Test Equipment Anonymous (TEA) group therapy thread

[factory]

More pictures of the Danameter

[EggertEnjoyer123]

Well I’m back again after quite a while.

I finally fixed that $5 multimeter from a year ago. It didn’t work at DC, but AC and Ohms worked. Looking at the DC path, I quickly found a 2.7 ohm resistor which failed open. Interestingly there were no burn marks on it.

I have six bench multimeters now.

I also figured out why my HP LCR meter didn’t work with the Amazon 4 wire Kelvin probes. It turned out that all of the BNC grounds were floating and needed to be shorted together near the DUT for the meter to work properly.

[factory]

It's not a common failure, but I have seen open film resistors with no burn marks, a few times times over the years.

David

[TomKatt]

It's not a common failure, but I have seen open film resistors with no burn marks, a few times times over the years.

David

OT - just noticed your avatar…. Looks a lot like my HP180A scope  . Mine is still running strong - the only work done was replacing the power supply filter caps, which turned out to be fine after all.  In hindsight I should have left it alone, but I guess no harm done other than a waste of time and money.  I was younger and less experienced when I bought it many, many years ago.

[m k]

Dana Danameter DMM

What is that small vertical PCB, some high voltage AC pulled away from disturbing?

[factory]

Dana Danameter DMM

What is that small vertical PCB, some high voltage AC pulled away from disturbing?

It's U3 on the circuit diagram, it's the 'attenuator module' according to the parts list, the circuit description is a bit lacking in this manual and the switching is not labelled on the circuit diagram.

The modules at the other side are mostly resistor networks, except one that is a mix of capacitors & resistors, I've no idea why one has a bunch of bodge resistors on the back. 

When I've got some free time I intend to scan the manual.

David

[factory]

It's not a common failure, but I have seen open film resistors with no burn marks, a few times times over the years.

David

OT - just noticed your avatar…. Looks a lot like my HP180A scope  . Mine is still running strong - the only work done was replacing the power supply filter caps, which turned out to be fine after all.  In hindsight I should have left it alone, but I guess no harm done other than a waste of time and money.  I was younger and less experienced when I bought it many, many years ago.

It's the 180A rack mount version, from this post; https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/msg3619001/#msg3619001
An early one built in the South Queensferry factory in Scotland, avatar pic is a cropped/rotated picture from the repair of the trigger fault in the 1801A module, which turned out to be a 4-092 transistor that had gone open between base & emitter.
All the PSU caps are still original, but some of the plastic transistors are not. A pair of wet tants in the 1801A were replaced, due to leaking their contents, as was a hermetic sealed tant that shorted.

David

[TomKatt]

HP marketing made a big deal about the 180A being completely solid state - but I note some of the voltage regulators are specialized neon bulbs that can fail over time because apparently they require some radioactive decay to properly trigger, which decays over time.  Those and a few other components like tunnel diodes are apparently difficult to get these days.

But so far mine keeps chugging along - and it’s been a very reliable piece of kit and I’m very fond of it.  I once saw a 4 channel vertical plugin for this series on eBay, but missed the opportunity…. I wonder how well that would have worked considering the crt is a single gun and additional channels are created by chop/alt logic.  Still, it would have been cool to have.  Even though before digital became prevalent, I did just fine with 2 channels.

CuriousMarc on YouTube has a similar scope as well - it can be seen in a few of his Apollo 11 communication series.

[Robert763]

So I went to the Dunstable Downs (Luton UK) Radio Rally today. Mostly getting rid of stuff but I did make a couple of aquisitions. A HP1661A logic analyser (96 channels). It does not complete POST, video goes out of sync. Probably a PSU issue. It did come with a good collection of leads, pods, clips and adaptors. And I have a 1662A (64 channels) so hopefully I can make a working 96 ch out of the pair. No brainer at £15.
Only other significant purchase was Collins 618T-3 and 714E. For non Collins fans that's an aircraft HF transceiver and control head. Covers 2-30MHz with 400W PEP output.

Robert.

[factory]

Trouble is if I buy something for parts, I can often end up fixing both, it'll be interesting to see if you manage to fix it.

David

[factory]

HP marketing made a big deal about the 180A being completely solid state - but I note some of the voltage regulators are specialized neon bulbs that can fail over time because apparently they require some radioactive decay to properly trigger, which decays over time.  Those and a few other components like tunnel diodes are apparently difficult to get these days.

But so far mine keeps chugging along - and it’s been a very reliable piece of kit and I’m very fond of it.  I once saw a 4 channel vertical plugin for this series on eBay, but missed the opportunity…. I wonder how well that would have worked considering the crt is a single gun and additional channels are created by chop/alt logic.  Still, it would have been cool to have.  Even though before digital became prevalent, I did just fine with 2 channels.

CuriousMarc on YouTube has a similar scope as well - it can be seen in a few of his Apollo 11 communication series.

