UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Help needed with

3pinplug · 16th Aug 2022, 7:34 pm

Hi all
Fixed couple more dry joints and fired the unti up, started by first checking the output of the 3 voltage regulators in the power suply fitted to the back of the unit and got the following readings:-
MC7906CP
Input -10.6V
Output -4.6v?

MC7912CP
Input 19.0V
Output 12.4v

MC7924V
Input 33.8V
Output 23.5V

On the low 6V i desoldered a leg from each of the tants across the pins of the device and still get just -4.5V, I am thinking the MC7806CP may be defective as that is a little low - should i change this and or any others based on the readings?

16th Aug 2022, 7:34 pm	#24
3pinplug Pentode Join Date: Jun 2016 Location: Kent, UK. Posts: 190	Re: Help needed with - Racal Dana 9081 Hi all Fixed couple more dry joints and fired the unti up, started by first checking the output of the 3 voltage regulators in the power suply fitted to the back of the unit and got the following readings:- MC7906CP Input -10.6V Output -4.6v? MC7912CP Input 19.0V Output 12.4v MC7924V Input 33.8V Output 23.5V On the low 6V i desoldered a leg from each of the tants across the pins of the device and still get just -4.5V, I am thinking the MC7806CP may be defective as that is a little low - should i change this and or any others based on the readings?