My new (used) Fluke 77 Series IV DMM

[LDSisHere]

After a recent power supply incident I decided it was time to relegate my 20+ year old Fluke 21 back to its' original purpose of automotive work. I bought this meter at a pawn shop in 1992 and it has served me well, so much so that I have a great sentimental attachment to it. Recently I have found myself needing a meter with more features. I found what I thought was a good deal on a Fluke 113 but I soon discovered it was not good for much of anything I wanted to do.

Today I thought I would go to a local pawn shop to have a look at selection they had available. I figured if it worked for me before it could work for me again. Although I had only intended to look, I could not pass on this meter. I was able to get it out the door for $39 after taxes and at the time it still had a screen protector on the lens. Granted, it did have a lot of grease stains that made it look bad, but I was able to take care of that with just a little effort. I think I got a good deal, I paid over $60 for my Fluke 21 in 1992, and this meter can do so much more.

I am sure there are some on this forum that would not find this meter suitable for there needs or they are just Fluke haters and I can understand that as I am that way about certain items or brands that others seem to like much to my dismay. I happen to like Flukes (with the the exception of the 113) and I do not see that changing anytime soon. If this meter gives me the same level of service as my old trusty Fluke 21 I think my money was very well spent.

If you have read this far, I hope I have not bored you to death and thanks for taking the time to read this post.

Thanks,
Lloyd

[retiredcaps]

Re: My new (used) Fluke 77 Series IV DMM

I found what I thought was a good deal on a Fluke 113 but I soon discovered it was not good for much of anything I wanted to do.

The Fluke 113 is a very specific multimeter with a certain audience in mind. While it is not really designed for electronics, it is usable for most tasks that we ask of people (i.e. measure DC voltage, resistance, check diode).

I was able to get it out the door for $39 after taxes and at the time it still had a screen protector on the lens.

That is an excellent deal. A new one in Canada sells for $350 CDN + taxes.

Recently, on ebay, there was a big batch of Fluke 77 IVs going for $35, but without the battery door and no test leads. A battery door on ebay goes for about $15. New TL75 test leads sell for $25 CDN.

Granted, it did have a lot of grease stains that made it look bad, but I was able to take care of that with just a little effort.

Some pumice soap like gojo or fast orange will make the holster look like new again.

I am sure there are some on this forum that would not find this meter suitable for there needs or they are just Fluke haters and I can understand that as I am that way about certain items or brands that others seem to like much to my dismay.

The biggest reasons why people dislike Fluke are

1) they are premium priced
2) they lack features compared to some lower cost alternatives
3) outside of the USA, for some reason they are priced up to 2x the USA MSRP price

The 2 "knocks" that some people will point out regarding the Fluke 77 IV are

1) no True RMS
2) no microamp range

Somewhere I wrote, that 99.99% of the time, we never ask people to measure AC or amps for the purposes of this forum (fixing things).

Just some random notes about the 77 IV.

1) Make sure your fuses are good. Sometimes, people sell multimeters as working perfectly, but do not know the fuses are blown. Just put the multimeter in ohms mode and stick the red probe into each amp jack. If the reading is 0L, the fuse is blown.

The fuses in any Fluke multimeter are expensive ($7 to $10 each).

2) Even though it is numbered in the 70 series (your old Fluke 21 is considered a 70 series despite its model number), a good friend took apart a Fluke 170 series multimeter and the 77 IV and he says the board layout is almost identical.

If you have read this far, I hope I have not bored you to death and thanks for taking the time to read this post.

I'm posting at 2:00am in the morning so you know I find these topics interesting.

[Kiriakos GR]

Re: My new (used) Fluke 77 Series IV DMM

Hey retiredcaps, your reply fully covered all the aspects of this topic and there is nothing left to comment.

@LDSisHere
The no True RMS... would keep me away from it.
Especially in our days that the manufacturing cost of the True RMS meters, is not that high.

[LDSisHere]

Re: My new (used) Fluke 77 Series IV DMM

The Fluke 113 is a very specific multimeter with a certain audience in mind. While it is not really designed for electronics, it is usable for most tasks that we ask of people (i.e. measure DC voltage, resistance, check diode).

I figure the 113 would be great for a HVAC person or something along those lines but it is not for me.

That is an excellent deal. A new one in Canada sells for $350 CDN + taxes.

Recently, on ebay, there was a big batch of Fluke 77 IVs going for $35, but without the battery door and no test leads. A battery door on ebay goes for about $15. New TL75 test leads sell for $25 CDN.

Sometimes you can find a great deal on Ebay and sometimes a seller finds a sucker. I had no intentions of buying a meter yesterday but once it was in my hands I did not want to let it go for the price they were asking.

