UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio and TV Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > Specific Vintage Equipment > Vintage Test Gear and Workshop Equipment

Notices

Vintage Test Gear and Workshop Equipment For discussions about vintage test gear and workshop equipment such as coil winders.

Reply
 
Thread Tools
Old 16th Apr 2024, 11:16 am   #1
AussieRichard
Diode
 
Join Date: Oct 2023
Location: Newcastle, New South Wales, Australia.
Posts: 5
Default Taylor 45D Tube Tester Question

Hi All,

I recently purchased a Taylor 45D to have along side my uTracer3.

It was well used and needed a good clean of all the switches etc. Several resistors were out of tolerance as was the old capacitor C3. I did not replace any of the old diodes nor the shunt resistors R17 or R18 that are old wirewound resistors that measure fine. Anyway, after cleaning it up it seems to be working pretty well and compares favourable for mutial conductance with the uTracer.

However, it does not seem to compare well with the Anode current measurement where the Taylor 45D it is always much higher than the uTracer. The procedure I follow is to undertake a mutual conductance meassurement and then turn the red inner dial of the test selector to either 100mA or 10ma to measure the anode current. What I notice is that when I turn the inner red dial, even before pressing the Meter Test button, I see a a significant offset/deflection on the dial ? Is that normal ? I suspect not and there is some leakage either in a component or wafer switch ? Pressing the Meter Test button just increases the meter movement to a value above what I would expect or have measures on the uTracer.

Any help or advicer appreciated as to what may be the cause of this discrepency/issue would be appreciated.

Richard
AussieRichard is offline   Reply With Quote
Old 16th Apr 2024, 1:43 pm   #2
Cruisin Marine
Octode
 
Join Date: Jul 2018
Location: Worthing, West Sussex, UK.
Posts: 1,024
Default Re: Taylor 45D Tube Tester Question

I have a B version, so can only relate accordingly.
The "X" set level point appears in 2 places on the dial. You have to use the lower one if the set level cannot be achieved with the higher marked point on mine. This is all from distant memory, so I hope it makes sense.
__________________
"Behind every crowd, there's a silver Moonshine"
Cruisin Marine is offline   Reply With Quote
Old 16th Apr 2024, 2:37 pm   #3
AussieRichard
Diode
 
Join Date: Oct 2023
Location: Newcastle, New South Wales, Australia.
Posts: 5
Default Re: Taylor 45D Tube Tester Question

Quote:
Originally Posted by Cruisin Marine View Post
I have a B version, so can only relate accordingly.
The "X" set level point appears in 2 places on the dial. You have to use the lower one if the set level cannot be achieved with the higher marked point on mine. This is all from distant memory, so I hope it makes sense.
Thanks, I have no issues with the mutual conductance tests and the A and B set levels. My issue is with the anode current measurement.
AussieRichard is offline   Reply With Quote
Old 17th Apr 2024, 12:28 pm   #4
G4BZI Roger
Pentode
 
Join Date: Nov 2005
Location: Crewe, Cheshire, UK.
Posts: 138
Default Re: Taylor 45D Tube Tester Question

Richard,
I have a 45D tester.
When you turn the switch to measure anode current, you will get a reading which increases when you press the test button.
This is normal - there is always some anode current flow which increases when you alter the grid bias (which happens when you press the test button). The approximate anode current is the reading when the test button is depressed.
Hope that helps!
Regards,
Roger
G4BZI
G4BZI Roger is offline   Reply With Quote
Old 17th Apr 2024, 2:36 pm   #5
AussieRichard
Diode
 
Join Date: Oct 2023
Location: Newcastle, New South Wales, Australia.
Posts: 5
Default Re: Taylor 45D Tube Tester Question

Thanks Roger

I will try a few more tubes to compare with the uTracer but it does appear the anode current estimate from the Taylor is much higher in comparison, 50% to 100% when on the 10ma scale. What component is critical to the current measurement, one of the wire wound resistors?

Regards Richard
AussieRichard is offline   Reply With Quote
Old 17th Apr 2024, 4:33 pm   #6
David G4EBT
Dekatron
 
David G4EBT's Avatar
 
Join Date: Feb 2003
Location: Cottingham, East Yorkshire, UK.
Posts: 5,801
Default Re: Taylor 45D Tube Tester Question

I've had a Taylor 45D for quite some years and would concur with Roger's comments.

I've never given it any thought to it - I just press the test button and read off the result. Valve testers can become a hobby in their own right and the thief of time. You (when I say 'you', I really mean 'me'), seem to end up with valves for which you have no immediate or foreseeable use, then every now and then, when the mood takes me, I get the urge to pop one in the tester, search the book for the switch settings, test the valve and if it's close to the spec, I make a little label with the test result, pop the valve in a white box, or if its emission is low, bin it (which tend to be output valves, or those which seem to have relatively short lives like ECC85s).

I've recently tested an ECH35 and attach the results, which were close to spec. I've no means of knowing how accurate the 45D is, but I don't obsess about it. I suspect I'm not alone in only using it very occasionally and spasmodically. A bit of a rigmarole really, but it keeps me out of mischief. A couple of pics attached. (I could of course just scribble the results on the box - after all, that's what valve dealers tend to do, but I'm a bit of a fusspot).

