Taylor/Windsor 45C VCM - UK Vintage Radio Repair and Restoration Discussion Forum

Deardsie · 2nd May 2021, 7:24 am

Hi all, I own one of these units. After years of it just sitting there I've decided to get it up & running. On switch on the pilot light illuminates but no movement on the meter. Does anyone know if there are replacement/equivalent meters available, or where I can replace the movement & keep the face plate. The windings appear to be over heated & there is no continuity across the terminals. Otherwise does anyone know the FSD of the original meter? Thanks in anticipation. Deardsie.

WME_bill · 2nd May 2021, 11:34 am

Taylor-Windsor 45C valve tester.
The meter is 250ua, 400ohm.
No replacement available. Equivalent as such unlikely. But a search on ebay will produce lots of meters. But sadly, they will tell you the scale calibration rating, and not the meter characteristics. And aim for a similar case size / scale length.
I have struggled in the past with other replacement meters, and had to buy several guessing the meter rating. You can always select one with a more sensitive movement, shunt it and put in a series resistor to match what is required. Usually a 100ua meter is 1 to 2 kohm. Makes an interesting exercise in Ohms Law and tests your lost maths skills. A 1ma meter (not suitable here) is 100 to 200ohm.
The scale is usually straight-forward to change, provided you can open the meter casing. Best to do this somewhere well away from workshop metal filings and dust and hairs. Be aware a MoD specification meter is often in a sealed case, which is difficult to open and reseal.
wme_bill

Vintage_RC · 2nd May 2021, 11:54 am

What makes you think the fault is the meter? there could be many reasons for no indication on the meter.

factory · 2nd May 2021, 1:47 pm

Probably the continuity check, but does the continuity range actually go high enough to measure the coil resistance? Try again on the resistance ranges if it doesn't.

The Taylor 45A, 45B, 45C all use a 250uA Model 400 meter, the earlier 45 (no letter) uses a 500uA Model 425 meter. There has been a couple of recent threads about the meters used in these.
They did sell the Model 400 panel meters on their own as well and use them in other test gear, but they may have different F.S.D. depending on the application.

David

2nd May 2021, 7:24 am	#1
Deardsie Diode Join Date: May 2021 Location: Sydney, New South Wales, Australia. Posts: 1	Taylor/Windsor 45C VCM Hi all, I own one of these units. After years of it just sitting there I've decided to get it up & running. On switch on the pilot light illuminates but no movement on the meter. Does anyone know if there are replacement/equivalent meters available, or where I can replace the movement & keep the face plate. The windings appear to be over heated & there is no continuity across the terminals. Otherwise does anyone know the FSD of the original meter? Thanks in anticipation. Deardsie.

2nd May 2021, 11:34 am	#2
WME_bill Octode Join Date: Oct 2007 Location: Exeter, Devon, UK. Posts: 1,554	Re: Taylor/Windsor 45C VCM Taylor-Windsor 45C valve tester. The meter is 250ua, 400ohm. No replacement available. Equivalent as such unlikely. But a search on ebay will produce lots of meters. But sadly, they will tell you the scale calibration rating, and not the meter characteristics. And aim for a similar case size / scale length. I have struggled in the past with other replacement meters, and had to buy several guessing the meter rating. You can always select one with a more sensitive movement, shunt it and put in a series resistor to match what is required. Usually a 100ua meter is 1 to 2 kohm. Makes an interesting exercise in Ohms Law and tests your lost maths skills. A 1ma meter (not suitable here) is 100 to 200ohm. The scale is usually straight-forward to change, provided you can open the meter casing. Best to do this somewhere well away from workshop metal filings and dust and hairs. Be aware a MoD specification meter is often in a sealed case, which is difficult to open and reseal. wme_bill

2nd May 2021, 11:54 am	#3
Vintage_RC Heptode Join Date: Sep 2018 Location: Twickenham, London, UK. Posts: 539	Re: Taylor/Windsor 45C VCM What makes you think the fault is the meter? there could be many reasons for no indication on the meter. __________________ Alan G6PUB, BVWS

2nd May 2021, 1:47 pm	#4
factory Octode Join Date: Jul 2009 Location: Cheshire, UK. Posts: 1,740	Re: Taylor/Windsor 45C VCM Probably the continuity check, but does the continuity range actually go high enough to measure the coil resistance? Try again on the resistance ranges if it doesn't. The Taylor 45A, 45B, 45C all use a 250uA Model 400 meter, the earlier 45 (no letter) uses a 500uA Model 425 meter. There has been a couple of recent threads about the meters used in these. They did sell the Model 400 panel meters on their own as well and use them in other test gear, but they may have different F.S.D. depending on the application. David