Some pumice soap like gojo or fast orange will make the holster look like new again.

It was a GoJo clone that I used to clean it. It is good at removing sticker residue which the meter also had on it. I am thinking that the dirty appearance is why it was so cheap. I was only concerned with its' functionality and features and it had everything I was looking for so when opportunity knocks it is best to answer.

The 2 "knocks" that some people will point out regarding the Fluke 77 IV are

1) no True RMS
2) no microamp range

1) I suppose getting a true RMS meter would have been nice, it was not going to be a deal breaker for me. I doubt that I would ever have need of it and if I did, I could borrow a meter for that purpose.

2) I have serious doubts that the amp functions will ever be used. For my purposes amp readings are done with a clamp meter.

Just some random notes about the 77 IV.

1) Make sure your fuses are good. Sometimes, people sell multimeters as working perfectly, but do not know the fuses are blown. Just put the multimeter in ohms mode and stick the red probe into each amp jack. If the reading is 0L, the fuse is blown.

The fuses in any Fluke multimeter are expensive ($7 to $10 each).

0.1 ohm on the 10A connector and 1.7 ohm on the 400mA connector.

2) Even though it is numbered in the 70 series (your old Fluke 21 is considered a 70 series despite its model number), a good friend took apart a Fluke 170 series multimeter and the 77 IV and he says the board layout is almost identical.

Mmmmm.. more Fluke modding possibilities maybe? Also I am still confused about the 21 and 70 series correlation. Same everything almost except the number so why did they bother?

Thanks for all this information it was very informative.

[Per Hansson]

Re: My new (used) Fluke 77 Series IV DMM

Nice thread, may I ask what it is you dislike so much about the Fluke 113?
I own one myself and have recommended it on this forum.

Sure the "Auto" functions can be a bit useless and really cause more problems than it helps the end user but it can be put into manual mode aswell...

And it does future "Min/Max" and also "Hold" functionality which I find very useful...
The reason I choose this meter was the price and to complement my Bob Parker ESR meter K-7214 with it's capacitance meter test mode...

[smason]

Re: My new (used) Fluke 77 Series IV DMM

Nice find! I saw a Fluke 77 (original) in a pawn shop last year for $200.00!!
I laughed. I paid less than that for mine back in '88

[retiredcaps]

Re: My new (used) Fluke 77 Series IV DMM

And it does future "Min/Max" and also "Hold" functionality which I find very useful...

The hold functionality on the 110 series requires you to press the hold button to freeze the reading implying you need a 3rd hand sometimes.

[retiredcaps]

Re: My new (used) Fluke 77 Series IV DMM

1) I suppose getting a true RMS meter would have been nice, it was not going to be a deal breaker for me. I doubt that I would ever have need of it and if I did, I could borrow a meter for that purpose.

Since your Fluke 21 didn't have it for the last 20 years, you probably didn't need True RMS.

2) I have serious doubts that the amp functions will ever be used. For my purposes amp readings are done with a clamp meter.

The only I time I needed to measure current was checking my car for a parasitic battery drain. It would have been nice to have a DC clamp meter though.

0.1 ohm on the 10A connector and 1.7 ohm on the 400mA connector.

Those fuses are good.

Also I am still confused about the 21 and 70 series correlation. Same everything almost except the number so why did they bother?

I can only speculate that the 70 series was grey and maybe someone in marketing thought yellow would sell better?

[retiredcaps]

Re: My new (used) Fluke 77 Series IV DMM

I didn't notice it earlier in your photo, but the yellow silkscreening seems to have faded or been rubbed off (from a cleaner) for all the secondary functions?

[LDSisHere]

Re: My new (used) Fluke 77 Series IV DMM

Nice thread, may I ask what it is you dislike so much about the Fluke 113?
I own one myself and have recommended it on this forum.

Like you I bought mine mostly for the capacitance testing and also for it too hopefully replace my Fluke 21 on the bench. My first problem was with the meter is that it is a pain to force it to do what you want due to the lack of options on the rotary switch. My second issue was when I was checking voltage on my breadboard that was being powered by a LM350 voltage regulator. When I tried to check the voltage with the leads in the proper orientation (+ to + and - to -) it gave me so strange readings (I do not recall the details.) but when I reversed the leads it would give me the proper voltage setting but with a negative sign as would be expected. Since I could never get it to give the correct reading with the leads in the proper orientation, I felt that I could not trust the readings it gave me. This was why I do not like it, so I decided I was better off getting a different meter.

I didn't notice it earlier in your photo, but the yellow silkscreening seems to have faded or been rubbed off (from a cleaner) for all the secondary functions?

