Lafayette CR Analyzer.

[Rob Flinn]

I've been looking around for a cap analyser for sometime mainly looking at heathkit but not been able to find anything that wasn't expensive and needing a complete rebuild. Anyhow I just got this Lafayette TE 46 CR Analyzer. I can't believe the condition for the age. It's like it is brand new in the original box the leather carrying handle shows no sins of wear and internally it is spotless. I specifically wanted one that would do high voltage leakage tests. It has the added function of being able to determine transformer ratios..

 

[NOON]

I've got one that wasn't in anywhere near as good condition. I gave it a clean and replaced a bunch of leaky and out of spec components and it works well now. Main issue is that the cap testing voltages aren't regulated and are significantly higher than marked at standard wall voltages here in Australia. I run it off a variac for predictability. Even in great physical condition I'd be replacing electrolytics and checking old resistors for drift.

 

[Rob Flinn]

I've got one that wasn't in anywhere near as good condition. I gave it a clean and replaced a bunch of leaky and out of spec components and it works well now. Main issue is that the cap testing voltages aren't regulated and are significantly higher than marked at standard wall voltages here in Australia. I run it off a variac for predictability. Even in great physical condition I'd be replacing electrolytics and checking old resistors for drift.

A few questions.

Did you mod yours to have a safety Earth ?

Is it possible you could take a pic of the connections to the mains transformer. I'm not sure if mine is wired for 117v or 230v & am a bit concerned to plug it in because it has a U.S style mains plug ?

I tested the caps with an ESR meter & they check ok. Although I bought the Lafayette to check leakage on H.V caps so can't really test them how I'd liked. I plan on testing all the resistors etc anyway.

 

[NOON]

Yes, I added a safety earth and fusing to mine to bring it closer to modern safety standards. It's packed away at the moment so can't take a photo, but you should be able to determine the mains voltage windings by checking the resistance, 240v will be the highest taps.

 

[rock soderstrom]

Anyhow I just got this Lafayette TE 46 CR Analyzer.

Beautiful! I really like the design and the condition is really flawless. What do you pay on average for a device like this?

 

[rock soderstrom]

I specifically wanted one that would do high voltage leakage tests. It has the added function of being able to determine transformer ratios..

These are functions that I could also use very well, unfortunately they are not so common on similar devices that my quick web search found.

 

[NOON]

The cap tester from Mr Carlsons lab looks pretty good, yet to make one myself.

 

[Rob Flinn]

These are functions that I could also use very well, unfortunately they are not so common on similar devices that my quick web search found.

That's why I was looking at the heathkit LCR bridges. It's easy to get a basic capacitance bridge, but in todays world quite a basic digital meter will give you the capacitance value, it's the leakage functions at working voltage etc that are useful.

 

[rock soderstrom]

it's the leakage functions at working voltage etc that are useful.

Definitely, the normal component testers show important things but they say nothing about whether, for example, your NOS MP capacitor for your vintage mic will hold tight under real conditions. Without such an analyzer, this can be an expensive experiment.

 

[Rob Flinn]

The cap tester from Mr Carlsons lab looks pretty good, yet to make one myself.

Briefly looking at his design will it test a 400v cap at 400v ? It doesn't look like it does, but I could easily be wrong....

 

[NOON]

Briefly looking at his design will it test a 400v cap at 400v ? It doesn't look like it does, but I could easily be wrong....

It doesn't, but it's designed to be super sensitive to low levels of leakage at lower voltages.

 

[Rob Flinn]

It doesn't, but it's designed to be super sensitive to low levels of leakage at lower voltages.

I specifically bought this analyser for it's ability to work at high voltages, therefore the Carlson analyser would not be much use to me. However, I could see it could be useful if one only works at safe voltages.

 

[Hubbub]

I have an old transistor curve tracer that can be operated at DC, with up to 1500 V across the DUT. With sensitivity to uA it would even let you look at the leakage noise level.