UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Hameg HM307-3 Cleaning and Repair

OldTechFan96 · 25th May 2019, 1:07 pm

TR121 B voltage: 5.3V.

The resistors around TR121 and TR122 are all fine.

I connected up two meters to the C of TR123 and TR124. Adjusting R223 (100Ω) had no influence on the voltage reading.

I removed it and measured 140Ω across it. It worked fine when I tested it with my Avo8. I'll have a look at the resistors around R223.

EDIT: Resistors all OK. Better get the FETs sorted before I bother with adjustments.

25th May 2019, 1:07 pm	#24
OldTechFan96 Octode Join Date: Jul 2017 Location: Newcastle Upon Tyne, Tyne & Wear, UK. Posts: 1,186	Re: Hameg HM307-3 Cleaning and Repair TR121 B voltage: 5.3V. The resistors around TR121 and TR122 are all fine. I connected up two meters to the C of TR123 and TR124. Adjusting R223 (100Ω) had no influence on the voltage reading. I removed it and measured 140Ω across it. It worked fine when I tested it with my Avo8. I'll have a look at the resistors around R223. EDIT: Resistors all OK. Better get the FETs sorted before I bother with adjustments. Last edited by OldTechFan96; 25th May 2019 at 1:20 pm. Reason: More info