I noticed that this morning myself so I suppose I will have to mark it myself. I do not know if it was the hand cleaner or the 90% rubbing alcohol that I used to clean off the hand cleaner but they are gone. I would have rather not have had this happen but it does not affect its' operation and I can always mark it myself so I am not going to loose any sleep over it.

[PeteS in CA]

Re: My new (used) Fluke 77 Series IV DMM

Somewhere I wrote, that 99.99% of the time, we never ask people to measure AC or amps for the purposes of this forum (fixing things).

In ~35 years working in electronics I can think of just one place I worked where I had to use a DMM (Fluke 83s and 85s, FWIW) to measure current, and it was for currents in the Amps range, not uAmps. A current probe and 'scope? Lots of times. As for true RMS, most of the time - and it also is very infrequent - I'm measuring 60Hz or 400Hz AC, mainly to see if it's there at all, and occasionally to adjust a variac.

I like the better precision and resolution of high-end hand-held DMMs (and sometimes actually need it), but much of the time 1%-2% accuracy is perfectly adequate. Now, if you're trying to set a 7.1 KV output voltage to +/- 2V or 3V, you do need a higher-end hand-held DMM (and a high voltage probe calibrated together with the DMM).

[Logistics]

Re: My new (used) Fluke 77 Series IV DMM

Paid about $170 for mine, new and I thought that was a smokin' deal at the time. Good job, man.

[randtek]

Re: My new (used) Fluke 77 Series IV DMM

My first digital meter was a Fluke 77. It lasted me 20 years of daily use/abuse in a high production shop environment. With reliability like that, replacing it with the Fluke 179 was a no-brainer. And Fluke gave me a huge discount for trading in my 20+ year old (and finally failed) 77. For $39.00, I would be watching for the police to arrive, because you stole that meter!

[LDSisHere]

Re: My new (used) Fluke 77 Series IV DMM

Thanks for all the feedback everyone. I felt at the time I would be stupid to walk away from this meter but from all the feedback I now know I the the smart thing and I got a good deal.

[retiredcaps]

Re: My new (used) Fluke 77 Series IV DMM

For fun, hookup up Fluke 21 and 77 IV to the same ATX power supply and measure the 5V and 12V DC rails using the molex connectors. Try the same for measuring an AA battery so we can see it down to the mV resolution.

It would be interesting to see if the Fluke 21 has kept its calibration over 20 years.

[Kiriakos GR]

Re: My new (used) Fluke 77 Series IV DMM

It would be interesting to see if the Fluke 21 has kept its calibration over 20 years.

I had buy three 80xx bench top Fluke meters on ebay at 2010,
which I got and retest or repair.
The one of them was offered as calibrated.
The point is that all of them was almost spot-on at DC, but the AC was another story.
Fluke advices on those models AC test voltages at 200Hz, so to perform the adjustment.
With out my high quality function generator I would be unable to do this fine adjustment to them.

Edit:
Here is a picture before any adjustment at DC.

[LDSisHere]

Re: My new (used) Fluke 77 Series IV DMM

For fun, hookup up Fluke 21 and 77 IV to the same ATX power supply and measure the 5V and 12V DC rails using the molex connectors. Try the same for measuring an AA battery so we can see it down to the mV resolution.

It would be interesting to see if the Fluke 21 has kept its calibration over 20 years.

I have to admit that I thought the two would be close but... it was not too be. I will now have to carry one or both to work with me and compare them to the calibrated Fluke 179 to see which one is off. I suspect and hope it is my 21 as it is close enough for automotive work anyway.

[retiredcaps]

Re: My new (used) Fluke 77 Series IV DMM

I have to admit that I thought the two would be close but... it was not too be.

If the Fluke 21 is off, you can adjust it quite easily. There is only 1 pot (DC V) to turn and it is to the left of that 0 ohm resistor. There is no pot for AC V.

If the Fluke 77 IV is off, you can't adjust it at home. The 77 IV like the 179 is closed case calibration.

[retiredcaps]

Re: My new (used) Fluke 77 Series IV DMM

Use a 3.000V DC source for calibration. I find that the green pin on some ATX power supplies is close to 3.000V. Have the other calibrated meter plugged in at the same time so both read the same value.

See my example of calibrating a Fluke 77 II

http://www.eevblog.com/forum/general...254/#msg152254

[retiredcaps]

Re: My new (used) Fluke 77 Series IV DMM

I have purchased 3 used 20+ year old Fluke 70 series style multimeters and all have been within spec (0.3% + 1 digit) in the DCV range. The 77 II that I cleaned up with was the "worst" at 4mV off, but still within specifications.

If your Fluke 21 is the one that is off, that is the worst drift I have personally seen in an older Fluke.