Kolster Brandes 666 Valve radio restoration.

[crackle]

Hi Clive
Yes that is the 600v AC setting for the meter.
It is not essential to do this test but it is a start for you to get familiar with the radio, its layout, components and the use of the meter, it will also show you that there is a nice healthy HT winding giving a voltage of 300 + 300 volts AC. GIVE THIS VOLTAGE A LOT OF RESPECT.

You need to get familiar with working your way around the schematic, finding components that are mentioned and locating them on the schematic and chassis layout drawing.
C19 is in the big cardboard box (mauve), R14 is the large wire-wound resistor on the end of the main component tag board (blue). see coloured layout images.
This is all shown in the service information, what you have to do is identify the connections and follow them around to see where they go to, what other components they connect to and verify what I have identified is correct..
I do not have my KB 666 any more so I can only go from looking at your photos you sent me. Although they are very clear they are only 2 dimensional and I cannot see past items which are in front to connections hidden underneath.
This is where you have to apply yourself to carefully check where the wiring goes. It is up to you to make sure you have identified the correct points. It is also your responsibility to work safely and take all precautions against electric shock. If you are not confident you know what you are doing then ask more questions.
I have done some images to try and get you started, but as I have said you need to be able to identify components from the information in the service manual.
Members here can advise you which components to change and the checks that need to be done but we cant make drawings for every step.
I hope you understand.

chassis photo I have turned it upside down to match the layout drawing.


chassis layout drawing


rectifier socket pins


R14 C19 centre tap junction


If anyone else sees a problem in my advice please speak up.

Mike

[real0real]

Hi Mike
understand layout and thank you for taking the time to show me this ,but i am still little bit confused though exactly which points need to measure with volt meter , if you could show where to prong the black lead from volt meter to a terminal in picture, and where to prong the red lead from volt meter to a terminanal to in picture ,make make me feel bit more confident and cuts down risk of making a mistake

Clive

[crackle]

Hi Clive
I am sorry I dont feel comfortable advising you with this restoration any more at this moment
There are lethal voltages in this radio and you need to have gained enough knowledge and experience to work safely.
Please read through the help notes here to gain some experience. https://www.vintage-radio.com/repair...e-information/


Mike

[Station X]

SET UNPLUGGED.

Use your meter on ohms range to find the common connection of R14 and R7. Reading should be near zero ohms. The OTHER end of R14 is the centre tap of the mains transformer secondary HT winding,

[real0real]

Hi mike
sorry for miss confusion , and thank you for your help upto now would never of got this far without it learnt a lot already
I can now see which is the Large wired wound resistor R14 , and see the R7 ajacent row block /the same side 7th resistor in from R14 as shown on schemitic diagram

with power switched off
using the voltage meter set on 2m hms resistance

i Have checked for resistance am getting a slight reading of 0.147 across the points

Uploaded couple of pictures showing this

[Station X]

0.147 on its own is meaningless. You need to quote units ie ohms, kohms or Mohms. Alternatively specify which meter range you're using.

You're looking for a reading similar to that you get if you touch the meter's leads together on the 2000 ohm range.

[real0real]

Hi

Yesterday when mike mentioned word tap (lol i got confused by when using the word centre tap meaning from transformer to a source point of being able to test ,and not in sence of tap on as a expression )

Fully understand what he was saying now by checking the 2 anodes of rectifier to R14


Have just re-checked the reading from the terminal points with volt meter set at 2000k getting no reading between R7 and R14 terminals checking points

[Station X]

You've lost me completely. Let's try a different approach.

Measure the AC voltage from one end of R14 to each anode of V6 (two readings).

Repeat from the other end of R14 (two readings).

Post the results here.

[Station X]

The anodes of V6 are on pins 1 and 2.

http://www.r-type.org/static/baseb4.htm

[real0real]

Hi Graham
If i am doing this correctly with volt meter i am recieving no voltage reading from anode 1 or 2 when measured to R14 point individualy
have attached picture of 2 anode points i have checked
note , i am doing this with tube/valves not plugged in

(is the transformer suppose to make a slight humming noise when radio plugged in as not hearing one)

[Station X]

Let's take a step back and test the wiring to the mains transformer's primary winding.

UNPLUG THE SET and switch it ON.

Connect you meter on the 2000 ohm range to the live and neutral pins of the mains plug. You should see a fairly low reading, but definitely not open circuit or infinite resistance.

If you don't get the expected reading use your meter to check continuity through the fuse in the plug, the fuse/mains voltage selector and the OFF/ON switch. Use the circuit in post #68 as your guide.

Fix any faults found.

---------

Sometimes OFF/ON switches which have been out of service for a long time need to be worked several times with power applied to remove any tarnishing or W.H.Y from the contacts.

[real0real]

Hi Graham
unpluged , radio set switched on
With volt meter meter on the 2000 ohm range to the live and neutral pins of the mains plug
am getting a reading of 023 hms resistance

[Station X]

Does that reading go to infinite if you turn the set off? It should do.

If all OK, all I can suggest is that you measure the AC voltage between the two anodes of V6. Expect around 600VAC.

[real0real]

Hi Graham
With the set is switched off ,getting no reading at all from volt meter across live and neutral pins of the mains plug

[Station X]

The primary circuit is all OK then.

Does the dial lamp come on?

Check for 4VAC between the two heater pins of V6.

Check for 600VDC between the two anode pins of V6.

[real0real]

Yes the dial lamp does come on when plugged in and switched on

[Station X]

That's a good sign. How about the voltage readings?

[ekjdm14]

Originally Posted by Station X

The primary circuit is all OK then.

Does the dial lamp come on?

Check for 4VAC between the two heater pins of V6.

Check for 600VDC between the two anode pins of V6.

Just a note, I think 600VDC is a typo & you'll be looking for 600VAC

Not taking a cheap shot, as it's correctly noted by yourself elsewhere but just to reconfirm it'll all be AC voltages at this point.

[real0real]

Hi Graham
Have just checked across the pins
possible when this is has been put in the chassis this has been turned around by 90 degrees ,
as across heater pins im getting 600 v
and across the anodes 4v

As to picture that was marked anodes 1 and 2 across these points getting 4v reading on meter
And where marked heaters 600 v, across these pins

[Station X]

Originally Posted by ekjdm14

Just a note, I think 600VDC is a typo & you'll be looking for 600VAC

Not taking a cheap shot, as it's correctly noted by yourself elsewhere but just to reconfirm it'll all be AC voltages at this point.

Yes it should be 600VAC. Nice to see that someone else is following this thread.