UK Vintage Radio Repair and Restoration Discussion Forum

UK Vintage Radio Repair and Restoration Discussion Forum (https://www.vintage-radio.net/forum/index.php)
-   Vintage Test Gear and Workshop Equipment (https://www.vintage-radio.net/forum/forumdisplay.php?f=36)
-   -   Taylor 45c Valve Tester - a caution -and an appeal for information sharing (https://www.vintage-radio.net/forum/showthread.php?t=8167)

igranic 25th Mar 2006 1:02 am

Taylor 45c Valve Tester - a caution -and an appeal for information sharing
 
3 Attachment(s)
There was I believing that all Taylor 45c valve testers were created equal - that is until I tried to test an ECF80 !

My "Valve Chart for use with the Taylor Valve Tester Model 45C", is an original printed book in its original binding, but it bears no date or version number. For an ECF80 it shows the Selector settings for the pentode section as 1-0-15, and is annotated with a footnote indicating "Model 45c only", which is clearly the type of valve tester in question. However, when attempting a gm test on the pentode section of a known good ECF80, the cathode appears to be open circuit.

Using the pin layout in the Brimar valve manual and carefully working through the settings using the Valve Base Wiring Chart in the Taylor 45c manual shows 1-0 to be correct for switches A and B, but there appeared to be no suitable setting for switch C. Further investigation uncovered another version of the Manual on the excellent website http://www.jogis-roehrenbude.de/Roe-Pruefer.htm, but with different connections shown in the Wiring Chart for switch positions 15 through 17, and another Valve chart with ECF80 settings of 1-0-16. Referring to the Wiring Chart, the 1-0-16 setting appears to be correct, but it does not work with my 45C. So which is the correct Valve Chart and Wiring Chart, and what is the problem with my tester?

With Anode set to 100v, Screen set to 60v, grid set to 15v, and a voltmeter connected to each pin of the B9A socket in turn, I rotated each of the Setting switches through each of the 18 positions and created a new chart based on the results. I deliberately chose these voltages so that it would be immediately obvious which of the valve electrodes the tester expected on each pin. As might be expected, there were a number of discrepancies between the Wiring Charts and the actual results, but only in switch positions 15 through 17.

I have attached this chart along with the two wiring charts I have found.

The obvious conclusion to be drawn from all this is that Taylor produced several versions of the 45c, each capable of testing a slightly different range of valves, but did not differentiate the design variations with model number suffiixes. Presumably, within the Taylor company they used the serial numbers to differentiate versions. Does anyone have any information on this?

If any forum member owns a copy of either the 45c Manual, or Valve Chart, could you please post a scan of the Wiring Chart (with any available version number or publication date), Socket Layout, and Serial Number so that we can compare them against those included here? The corresponding valve tables would also be useful if they are available in electronic form. As they are likeley to be too large to post here, they can be sent to me by PM .

If there is sufficient response, I will post an analysis here along with a chart of later valve types so that we can all benefit from the information. Hopefully, this should enable the more adventurous 45C owners to update the switch wiring of earlier 45Cs to a later, more complete version.

retailer 2nd Apr 2006 5:20 am

Re: Taylor 45c Valve Tester - a caution -and an appeal for information sharing
 
My original 45c valve data book (no date or version number) also shows 1-0-16 for ECF80. A small slip of paper has been inserted which reads 6BL8/ECF80 1-0-15. This setting however does work giving expected results. I have repaired 3 of these and convereted a 45B to 45C specs by replacing the 10 position switches with 18 position switches and hav'nt realised that there may be differences within the same model number until I read your post. Give me a few days and I'll scan and post the circuit and valve chart along with the serial number. I am assuming that my tester is pre 1956 as it also has a hand typed supplement page from Taylor instruments dated Feb 1956. I will also scan and post this.