The 180A is also fanless, we know how much some on here hate fan noise.

The voltage reference tubes can be replaced by a transistor, resistor & reference Zener based circuit, such as the one used by Philips, note the resistor values would need changing for the 82V ref tube.
Later versions of the 140/1 & 18x series used a redesigned circuit, with a 9V TC Zener.
I've had some failures of metal film resistors, including those used in the PSU voltage dividers for the voltage setting and those used in the horizontal amplifier.

I've yet to find a scope with a tunnel diode fault, the plastic bead ones used in the HP counters seem to be more of a problem, I don't know if that is an age related failure, or a previous user/owner damaging them.

The four channel plug-in, there are two for the 180 series, the first is the 1804A (50MHz) and the second is the 100MHz 1809A, note there are others that are not compatible (those starting 183x are for the 183 series).

David

[factory]

A while ago I acquired a rather crusty HP 3480B locally, I've posted some picture of this on here previously. HP 3480B/3481A voltmeter, [2], [3]



As can be seen in the links, this was in quite a poor state, with corrosion, only three of the displays work, measurements were quite a bit off spec. Last weekend I started by stripping it down to clean & polish the frame sides and cleaned the rest of the case parts, with the exception of the display filter (the manual notes the metal finish on the inside, can end up with difficult to remove fingerprint marks if handled).

It's partially reassembled at the moment, with the minimum of boards refitted, first things to check as always is the PSU, the capacitors where checked with the Peak ESR, no problems found here.
Then measuring voltages of the PSU outputs, they were all wrong at first, turns out the plug-in is required to be fitted, as the PSU measurements are referenced to the black low terminal. 
All the voltages were within spec, except for the +5V rail, which was 4.7V with some excess ripple, I noted the 5.6V overvoltage stud mount Zener was getting a bit hot, this was a clue.

But to in order to confirm if the problem was an overvoltage from the PSU, or a faulty Zener I took measurements of the rest of the +5V circuit.



After not finding anything else that seemed wrong, I removed the Zener and checked it with the Peak DCA, yes you've guessed it, it's no longer a 5.6V device, it now identifies as a 4.5V Zener. I'm going to see if I have something suitable in storage.







Other problems, I'm going to need to find a another display for it, as it's only a 3.5 digit DVM at the moment, the bulb has failed with the glass cracking, due to rusted pins, a common problem, it will take some time to find one that is known to work & doesn't cost a kings ransom, there are a lot of duds on ePay (I've been caught out before with these  ). And finally some of the lamps for the symbols are blown.

The 3841A is quite an uncommon choice of plug-in, there are currently no manuals on the web that I know of, there is however a Microfiche in a collection that one of the HP groups.io guys acquired. At the moment I'm going to build the test adaptor described in the 3480A/B manual, this allows testing of the mainframe without the plug-in, as I don't know which is at fault.

David

[shakalnokturn]

Any idea who the manufacturer of that MP5007R is? I can't recall having seen that logo ever before.
Is it a dual slope ADC IC?
It looks like a well-built interesting collection piece, pity about the LCD...

[TERRA Operative]

Other problems, I'm going to need to find a another display for it, as it's only a 3.5 digit DVM at the moment, the bulb has failed with the glass cracking, due to rusted pins, a common problem, it will take some time to find one that is known to work & doesn't cost a kings ransom, there are a lot of duds on ePay (I've been caught out before with these  ). And finally some of the lamps for the symbols are blown.

I got a few Burroughs B-5870ST tubes from a scrapped HP 8600A that I can send you for the cost of shipping if they are the correct type?

[EggertEnjoyer123]

New acquisition:

Agilent E4406A VSA Series Transmitter Tester 7 MHz - 4.0 GHz

It can analyze RF signals in both the time and frequency domain.

Found this on Craigslist for 350 USD and the seller was hours away but agreed to meet me at an in-between place for some gas money. It looks like it has never been dropped on its face and seems to work OK so far (it runs a self test on boot that passes and has nothing in the error log). The screen is not super-bright, but is very legible and has no burn-in.

I'm pretty sure that there is a computer inside there, so I'm going to have to back up the hard drive and replace it with an SSD if that is possible. I assume that all of the rubber bits on the floppy drive are hardened into brownish rock and I don't have any disks anyhow (nothing was supplied by the seller). It looks like it only has a one option (for EDGE, which does me no good). In addition, it's still old TE, so I'll have to make sure there are no leaking caps, drooling batteries, or lurking RIFAs.

This one should be fun.

https://www.keysight.com/us/en/product/E4406A/vsa-transmitter-tester-7-mhz-to-4-ghz.html

EDIT: Anyone have a line on the utility disk image or some rack ears?

I'm a bit late but there are no hard drives. All the software is stored on flash memory.

