I have been trying to download

Valve Chart :45C, 45A, 45B, 46A, 47A.pdf

from this very useful site without luck.

Has anyone else had problems with this site?

I own one of these testers and have been trying to get it going after some years on the shelf, and some repairs to the circuit selector switches, in two of which plastic parts collapsed.

It downloaded okay for me. It's a 31 Mb file. If you unhide your email address (via Control Panel) I'll see if I can email it to you.

Thanks GTC, address unhidden.

I'm trying to send it via two ways -- either or both of which may be successful.

It's a large file and will take some time to send. I hope your email account has room for 31 Mb (possibly x 2).

Update: Okay, from my end it seems that only the YouSendIt method was successful, so you should be able to download that copy.

Thanks GTC, 82 page pdf arrived safely.

Evidently there are various versions of the 45C tester with amendments and corrections in the manuals provided.

Wanted to see if the Chant document agrees with the manuals that I have which did not come with the tester, and might explain difficulties I have had testing some valves years ago.

Also, the plastic parts that collapsed carry the stop for the switch, and this stop broken off in both cases. This means that it is difficult to know with surety which numbered position the switch is at, as the switch is not positively located with a flat for example, in the chassis. Hopefully I can work something out with these new charts by looking at the actual wiring for a particular position.

Despite the valuable help received, I am still having trouble getting Taylor 45C valve tester running. Using the circuit provided I was able to check that switch positions are indicating on the front panel correctly by comparing switch slider positions to switch wiring at various connections.

The major issue now is that during mutual conductance testing AC appears on the test meter as needle vibrations. I have tracked this to AC appearing on one of the resistors of this test circuit, which overheats.

This leads me to think that there is still a problem with switch position, or some undetected short.

I have replaced the selenium rectifiers with 1amp 400 to 600V silicon devices, but a bridge rectifier with 6VAC across it is only putting out 4.8VDC. This makes me think it is cooked because it is under rated, or by the current pulled by the overheating resistor. The selenium bridge rectifier replaced is shown as 5D133 on the parts list and has 4D133 marked on it.

Does anyone recognise these seleniumdevices? Google reveals zilch.

My tester has one extra resistor not shown in Kevin Chant's circuit, though given its value and where it is in the circuit, I don't think it is contributing to the above troubles. Another difference is that a resistor shown in the table as 1200ohm, is 7200ohm in the tester.

Can't offer specific help, but perhaps you may get more info from a UK site, e.g.

http://www.vintage-radio.net/forum/showthread.php?t=64907.

Thanks for that GTC - a couple of good leads including a fellow who tracked AC on the test meter during Mutual Conductance testing to one of the rotary switches not changing completely from the previous Cathode Leakage test position where 60VAC is applied to the valve elements.

I suspect that my case is similar considering three repaired switches. Might have to bite the bullet and replace all rotary switches. Not a happy thought - the wiring is a rats nest with closely spaced switches and much use of fragile single conductor wiring.

My tester has Muswellbrook marked on it in yellow paint, so probably came from a Tech College or some part of the old Electricity Commission or System Control. Its serial is 330119.

Unfortunately the UK web site does not have any circuits for a number anywhere near this (most are T prefix for an extra Telefunken valve base), and none with my extra resistor. So mine is probably an early model sent to the Colonies.

Unfortunately the UK web site does not have any circuits for a number anywhere near this (most are T prefix for an extra Telefunken valve base), and none with my extra resistor. So mine is probably an early model sent to the Colonies.

Could be worth making a post there. You never know who might pop up with info.

Managed to get my tester working again. In case anyone else has one of these, the main fault was a short between tabs of adjacent rotary switches which resulted from manipulations during repairs to the switches mentioned above- hard to spot as they are very adjacent.

The plastic parts were repaired by super-gluing, and then binding tightly with cotton thread, and applying super glue to the thread.

Other issues were aged selenium rectifiers which had to be replaced with silicon devices. A point to note here is that mutual conductance testing is performed by applying AC, full wave rectified and half wave rectified AC to the various valve elements (this is explained in the instruction book). The phasing of the AC varies depending on the element. So the orientation of the transformer secondary wires going to the rectifiers is important. Easy to overlook as normally when wiring a rectifier this is not a concern.

Some resistors had gone high and a low resistance cap (C1 0.1microF). This cap is close to 3-6watt wire wound resistors and appears to have suffered from the heat. This cap is specified as metal encapsulated. Not having one in the junk box, replaced it with a plastic encapsulated mounted away from the heat. Seems to be OK.

Thanks for the help provided.

Managed to get my tester working again.

Good to hear! Well done.