Amb problem on Ep 1/8 race?

[superek4]

I just had a race on last sun 1st & 2nd final was fine but till the 3rd final almost all amb & even club amb has problem reading.

Change several club amb still have problem even personal amb have problem. The signal is too low.

Funny thing is the gp cars has no problems? Their 6v batt power their servos n amb? Whereas our only powered amb n our voltage is ranging from 14.8 to 22.2v?

Could it be electrial interferals? Never happened before for the whole year till now & it's 7 cars.