To get the 100MHz option: https://www.eevblog.com/forum/testgear/_free_-vsa-options/25/

Do the steps above, then update the firmware using https://www.keysight.com/us/en/lib/software-detail/computer-software/e4406a-vsa-transmitter-tester-firmware-201154.html

In the update program, you can select W-CDMA and it will install the 100MHz option. Note that there is not enough storage to fit all programs possible.

[artag]

So I went to the Dunstable Downs (Luton UK) Radio Rally today. Mostly getting rid of stuff but I did make a couple of aquisitions. A HP1661A logic analyser (96 channels). It does not complete POST, video goes out of sync. Probably a PSU issue. It did come with a good collection of leads, pods, clips and adaptors. And I have a 1662A (64 channels) so hopefully I can make a working 96 ch out of the pair. No brainer at £15.
Only other significant purchase was Collins 618T-3 and 714E. For non Collins fans that's an aircraft HF transceiver and control head. Covers 2-30MHz with 400W PEP output.

Robert.

Seems to have been a good day for logic analysers - not seen many of them there before. Especially that cheap. I got a 16700 with 3 16555A cards and the somewhat rare memory upgrade in it. Also saw a 16500A which was probably only good for the cable ends but cheaper than ebay for those alone - and disappeared fairly quickly.

[m k]

Any idea who the manufacturer of that MP5007R is? I can't recall having seen that logo ever before.
Is it a dual slope ADC IC?
It looks like a well-built interesting collection piece, pity about the LCD...

Chip under LCD is clearly its controller, so ADC the other one must be.
Seems that its type is recycled.

Where is reference, beside the input?

Measurement Science Conference
https://msc-conf.com/

[factory]

Any idea who the manufacturer of that MP5007R is? I can't recall having seen that logo ever before.
Is it a dual slope ADC IC?
It looks like a well-built interesting collection piece, pity about the LCD...

Chip under LCD is clearly its controller, so ADC the other one must be.
Seems that its type is recycled.

Where is reference, beside the input?

Measurement Science Conference
https://msc-conf.com/

I'm going to need to open this meter again, as the manual doesn't give all the information away.

The MP5007R is the analog IC (that's all it says), I don't recognise the 'M' logo either, yes the DMM is using dual slope integration. The CMOS digital IC under the LCD is listed as a 7104A, pinout is different from the well known ICL part, but has the same number of pins.

The 1.2V reference Zener (part number not listed) is fed from the 9V battery, via a 390k resistor to pin 22 of the analog IC, other side is grounded by a shorting link.



There is a 1N5850 (6.2V 10%) being used with the input circuitry.

David

[Robert763]

Had a closer look in the leads bag of my new HP 1661A logic analyser. Much to my surprise I found a mouse!
No, not a rodent a computer input device. It's a rare one though, a genuine HP-HIL mouse.
Probably worth more than the analyser....

[factory]

I'm guessing it's not used for HP logic analyzers?

Seems to have been a good day for logic analysers - not seen many of them there before. Especially that cheap. I got a 16700 with 3 16555A cards and the somewhat rare memory upgrade in it. Also saw a 16500A which was probably only good for the cable ends but cheaper than ebay for those alone - and disappeared fairly quickly.

Hope you have more luck with the 16700A PSU than some have had recently, the late ones use a crappy TOPSwitch device, that goes kaboom often.

David

[factory]

Other problems, I'm going to need to find a another display for it, as it's only a 3.5 digit DVM at the moment, the bulb has failed with the glass cracking, due to rusted pins, a common problem, it will take some time to find one that is known to work & doesn't cost a kings ransom, there are a lot of duds on ePay (I've been caught out before with these  ). And finally some of the lamps for the symbols are blown.

I got a few Burroughs B-5870ST tubes from a scrapped HP 8600A that I can send you for the cost of shipping if they are the correct type?

Unfortunately these are a different type, either a 5440 or 5441 tube or equivalent, the prefix, suffix & brand doesn't matter for this application, as long as it's functional & fits.

What is odd about the original parts, is they all have the left & right decimal points, but two don't use them and are specified & marked as the part with no points. Maybe a shortage of pointless tubes when this was made. 

David

[tggzzz]

Had a closer look in the leads bag of my new HP 1661A logic analyser. Much to my surprise I found a mouse!
No, not a rodent a computer input device. It's a rare one though, a genuine HP-HIL mouse.
Probably worth more than the analyser....

Look up the price of IC pin grabbers on fleabay 

[m k]

The MP5007R is the analog IC (that's all it says), I don't recognise the 'M' logo either

I found
MP5060 417601-yyww
MP5070 417603-yyww

Date codes have different years.
ePay has couple MP5060s in larger set.

So the manufacturer clearly real.

[factory]

OK dead trees beat the interweb in this case  , from one of the D.A.T.A. phonebooks in storage.



Given how little there is on the web for the chipset, it would be wise for me to find another Danameter & attempt to make a good one out of the two.

David

[m k]

My searches were full of Monolithic Power Systems.