Dyna Quik 650 - Tube Tester [SOLVED]

[StEeLz]

Hi EEV Community!

I recently acquired a couple of tube testers including this B&K Dyna-Quik 650 but I can't get it to work. I narrowed down the problem to the Full-Wave rectifier tube area.
Looking at the following schematic : http://bee.mif.pg.gda.pl/ciasteczkowypotwor/B&K/BK650%20Cal.pdf I do NOT have 205VDC on Pin 10.
However, this dotted line

is giving me trouble. What is it? What does it mean???

I thought this was a regular link and connected this (no trace of this connection before) and suddenly, I have a voltage on the Pin10, but 450VDC, way too much.

Oscilloscope shows barelly 3VAC whithout connection, and a large sine with DC offset when connected.
What did I miss?

Any suggestion or help would be very welcomed

Cheers!
B.

[singapol]

Please note that stated voltages are measured open with switch at position 1 or unless stated otherwise.
As for 205 Vdc it's measured at position 2.

Are you reading from built-in analog meter or using digital multimeter? Do also note that rectifier diode 83 (gas type) is getting rarer by the day as hifi enthusiasts are also looking for them.You may need to modify to another type of diode (non gas dual diode) if you want to carry on using this BK650.

If you trace from pin 10 it goes to center tap of heater of 83? Another place to look is the meter circuit.
Do also note position 4/5 are connected to cathode of 83. About connecting links..leave them open for time being as it is used for testing grid/heater shorts? Please see service manual as to what changes are done on your 650 based on serial number.

[StEeLz]

singapol, Thanks for the smart analysis!
Pin #10 does indeed center taps with the 83 bulb.
As for the reading, I used variety of devices, but oscilloscope seems to be the most useful for this case.

Interesting fact : When I am connecting the link or grounding that 83 tube pin #3, even with a 10MOhm, voltage instantly jumps!
Any explanation why the Schematics shows a smaller plate for Pin2 than Pin3 as it seems both sides are identical too (Full wave rectifier diode)?

Let me look at the revs as you suggested and I'll post if any interesting!

[StEeLz]

singapol : You are right, my SN included that 10MOhm resistor as per the note in the repair manual. I do have exactly 205VDC now!
Thanks a lot for your help!

[singapol]

Great that means the 83 rectifier is working and putting out the high voltage correctly.
Also there should be a faint purple glow of 83 tube because of the gas.

Normally pin2 which is the plate or anode is drawn shorter than pin 3 cathode.
Rectifier output is taken from cathode or pin3.