The Valve Testing Databook contains the switch settings of many more valves than can be tested on the 45D without the addition of valve base adaptors, but I guess many who want to test valves are primarily interested in those used in amplifiers, maybe testing for matched pairs and only need the bases that are already on the tester. B9A I.O. Etc). I made six adaptors for B4, B5, B7, MO, UX5 & UX6 valves, which can be plugged into the I.O. socket on the 45D. Mostly only of use to those who restore 1930s/40s radios really.
Attached Thumbnails
Click image for larger version

Name:	ECH35 pic1.jpg
Views:	58
Size:	39.4 KB
ID:	296464   Click image for larger version

Name:	ECH35 pic2.jpg
Views:	53
Size:	38.3 KB
ID:	296465  
__________________
David.
BVWS Member.
G-QRP Club member 1339.
David G4EBT is offline   Reply With Quote
Old 17th Apr 2024, 4:41 pm   #7
G4BZI Roger
Pentode
 
Join Date: Nov 2005
Location: Crewe, Cheshire, UK.
Posts: 138
Default Re: Taylor 45D Tube Tester Question

Richard,


There are two meter shunts for 10/100 mA (40 ohm and 3.774 ohm respectively) and a pre-set resistor (500 ohm) in series with the meter - worth checking these - if you can measure the current with a separate meter (by breaking into the circuitry) that would tell you if the shunts and pre-set are correct>


Roger
G4BZI Roger is offline   Reply With Quote
Old 18th Apr 2024, 6:06 am   #8
AussieRichard
Diode
 
Join Date: Oct 2023
Location: Newcastle, New South Wales, Australia.
Posts: 5
Default Re: Taylor 45D Tube Tester Question

Quote:
Originally Posted by David G4EBT View Post
I've had a Taylor 45D for quite some years and would concur with Roger's comments.

I've never given it any thought to it - I just press the test button and read off the result. Valve testers can become a hobby in their own right and the thief of time. You (when I say 'you', I really mean 'me'), seem to end up with valves for which you have no immediate or foreseeable use, then every now and then, when the mood takes me, I get the urge to pop one in the tester, search the book for the switch settings, test the valve and if it's close to the spec, I make a little label with the test result, pop the valve in a white box, or if its emission is low, bin it (which tend to be output valves, or those which seem to have relatively short lives like ECC85s).

I've recently tested an ECH35 and attach the results, which were close to spec. I've no means of knowing how accurate the 45D is, but I don't obsess about it. I suspect I'm not alone in only using it very occasionally and spasmodically. A bit of a rigmarole really, but it keeps me out of mischief. A couple of pics attached. (I could of course just scribble the results on the box - after all, that's what valve dealers tend to do, but I'm a bit of a fusspot).

The Valve Testing Databook contains the switch settings of many more valves than can be tested on the 45D without the addition of valve base adaptors, but I guess many who want to test valves are primarily interested in those used in amplifiers, maybe testing for matched pairs and only need the bases that are already on the tester. B9A I.O. Etc). I made six adaptors for B4, B5, B7, MO, UX5 & UX6 valves, which can be plugged into the I.O. socket on the 45D. Mostly only of use to those who restore 1930s/40s radios really.
Haha, you have just described my behaviour perfectly David

Quote:
Originally Posted by G4BZI Roger View Post
Richard,


There are two meter shunts for 10/100 mA (40 ohm and 3.774 ohm respectively) and a pre-set resistor (500 ohm) in series with the meter - worth checking these - if you can measure the current with a separate meter (by breaking into the circuitry) that would tell you if the shunts and pre-set are correct>


Roger
Thanks Roger.

I have measured all 3 of these resistors in circuit as best I could (hard to reach) and they appear within tolerance. Servicing this device is a bit of a nightmare. I will try replacing the 40ohm and 3.774ohm resistors and/or breaking the circuit to measure current externally.

I have just created some new dial gauge scales for the controls using a software package called Galva. I have printed them as stickers so I will see how that looks. The decals seem to rub off even with mild glass cleaner.

Cheers
AussieRichard is offline   Reply With Quote
Old 30th Apr 2024, 11:58 pm   #9
AussieRichard
Diode
 
Join Date: Oct 2023
Location: Newcastle, New South Wales, Australia.
Posts: 5
Default Re: Taylor 45D Tube Tester Question

I pulled R17 and R18 out of circuit and they measure perfectly.

Not entirely sure where to break the circuit and measure the anode current ?

I am wondering whether the user manual is correct in relation to measuring anode current ? Do you need to depress the meter test button PB2 for the anode current measurement ? It is shown open in Fig 7 ?

Richard
Attached Thumbnails
Click image for larger version

Name:	fig-mutual-conductance.jpg
Views:	20
Size:	52.3 KB
ID:	297039   Click image for larger version

Name:	fig7-anode-current.jpg
Views:	21
Size:	58.0 KB
ID:	297040  
AussieRichard is offline   Reply With Quote
Reply

Thread Tools



All times are GMT +1. The time now is 3:45 pm.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Copyright ©2002 - 2023, Paul Stenning.