(*****) NFC antenna amplifier/Resonance Circuit V1 & V2.1

When these are listed and avaliable in the DT Store, I am going to petition Amal to name these

What should these Resonant Repeaters be called???
  • MFGC
  • Something, logical, boring, and sensible
0 voters

*If Amal chooses something different, I will still add MFGC as a hyperlink to the product


Wow, i really appreciate these stats. I actually never expected the data to reflect such an improvement over the V1 design. I actually assumed V1 would perform better considering the number of turns and guage wire. This is great.

The prototype board you have is going into production as well and that will most reflect the effectiveness of my flex version of the repeater (hopefully)


I must say, the testing was a bit more difficult due to the size of the disc.
I used my test rig for all the testing to keep it consistent, but the horizontal plane made lining up a bit more difficult. Lets just say, there was a little bit of juggling happening at times.
I should have prepped better

Sometimes I would get an amazing result, sometimes it was just OK.

I wasn’t going to post the results straight away, because, I think I can get some more consistent results off of the rig and testing vertically with a ruler standing upright
(The vertical vs. horizontal probably makes no sense to you all, but I’m not talking about polarization, but rather the physical lining up of the MFGC, the reader and the implant. )

You’ll note, the V2.1 on the phone I recorded ranges from 30-50mm
30mm was the constant, reliable and repeatable range, BUT I would get the occasional 50mm.
I believe this coincided with the phones duty cycle of high power NFC pulses (~1:5)
it happend too many times to ignore, but the 30mm is more what to expect.
Which is FUCKEN AMAZING by the way.

With the Flipper and Proxmark, due to the physical size of their antennas compared to the V2.1, there was the offset/overhang, which I think helped to improve performance.
I think for the proxmark (easy) a little recess for the V2.1 to mount into on a PM3 case would be a great setup and it could live there “permanently”

I think the V2.1 is too large to use with the Flipper as a fixed option.
My V1 sits between cover and casing and I have great improvements on read range.
You COULD make a slit in the silicone cover, and it COULD sit inside with an overhang, but this is really not practical.

Basically, what I am saying is, let me run this test again with some control measures in place, and real world applications.
By that I mean,
in my initial V1 testing, all my testing was V1 on reader, approach implant.
If you want even better ranges, you can achive these by placing the V1 or V2.1 on the implant and approaching with the reader.
In my opinion, this is less real worldy, It can be done, but I think you are better to leave you MFGC inside your phone case/ flipper case or mounted to the PM3 case, rather than removing it every time you want to read an implant.
Yes the read ranges are better with antenna on implant vs antenna on reader, but personally, I don’t think this is realistic in most instances.

What I expect in my next testing is:
A drop in some of the V2 figures, but in general, a noticable improvement on the V1 in almost all cases, which is inturn, a huge improvemnt on the naked readers.

I dont think people should get too fixated with the numbers, but rather be made aware, these are Mutha Fucken Game Changers, and you will not be disapointed with whatever version you get, and you too will be thanking Hamspiced and Satur9 for their great work.

Personally, I will be having a setup like this:

V2.1 will live in my phone case ( Thanks Spicey )
V1 will live in my Flipper case
A V2.1 will be mounted in a modified PM3 Easy case ( But this will be a “round to it” job to edit the file), But I will also look to mount a V1 inside my RDV4 case

NB: I havent even mentioned numbers with multiple MFGC… :smirk: :hamster_emoji_gif:

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That is awesome. Also a tad concerning from a defensive point of view. 50mm is still very close, but I can think of situations where I wouldn’t notice someone holding a phone that close to my wrist/hand (where as I would notice if they made actual physical contact).

I think anyone targeting you specifically would be using something s but more powerful from a less conspicuous modality like a backpack or something with a big reader in it.

Anything important should leverage additional security measures like passwords form your otp and fido 2 with pin set.

For sure. I was thinking things more like door locks. And for the Apex/FlexSecure a DoS bricking attack.

There isn’t near enough implant adoption for this to be much of a real concern. Usually there will easier ways for someone to gain whatever access they want if they are targeting someone specifically.

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Also, the stars need to be aligned to get the 50mm readings.
I would probably get 7-8 reads at 30mm before I would get a 50mm.
Also purely just reading a UID.
Not a full dump etc.
If they wanted that, it would take them a lot of


You and they would have to stay perfectly still and within very close proximity

200 (17)


Just a heads up, the Cyborg code only worked on the V2 Large, not the V2.1 Small. Dunno if that’s intended or not but just sent my order through anyways.

An oversight on my part as i just added the V2.1 small and didnt assign the code. its fixed now. Instead of you getting the discount im just sending you 2


Cool beans, thanks dude.

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Once I have them all, I will start some fresh testing for “all the repeaters”.

I have figured out a way to get more consistent results.

I have already made a start with VNA graphs of the repeaters I currenly have

[ I’ll just give some kudos to @Hamspiced, Dude, your tuning is BANG ON, which is why I think they work so well, and why they are MFGC ]


Thankyou @Pilgrimsmaster

This is the number 1 reason why there has been such a large time between each version release of these. I try really hard to get these tuned perfectly and then i even do a QC on each device i send out to make sure it is acceptable.

Each one of these repeaters has gone through multiple prototypes before i finally am satisfied with the tuning. It takes time to make my tweaks, then argue with the fabrication house engineers (it isnt something the engineers are familiar with, a device with no solder points and some empty layers). So each coorespondance looses a day of production because of the time change.

The V2.1S was a giant pain for me but not as much as the flex. The flex just had so many damn revisions… 4 panels at 36 test units means i have about 143 failed repeaters and 1 good one in flex.

to elaborate on the QC of the flex units. I thought it was really odd i was getting a 2-8% variance in tuning on these. Talked with @Satur9 about it because it made so little sense to me that there should be that much of a variance. His reply was eye opening.

If it’s not variation due to your coupling quality then it’s due to variations in the thickness of the polyimide substrate and the copper. Even microscopic changes can have an impact on the capacitance of the two plates and the inductance of the combined top and bottom coils. Also the annealed copper has somewhat random grain boundaries that can change the impedance which changes not just the capacitance and inductance but also the Q factor of the band pass filter.

It is indeed black magic, and the fact that we are able to get this precise in tuning is a remarkable feat and why i am so absolutely impressed with these that even the grain boundries of the copper that creates the capacitive plates can affect the tuning just blows my mind.