retailer 2nd Apr 2006 2:36 pm

Re: Taylor 45c Valve Tester - a caution -and an appeal for information sharing
 
1 Attachment(s)
Here's the circuit and valve chart will post the serial num. tomorrow

retailer 2nd Apr 2006 2:48 pm

Re: Taylor 45c Valve Tester - a caution -and an appeal for information sharing
 
1 Attachment(s)
Oops forgot the supplement

igranic 2nd Apr 2006 11:57 pm

Re: Taylor 45c Valve Tester - a caution -and an appeal for information sharing
 
Retailer,

Thank you very much for posting the very helpful valve chart and circuit diagram. The circuit diagram is very useful in that it is dated and refers to other Taylor drawing numbers, and also helps to date the the valve chart, which is very similar to that shown in my dark blue hardback Valve Chart.
Including yours, I have so far collected wiring charts for four variants, but there must be more out there!

Regards
Igranic

retailer 3rd Apr 2006 4:10 am

Re: Taylor 45c Valve Tester - a caution -and an appeal for information sharing
 
My tester has always worked ok so I've never had to refer to the circuit, did'nt realise that it had a date along with a note of circuit changes. Circuit shows germanium diodes for the 'backing off' and 'grid' supplies but mine still has the old selenium rectifiers. Model number 45/28 shown on the circuit ties in with the serial number of my tester 288371.

tvden 4th Apr 2006 10:55 pm

Re: Taylor 45c Valve Tester - a caution -and an appeal for information sharing
 
Hi Retailer many thanks for posting the suplement valve chart, saves me having to work them out regards

largeyo 15th Sep 2006 6:09 pm

Re: Taylor 45c Valve Tester - a caution -and an appeal for information sharing
 
Re Taylor 45B, does anyone know the settings to test a ECC88/6DJ8?, not listed in the manual,is it the same as ECC 81, but 6.3V?, .

retailer 20th Sep 2006 11:31 pm

Re: Taylor 45c Valve Tester - a caution -and an appeal for information sharing
 
Settings I have are 100 60 1.5
triode 1 283
triode 2 590
gm 12.5

Ross_ZL1RDM 11th Apr 2007 1:34 pm

Re: Taylor 45c Valve Tester - a caution -and an appeal for information sharing
 
Hi;- I have a Taylor 45C also with undated original book (also shows 1-0-16 for ECF80) but with hand typed (copied) Alterations, & Additions, date April 1961. A more pressing problem for me is that the lower gm 3mA/V range seems to work OK, and give accurate bogey values for NIB mil valves, but that valves (i.e. KT88) requiring the gm 15 mA/V range caused the tester to hum (traced to loose HT mounting bolts, but still ...) and give erroneous and unrealistically low readings (checked later on a friends calibrated AVO VCM163) - I am wondering if the selenium rectifier is a problem, and whether I need to incorporate (& how much?) series resistance if I replace it with silicon diodes ... I would like to be able to be sure that I am getting decent gm value readings on both ranges! I'd be grateful for any tips or suggestions; also, my scanner has a fault at present, but when I can, I'd be happy to upload the 1961 data if it is of any interest or use, or previously unreferenced? ... ;=})

Thanks & regards;- pleased to discover this forum! Ross~

PS: I also identified and replaced a few resistors that were showing drifted values, and took some pics to aid me, but have not yet drawn them up to the given circuit diagram, which lacks any values. Given the nature of the 45C operation (unsmoothed half-wave DC etc) I am not sure of the importance of the voltage drop across the selenium rectifier for calibration, or whether partial failure on its part could cause erroneous readings as above ... ?

[E&OE;- it's late, here in the antipodes;- some of this is from tired memory!]

igranic 12th Apr 2007 12:10 am

Re: Taylor 45c Valve Tester - a caution -and an appeal for information sharing
 
Ross,

You have a PM.

