Get a Fluke DMM

[ThSpeakerDude88]

forget a fluke, for right now anyways. While I'm sure evryone here has one , there are a lot of people that cannot afford one. A cheap dmm will not do you good service, however one in the $30-$50 range from radioshack or sears will. I have been using my micronta for some time now, along side a nice sears one, and they are both very close to a fluke dmm. Yes you should get a fluke sometime down the road, but for now please get a cheap dmm from the shack or sears. Better to waste a little money on one project than a lot if it doesn't work. Sometimes people get so used to spending a lot of money on a project they dont realize that others might not have quite so much in reserve. I have built several guitar amps am working on a couple of hi-fi amps right now, all have cost me between $130-$500, so even I sometimes jump to conclusions about "oh thats a cheap part you should be able to afford it" When in reality it is a $55 hammond transformer. True it is cheap compared to a luhndahl or mercury, but not cheap to someone with a very limited budjet.

Also, you may try www.tubedepot.com for parts. They dont have as good of a selection as tubesandmore, but they are located in tennesee and shipping will be less and take less time. I use both them and antique electric supply and they both have great service and have always been courtious.

Best of luck! That is a nice amp you have there- any chance you can look up the date codes on the tubes? ( should be some small numbers seperated with a dash).

Just my 2 cents- TSD88~

[anatech]

Hi ThSpeakerDude88,
A used, working Fluke is far better than what you are using now. I'd rather see people using a Fluke 87 from Ebay - untested before any Radio Shack or Sears model.

I employed guys as technicians and had a few that used those type that you are using. Utter trash. Later, working as a calibration technician, I was able to see just how bad those were compared to a Fluke.

So much so that I can comfortably say

Buy the Fluke !!!!!! No other meters exist that don't lie, save the new Agilent.

So you are doing yourself a disfavour unless you are not taking careful measurements. Your meter is a millstone around your neck. They are fine as secondary meters, but not as your best, or primary meter.

-Chris

[ThSpeakerDude88]

I didnt say that what I had was better than fluke... I said that they are perfectly fine and consistant enough to make general measurments when trying to get something as forgiving as a tube amplifier working. When I am working in more criticle areas I use my fluke.

I merely sugguested that he get an above-average cheap meter that he can afford right now, that he does not have to order online and pay shipping for, and wait for, rather one he can get in town preferably.


DeadSpeaker: That would make sence. It is a pretty good guess that the tubes are from 1965.

What brand are they? Try looking at the output tubes. Quite a few 6L6's bring decent money used depending on brand/plate color and type. It is nice to know just in case they are worth something, then you should be even more careful with them so as not to harm them.

[isaacc7]

Originally posted by anatech
Hi ThSpeakerDude88,
A used, working Fluke is far better than what you are using now. I'd rather see people using a Fluke 87 from Ebay - untested before any Radio Shack or Sears model.

I employed guys as technicians and had a few that used those type that you are using. Utter trash. Later, working as a calibration technician, I was able to see just how bad those were compared to a Fluke.

So much so that I can comfortably say

Buy the Fluke !!!!!! No other meters exist that don't lie, save the new Agilent.

So you are doing yourself a disfavour unless you are not taking careful measurements. Your meter is a millstone around your neck. They are fine as secondary meters, but not as your best, or primary meter.

-Chris

Hmm, Tubelab has a much different opinion than you and I have to say that when dealing with noobs like myself (and the OP) I think his advice is sound. It would suck to blow up your fancy fluke because you forgot to switch it to the appropriate mode.


Tubelab's advice is to use multiple cheap meters in order to maximize safety. I'm going with his technique when I start building even though I do own a Fluke...

Isaac

[kevinkr]

Originally posted by isaacc7


Hmm, Tubelab has a much different opinion than you and I have to say that when dealing with noobs like myself (and the OP) I think his advice is sound. It would suck to blow up your fancy fluke because you forgot to switch it to the appropriate mode.


Tubelab's advice is to use multiple cheap meters in order to maximize safety. I'm going with his technique when I start building even though I do own a Fluke...

Isaac

That's the nice thing about Fluke dvms, they won't blow up if you select the wrong mode unlike most cheap meters.. The only thing that happens is on the current ranges you can blow one of the internal fuses. Voltage and resistance ranges are indestructible provided you stay at or below the meter's maximum rated voltage. IMO this is one of the things that make it a particularly good choice for a newbie, and I can tell you I have destroyed enough cheap meters to pay for several Flukes, and have never destroyed any Fluke meter. I'm totally with Chris on this one, not like fixing this thing instantly is THAT urgent.

[isaacc7]

Did not realize that Flukes were not in as much risk for being blown up, but did you read Tubelab's page? I like the idea of getting all of the readings at once and not poking around in a live circuit. If they are accurate enough, I still like his approach though I won't worry about my Fluke as much now:-)

Isaac

[poynton]

continued discussion about Fluke meters is not going to get the amp fixed !!!

[anatech]

Hi poynton,

continued discussion about Fluke meters is not going to get the amp fixed !!!

I completely agree with you. However, the fact that the meter DeadSpeaker is using is defective and not reliable came out. He is unable to test components with any confidence right now. Therefore the topic of reliable DVMs came up.

So, the facts are.
1. You need one reliable meter to gauge other less expensive ones against.
2. Fighting with test instruments is no way to fix anything. They can mislead you.
3. More expensive meters are far more durable and "idiot proof" than cheap meters.
4. It's a good idea to have some cheap meters around once you know how they behave (against a standard).

Hi Isaac,
Fluke meters are protected much better than most. It is still possible to blast them to bits. They even bounce better if you leave them in the yellow plastic casing. Best of all, they hold their calibration and are accurate to higher frequencies. Another reason right there to buy a Fluke. Beware Extech meters. They do not hold their cal and are damaged easily.

Tubelab has a much different opinion than you and I have to say that when dealing with noobs like myself

All I have to say about that is run a checklist when you are measuring. I agree that cheapo meters set properly for a number of measurements is a very good plan, but you still must start with at least one accurate meter. Go ahead and use some cheaper ones too. I do, so I agree with tubelab in a way.

-Chris

[nhuwar]

It doesn't matter what kind of meter you buy if you dont get it calibrated you still don't know if your numbers are right.

I have bought many radio shack meters and have them calibrated and they dont drift at all.

Nor do the flukes but I have seen keithley's drift.

Nick

[anatech]

Hi Nick,

It doesn't matter what kind of meter you buy if you dont get it calibrated you still don't know if your numbers are right.

After working in a calibration lab and seeing hundreds of meters, I have a feel for new and old meters.

Flukes were 99.9% in calibration out of the box (we sold them with a calibration option). Years later these same meters were still within tolerance.

Most other meters were iffy on cal new. Some were out and could not be optimized due to their attenuator. Fluke uses a temperature corrected thick film assembly, most others go with separate resistors. Fluke's attenuator is corrected for higher frequencies too.

I have bought many radio shack meters and have them calibrated and they dont drift at all.

That's about opposite my experience unless they have Fluke making them now (doubt it), Escort may not be too bad. They may not compare to Fluke though.

Nor do the flukes but I have seen keithley's drift.

Wow! Keithley's drifting? I've only seen that when they are subjected to high voltage (above ratings). Keep in mind the expected temperature range from the calibration temperature.

I accept that you should have new meters calibrated, however this adds about $85 to $160 to the price for a traceable cert (the only one worth anything). Since most of us can not afford that, wouldn't it be nice to have confidence that your new meter is in cal? Mine was in cal when I bought it, and still in tolerance when it was certified again 10 years later (HP 34401A). Buy quality.

-Chris