seems to think that it wasn't exactly for beginners:

unless you're experienced with mini-comp soldering, this board can be a bit tough. It's not very forgiving with mistakes and an iron too hot will easily melt the board.

Yet another reviewer ran into issues with missing parts:

They are good as long as the kits are complete.. I had a few that came with the same chip number not 2 separate ones, luckily I ordered several of these and some of the other ones had two of the same chips missing in other packs and was able to make all but 1 work out of them.. needs better QC!!

Multiple other reviewers mentioned issues with bad regulators and bad capacitors, or with builds that ended up working once and then fizzling out.

For example:

I buy these Theremins quite often. Buyer beware! It is hit or miss that they work! Out of probably 10 I bought 4 have maybe worked. Most the regulators over heat. I have even purchased additional regulators and still overheating. It must be the board. Get ready to order and return half!!!
Completed assembly. Double checked everything. After it wouldn’t work, we checked everything with a multimeter and determined capacitor 3 wasn’t functioning properly.

There have been also been claims of issues with the code:

Since the PIC processor came with the wrong code, the circuit was worthless. We could not use it for anything other than a negative add for the seller. The "instructions" for operation we found on line did not work at all. The circuit just beeps and burps and does nothing remotely similar to a Theremin.

So with all this being said, it sounds like there are a lot of things that can go wrong with this build. Also, it's worth mentioning that all these reviews are from 2019 to 2023. I believe the only 2023 review was a positive one, and most the negative ones were in prior years. But there were also positive reviews scattered and among the negative ones, so it was a little hard for me to tell how many people were getting faulty kits.

Also, for what it's worth, I did run the reviews through Fakespot, which seems to think that they were generally real reviews (it gave the listing a B, meaning "minimal deception").

Build notes from Amazon reviewers

The Amazon reviews for the theremin kit also contained some helpful details about the build.

Doc Lykins included detailed information about how to modify the kit:

If your building a REM-POD, you'd be better off with a small speaker instead of the one included. This goes for the antenna too. You'll need a scoping antenna with a male 3.5 jack, a 3.5 female to female connector, a single 3.5 jack with attached bare ended wire, hit glue gun, solder and soldering gun, a plastic 4"x 3" x 2" project box, plastic battery holder and I recommend a pack of different colored led's. Mine came with four blue. These are all pretty cheap on Amazon. Oh, a drill with small bits, too.

One review had a bit of info about how they built the housing and added their own antenna (they included images in the comments on Amazon—it looks nice!):

Yes this is the exact method used in rempods I built two here's what I bought 4.99 for 2 antennas with 3.5mm Jack's, and 3.5mm receiving Jack's that we're 5.99, I purchased 2 wooden round housings from Michael's crafts the lid opens they were 2.50 each, the kits were 17.95, at the time and I had wood stain linseed oil and epoxy resin already plus led lights so we'll say i spent no more than 56 dollars after taxes to build 2 units

Other options

With all of this in mind, I'm a little bit skeptical about how well these kits are going to work. I'm trying to think of them as soldering practice first and foremost, and something that maybe will get me some sort of approximation of a REM pod second.

If this attempt doesn't work, I did find a few other theremin builds online that seem like they could be easily adapted to become a REM pod.

For example, I found schematic diagrams of seemingly varying levels of complexity. I found an Instructable with info about building a DIY theremin using an Arduino Uno and open source PCBs, as well as another Instrucable with a different method. And there are definitely other options out there as well.

Next steps

There we have it. I can't say that reading the Amazon reviews fills me with confidence. I keep comforting myself with the idea that this is a kit intended for children, and I hope that as long as I have non-defective components, it'll at least sort of work.

Anyway, I hope that if you're considering this build, this collection of info was helpful. There are also plenty of YouTube videos about how to do it, including some about modifying home alarm tools (if I recall correctly) to work as REM pods, though I watched those a while ago and didn't save the links, so I haven't included them here. But if you Google it, you'll find it. (And maybe I'll do a follow up post with helpful videos later on.)

And if you've successfully built your own REM pod, I would love any advice and wisdom that you are willing to dispense, as I prepare to embark on this build.