Do you receive the Mortgage value of a property every turn?
That's not how a mortgage works in Monopoly or real life!  A bank does not give you a perpetual income and ask you pay that amount plus 10% back once.  A Mortgage is a one-time loan based on the property value.  It is not a perpetual income.

The rules you need are all here. There is no reference anywhere that you get a mortgage value every turn.   


  MORTGAGES: Unimproved properties can be mortgaged through the Bank at
  any time. Before an improved property can be mortgaged, all the
  buildings on all the properties of its color-group must be sold back
  to the Bank at half price. The mortgage value is printed on each Title
  Deed card.
  
  No rent can be collected on mortgaged properties or utilities, but
  rent can be collected on unmortgaged properties in the same group. In
  order to lift the mortgage, the owner must pay the Bank the amount of
  the mortgage plus 10% interest. When all the properties of a
  color-group are no longer mortgaged, the owner may begin to buy back
  houses at full price.
  
  The player who mortgages property retains possession of it and no
  other player may secure it by lifting the mortgage from the Bank.
  However, the owner may sell this mortgaged property to another player
  at any agreed price. If you are the new owner, you may lift the
  mortgage at once if you wish by paying off the mortgage plus 10%
  interest to the Bank. If the mortgage is not lifted at once, you must
  pay the Bank 10% interest when you buy the property and if you lift
  the mortgage later you must pay the Bank an additional 10% interest as
  well as the amount of the mortgage.


Also think of the effect this would have on the game.  No one would ever lose.  Turn one I buy a property,  I then Mortgage it and I've an income every turn meaning I can't go bankrupt.  Every player would have all their properties mortgaged getting richer and richer so it would never end.