A customer was having ADF trouble,the unit just didn't seem to work very well most of the time .It would point ,but the needle was very slow & the range was not good.Sometimes it seemed to work fine.Then it went to shop,after some time it worked perfectly well in the shop.But in the aircraft it didn't perform well ,so he has checked other things ,such as loop & sense antenna & the wiring to the antenna, he then checked the battery voltage of the aircraft. Everything seemed fine so what could be the cause????????
The trouble was found to be low voltage but not the battery voltage; the voltage appearing at the input of ADF itself was low,even though the battery was all right.
There was loose connection at the Circuit Breaker that supplied power to the ADF;when this connection was tightened ,everything worked fine.
The connection does not have to be very loose to cause a significant voltage drop.To check this kind of problem the voltage at the unit must be checked with the unit operating .If the voltage is measured without the equipment operating there would be very little current flowing & there would be no appreciable voltage drop & the condition would not be detected.
Battery---------------BUS ----------------------CB-------------------ADF
12V 12V 9V
loose connection
(Loose connection high resistance & voltage drop occurs)
nice blog sir.
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