Marconi TF1041B - UK Vintage Radio Repair and Restoration Discussion Forum

Craig Sawyers · 30th Jan 2024, 10:53 am

There are a number of closed threads regarding this VTVM.

Anyhow, just acquired one in perfect mechanical condition, but with one problem, regarding the ohms range - it is impossible to set the meter for infinite ohms.

First scare from previous posts on this is loss in sensitivity of the meter movement.

However, on DC voltage the meter is bang on as compared with a Fluke DVM, both on plus and minus settings. And although I have not calibrated the AC probe (with the disc seal triode in it), it responds to finger touch on the 30V range.

It is possible to set centre zero just fine.

So whatever the problem is it relates only to the ohms range.

Before I take panels off and start checking stuff, is there any collective wisdom about said TF1041B not working correctly on ohms, but works on other functions just fine?

Craig

30th Jan 2024, 10:53 am	#1
Craig Sawyers Dekatron Join Date: Nov 2010 Location: Oxford, UK. Posts: 5,006	Marconi TF1041B There are a number of closed threads regarding this VTVM. Anyhow, just acquired one in perfect mechanical condition, but with one problem, regarding the ohms range - it is impossible to set the meter for infinite ohms. First scare from previous posts on this is loss in sensitivity of the meter movement. However, on DC voltage the meter is bang on as compared with a Fluke DVM, both on plus and minus settings. And although I have not calibrated the AC probe (with the disc seal triode in it), it responds to finger touch on the 30V range. It is possible to set centre zero just fine. So whatever the problem is it relates only to the ohms range. Before I take panels off and start checking stuff, is there any collective wisdom about said TF1041B not working correctly on ohms, but works on other functions just fine? Craig __________________ Doomed for a certain term to walk the night