[Stevie342000]

I finally bit the bullet and bought one of these yesterday (it has not arrived yet) but I thought I would ask some questions on how I go about repairing the item (my assumption being that the old paper in oil capacitors will be shot).

I have lots of pieces of equipment that I need to repair and I thought this would be a useful piece of kit to have to test all those old capacitors. I know I'm making work for myself when I should taken it as a given and just replace them all.

Having searched the web and this forum I have all the information I need including the manual for me to repair the item - it was the first thing I did before I purchased it.

1. I assume I should be looking at replacing C1 - C9, C11 - C16 & C22, the others are the precision standard capacitors.

2. Should I be looking at any of the resistors? My thinking is the 20% tolerance is not as precise and may have drifted, will check the high values to make sure they are in spec - I have a digital LCR which I can use or an Avo Model 8 (note to self must look to see if Maplin have the BLR battery).

3. How do I clean the switches and with what? I'm not wishing to dismantle them.

4. Do I need to calibrate the instrument once I have changed the capacitors (and if so not sure how the instructions are not particularly clear)?

5. The reason I am not looking at most of the resistors is that they are precision mostly 1% or 2%, they will of course have a lifetime as well but they should not have drifted much, is this a wrong assumption? Again I am assuming that they will be pink bodied and be made by Paignton.

Thanks, I hopefully have a number of winters work to keep me going once this has been fixed.

Ah yes why do I not just use the digital LCR, well this instrument in my mind is far more useful for matching components. I assume if you attach a known tolerance resistor or capacitor this then becomes the standard against which you are measuring which means you can get really closely matched or tolerance values.

Oh yes of course it is me being a bit of completest freak and wanting to use period equipment on vintage restorations. Apart from which this is stunning to look at much like my BBC Test Equipment - TS10 & ATM 1 (both of which will be checked over with this piece of test kit before being put into service.

In addition I have a Scopex 4D/25 dual beam oscilloscope - but no idea of that works or not - it has been discussed here (I will need to go read that thread). I have the bits for lamp limiter as well as instructions.

Other than that I do not think there is anything I have missed, Oh yes the Heathkit AG-9U, needs repair as well. Then there are all the reel to reel tape recorders and other bits I want to build from new - including a valve stereo FM Decoder for the Quad FM1 and the Jason FMT-3 (Wireless World Article 1962).

The only thing I do not have is a frequency counter but I thinking of going modernist with that and getting a new one from China, a valve one would be big and probably expensive and solid state will contain unobtanium thus I am taking the supply source with the least resistance plus they are cheap, any thoughts or suggestions?

I have some experience in building valve equipment and about 20 years back I built a hybrid phono amplifier (an ETI project) which worked first time and looked like a rats nest as it was not in a case and it worked perfectly first time I powered it up (that is another one of my projects to revisit too). My knowledge and understanding is what has increased in that time frame and now it is time to tick items that I want to repair or build off my bucket list.

7. The lettering around the switches and dials looks like it needs to be filled in again - what should I use to do that? Correction that was the other earlier model I was looking at not this one - the front panel lettering is perfect.
8. What should I used to clean the outside so I can determine if that lettering is white or red, assuming they did not use any other colours on the front panel?

My plan as a starter for 10 is to build the lamp limiter, check the Universal Measuring Bridge over visually and then fire it up to determine if there any issues before replacing the capacitors, I do think replacing all of them except the standards is over kill but they are all going to be at least 50 years old and they will be near or at their end of life.

Oh yes I have variac as well 5 amp which I am going to include in the lamp limiter, it should power most of the equipment that I have. However I feel this Avo Universal Measuring Bridge is the linchpin as at least I can test all the equipment I have and replace what needs replacing to bring it all back into working order.

I have spent the last 10 years plus hoarding tape machines, Brenell (it is my opinion that the Brenell tape link is the same as the Jason tape link and appears about the time Jason goes out of business and Brenell bought the rights to produce it)and Jason Tape links (the article to build one of those from Kit form is in one of the tape recorder magazines on American Broadcast history), amplifiers and so forth building the system I want from new to bring this all back into working order.

I have for now called a holt to purchasing any more items the Brenell STB - 2 I got the other week was the last piece in the jigsaw, other than full studio tape machines by EMI or Leevers-Rich and honestly I do not really need those and it would be more overkill. The end!!!!