Pingcoin

Pingcoin

About this app

Pingcoin is the digital version of the classical "ping test" for catching counterfeit coins. By recording and analyzing the sound produced by your coins the app is able to tell you if the coin is genuine or fake.

If you've ever found yourself not quite 100% sure about a coin's authenticity, try the ping test with the Ping Coin app. It will prevent you from getting fooled by counterfeit coins and it you will have peace of mind purchasing from even the shadiest coin sellers at fairs and garage sales.


How it works

A coin, like a musical instrument, produces a characteristic sound. Like a musical instrument this sound depends on its shape and on the material it's made out of. A wooden flute sounds different compared to a copper one. Similarly two coins of the same size and weight will sound differently based on the material they're made of.

The app will compare the characteristic sound of your coin (usually comprised of three frequencies) to my reference values. For each coin and for each frequency a tolerance threshold is displayed. If your coin's frequencies fall within the thresholds, it will almost certainly be genuine!

Important notes:

- The ping test works best as a complementary test to other tests. Do not rely solely on the ping test. Instead, combine it with a visual inspection and (ideally) weight and diameter measurements.
- Some coins of different composition, due to the variability in the coins' minting process and their natural wear, have practically indistinguishable sounds. A gold 1 oz Kangaroo and a silver 1 oz Kookaburra, for instance, will have practically indistinguishable resonance frequencies. Please note that this means that a test intended for one coin will work on the other and vice versa. This is why you cannot rely solely on the ping test.

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How to ping your coin

https://youtu.be/b4LbRGKTNiE

Pinch the coin at its center keeping the surface area of your fingers to a minimum. (Imagine that the coin vibrates at the sides but stays fixed at its center.) Then flick the coin with a finger from your other hand. This can be done very softly. Don't worry if the sound is shorted and muffled, your smartphone mic will pick it up anyway.

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Coins currently supported

- Gold South-African Krugerrand (1 oz)
- Gold American Eagle (1 oz)
- Gold Austrian Corona (100)
- Gold Canadian Maple Leaf (1 oz)
- Gold Great Britain Britania (1 oz)
- Gold Australian Kangaroo (1 oz)
- Gold Chinese Panda (1 oz)
- Gold Iranian Bahar Azadi
- Gold APMEX Round (1/4 oz)
- Silver Australian Koala (1 oz)
- Silver Britannia (1 oz)
- Silver American Buffalo (1 oz)
- Silver American Peace Dollar [alpha]
- Silver American Morgan Dollar [alpha]
- Silver Cook Islands Bounty (1 oz)
- Silver American Eagle (1 oz)
- Silver Somalian Elephant (1 oz)
- Silver Australian Kookaburra (1 oz)
- Silver Canadian Maple Leaf (1 oz)
- Silver Chinese Panda (1 oz)
- Silver Austrian Philharmonic (1 oz)
- Silver Australian Lunar Rooster (1 oz)
- Silver Tuvalo (1 oz)
- Silver Swedish 5 Kronor [alpha]
- Silver Franklin Half Dollar
- Silver Walking Liberty Half Dollar
- Silver Mexican Libertad
- Silver Morgan Dollar
- Silver Peace Dollar

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Submit new coins

Use the "Submit a coin" feature inside the app to submit a recording for a new coin to be added. Once the ping has been analyzed, the coin will appear in the list.

Any other feedback (send an email via the app) is GREATLY appreciated.

Ratings and reviews

I cant get it to listen long enough. As soon as i hit "start test" it listens for a split second then stops, as though it heard a ping. But there is no way there was enough time to even ping. If it would listen longer maybe id have time to ping a coin. As it is, it stops listening almost as soon as i tell it to start. At first, i thought it must be because i was in a loud room or something, maybe the AC or fan was interrupting it. But no, I turned all that off, it was absolutely quiet.

My original review is below, but since then the app is now working perfect for me, so bumped it up from 3 to 5 stars. Works great! I didn't see a trouble shooting section in the app, because my phone speaker(?) Only shows audio within the first of three resonance sections. I also tried a audio jack microphone, but the app still wanted to use the built in phone speaker instead. Nice app layout though.

Great app, much needed. I've used this successfully on silver Eagles, Morgan's and half dollars, but all the pre-65 quarters that I check only return the first 2 frequencies in range. Are quarters, being smaller, just not as easy to verify with a ping test? I'd assume dimes are even worse. Thanks!

What's new

- Add gold philharmonic
- Increased coin submission upload timeout to 20s