Taylor 45A 'Magic eye' tests. - UK Vintage Radio Repair and Restoration Discussion Forum

PWH · 8th Aug 2005, 3:08 pm

I want to know how to test tuning indicators with a valve tester. This may seem silly but I have never used the valve tester till the other day. I put a known good tuning indicator in the valve tester and followed the instructions all seemed well continuity etc but the thing did not glow! I tried several others with the same result.

The 'book' says set it to 100-60-0 isn't that a bit low to get the valve to glow? I don't want to destroy my valve in the tester!!

I am sure there are people out there who have been testing 'magic eyes' for years. Can anyone give a 1-2-3 step to testing say an EM34? thanks..

As this has fallen to page 2, I thought I would refresh the subject just in case any new viewers know the procedure to do a 'glow test' on a magic eye in a Taylor 45A tester.

tvden · 3rd Sep 2005, 8:08 pm

Hi Peter your valve should light on the tester if its working, just be carefull you stick to the given selector settings, you do two tests on these valves,I have a Taylor 45c so my settings may be different, but anyway these eyes are tested in two sections first the normal test on the amplifier section then a test on the shadow section for the later move the anode and screen volts selector from the position given opposite shadow in the valve chart to that opposite test this should cause the valve to change its shadow angle so you use two lots of abc selections, hope this helps perhaps another member may be able to help more

Norman · 13th Sep 2005, 4:12 am

The EM34 have two independent shadows. Put it on the IO1 socket, set 6,3V filament voltage, 3mAV mutual conductance range and, to test the 1st shadow:
- Set ABC to 750
- Set Anode/Screen to 100 60 0 to open angle
- Set Anode/Screen to 100 100 0 to close angle

To test the 2nd:
- Set ABC to 706
- Set Anode/Screen to 100 60 0 to open angle
- Set Anode/Screen to 100 100 0 to close angle

Regards,

8th Aug 2005, 3:08 pm	#1
PWH Heptode Join Date: Mar 2003 Location: Waiheke Island, New Zealand Posts: 503	Taylor 45A 'Magic eye' tests. I want to know how to test tuning indicators with a valve tester. This may seem silly but I have never used the valve tester till the other day. I put a known good tuning indicator in the valve tester and followed the instructions all seemed well continuity etc but the thing did not glow! I tried several others with the same result. The 'book' says set it to 100-60-0 isn't that a bit low to get the valve to glow? I don't want to destroy my valve in the tester!! I am sure there are people out there who have been testing 'magic eyes' for years. Can anyone give a 1-2-3 step to testing say an EM34? thanks.. As this has fallen to page 2, I thought I would refresh the subject just in case any new viewers know the procedure to do a 'glow test' on a magic eye in a Taylor 45A tester. Last edited by Brian R Pateman; 28th May 2007 at 4:07 pm. Reason: Start & refresh posts

3rd Sep 2005, 8:08 pm	#2
tvden Retired Dormant Member Join Date: Oct 2003 Location: Halesworth, Suffolk, UK. Posts: 413	Re: Taylor 45A 'Magic eye' tests. Hi Peter your valve should light on the tester if its working, just be carefull you stick to the given selector settings, you do two tests on these valves,I have a Taylor 45c so my settings may be different, but anyway these eyes are tested in two sections first the normal test on the amplifier section then a test on the shadow section for the later move the anode and screen volts selector from the position given opposite shadow in the valve chart to that opposite test this should cause the valve to change its shadow angle so you use two lots of abc selections, hope this helps perhaps another member may be able to help more

13th Sep 2005, 4:12 am	#3
Norman Retired Dormant Member Join Date: Aug 2005 Location: Porto Alegre/RS/Brazil Posts: 2	Re: Taylor 45A 'Magic eye' tests. The EM34 have two independent shadows. Put it on the IO1 socket, set 6,3V filament voltage, 3mAV mutual conductance range and, to test the 1st shadow: - Set ABC to 750 - Set Anode/Screen to 100 60 0 to open angle - Set Anode/Screen to 100 100 0 to close angle To test the 2nd: - Set ABC to 706 - Set Anode/Screen to 100 60 0 to open angle - Set Anode/Screen to 100 100 0 to close angle Regards,