igranic 24th Apr 2007 9:19 am

Re: Taylor 45c Valve Tester - a caution -and an appeal for information sharing
 
1 Attachment(s)
Thanks go to Neil (scope515) for this addition (s/n 295304) to the libary of Valve Base Wiring Charts.

Attachment 9374

kenneth 24th Apr 2007 3:58 pm

Re: Taylor 45c Valve Tester - a caution -and an appeal for information sharing
 
I too have a Taylor 45C which looks in good condition and I believe has never been abused. However I would like to be able to check that it is up to spec but am unclear as to what the voltages should read when using an Avo8 because of their unsmoothed nature. Also unsure about the wisdom of changing to modern rectifiers and what additional components may be necessary if one chose to do so. Would welcome any advice on the subject or steerage onto an appropriate site.
Thanks

Ken

igranic 24th Apr 2007 4:19 pm

Re: Taylor 45c Valve Tester - a caution -and an appeal for information sharing
 
Ken,

I will take some readings from my 45c using my AVO 8 when I get into the workshop this evening, and post them here for comparison. I will also look at the circuit diagrams and parts lists for the selenium rectifier and semiconductor rectifier variants to check for any other differences.

In the meantime, could you post a copy of your Valve Base Wiring Chart as an attachment, and the serial number of your unit?

igranic 26th Apr 2007 10:34 am

Re: Taylor 45c Valve Tester - a caution -and an appeal for information sharing
 
Ken,

The measured (AVO 8) off-load AC voltages for Anode and Screen voltage settings on the 45c are as follows:
Code:

ANODE
Setting            Measured
  60                    65
  100                  106
  200                  215
  250                  272

 SCREEN
Setting            Measured
  60                    64
  100                  108
  200                  216


Looking at the diagrams, when Taylors changed from selenium/metal oxide to germanium rectifiers
they appear to have made no other significant changes.

HTH
Edward

kenneth 1st May 2007 2:20 pm

Re: Taylor 45c Valve Tester - a caution -and an appeal for information sharing
 
Edward ,
First to explain that due to a domestic accident (I'm temporarily chief cook etc) and also being a parasitic internet user I am sometimes unable to give speedy responses hence the delay in my thanks to you for the info given.
I do not have access to facilities to post pics so am unable to get a copy of the chart to you electronically but am happy to post a photo copy if you would care to let me have an address to send it to.
Don't have the serial no to hand but will send it later. I acquired the unit along with the Valve Chart and Instruction Manual from an ex televsion dealer/repairer and believe he would have bought it from new and therefore the documents will be the ones originally belonging to the equipment. On the bottom right hand corner ot the Valve Chart (brown card cover), in small print, is 1/59 which I have always assumed was the date of printing/publication. The instruction manual cover(greeny/blue) says Taylor Windsor Model 45C Valve Tester but the actual equipment does not include the word Windsor in the printing on the fascia.
Hope this helps.
Ken

kenneth 3rd May 2007 6:11 pm

Re: Taylor 45c Valve Tester - a caution -and an appeal for information sharing
 
Edward,
My Taylor model 45C has serial number T430452. Any help?
Ken

igranic 3rd Jan 2008 1:48 am

Re: Taylor 45c Valve Tester
 
See the follow-on thread for information on the new Taylor 45c & 45b software!

PWH 5th Jan 2008 7:36 pm

Re: Taylor 45c Valve Tester - a caution -and an appeal for information sharing
 
I have a later book dated 8/60, which includes car battery valves and that has the ecf80 as 100 0 16.
Looking at the back of the book there is a note 14 which states Serial No prefix T so maybe the T prefix is how to identify a slightly different model. If it helps I have a diagram dated 16/9/54. Unlike the one in the book of the same date(issue 2) this is issue 7 But it is A2 size.so I can't scan it

igranic 5th Jan 2008 10:52 pm

Re: Taylor 45c Valve Tester - a caution -and an appeal for information sharing
 
I have a feeling that the 'T' prefix to the serial number may refer to the 45C version with a Telefunken socket. A BR9 socket was otherwise used in that position.

One of my (undated) valve charts shows the 'T in a circle' as the annotation symbol for 'T' prefix serial numbers, but I cannot find the symbol used anywhere in the valve table itself. Can anyone verify from their 45c Valve Chart that the 'T in a circle' is used only for valves with Telefunken bases?

Edward


All times are GMT +1. The time now is 3:06 pm.

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