double flag pole , half pice 1953

Started by rajiv, October 07, 2017, 08:46:46 PM

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rajiv

are these type of errors are common errors ?

Director

Please post clearer pics in white light, so that everyone can see properly.

Thanks.

rajiv

Quote from: ASI on October 09, 2017, 12:24:10 PM
Please post clearer pics in white light, so that everyone can see properly.

Thanks.
hello ,the problem is , the coin is dipped in olive oil so it looks yellow , it is not yellow light . i try to post zoomed photos of the flags for   better  visibility .                   

Figleaf

Looks like an echo strike. If so, that is a common error for this period.

Peter
An unidentified coin is a piece of metal. An identified coin is a piece of history.

rajiv

Quote from: Figleaf on October 10, 2017, 09:39:47 PM
Looks like an echo strike. If so, that is a common error for this period.

Peter
what is an echo strike coin sir

Figleaf

An echo strike occurs when the pressure of the coin press has been put at a level that is slightly too high. At the moment the coin is struck, energy flows from the mobile die (the upper die) to the fixed die and beyond. The energy flows back to the mobile die, lifting it partly and "striking" the coin again, usually very partially. In fact, the irregular characteristic of the second strike separates it from a double strike, which can be observed all over the coin.

To observe how energy is transferred through matter, have a look at Newton's cradle. The solution of this mechanical problem is to absorb the energy below the fixed die, e.g. with a spring-like contraption.

Peter
An unidentified coin is a piece of metal. An identified coin is a piece of history.

rajiv

Quote from: Figleaf on October 11, 2017, 11:21:19 AM
An echo strike occurs when the pressure of the coin press has been put at a level that is slightly too high. At the moment the coin is struck, energy flows from the mobile die (the upper die) to the fixed die and beyond. The energy flows back to the mobile die, lifting it partly and "striking" the coin again, usually very partially. In fact, the irregular characteristic of the second strike separates it from a double strike, which can be observed all over the coin.

To observe how energy is transferred through matter, have a look at Newton's cradle. The solution of this mechanical problem is to absorb the energy below the fixed die, e.g. with a spring-like contraption.

Peter
thanks , although i could guess because of the word echo but you explained that echo strike to the fullest