My 'new' Uni-Trend UTD1025C DSO has arrived - love it ! - Page 1
Forum section: electronics / general

author: Fraser
author_rank: Super Contributor
timestamp: January 12, 2012, 09:10:18 pm
content: I recently purchased a Uni-Trend UTD1025C handheld DSO to play with.The unit was advertised as having a fault on Channel A with no response to inputs. The UTD1025C is a 125MS/s colour twin channel unit with separate multimeter inputs. I calculated that it was worth GBP150 to me so made an offer....it was accepted.Upon unpacking the unit today I was immediately struck by the units excellent physical build quality and very good looking design. Once started, I was quickly shown a splash screen, followed by the scope screen. I am impressed with the clarity of the display and the user interface to control the unit. Upon checking the unit, I can find no evidence of use, it still has it's screen protector fitted and the case is without marks or scratches. The information page indicated that the unit was built in October 2010 so it's only just over a year old.Now back to the fault....the unit does have a faulty channel A as already declared by the seller. The channel provides no noise on the trace and I am already considering the culprit of this problem. Channel B works perfectly so I believe the ADC is likely OK. The front end of a scope is always vulnerable to voltage abuse so I am hoping to find that either the front end FETs or an amplifier IC has been fried. There is always the possibility that the unit left the factory faulty... on more than one occasion I have discovered a missing component or component leg unsoldered.I have my new SMT dedicated workstation completed now so I am prepared for what awaits me inside this marvel of technologyI will post a progress report and review of the unit (inside and out) in this thread for those who are interested.Pictures attached.Wish me luckAurora

author: bsgd
author_rank: Regular Contributor
timestamp: January 12, 2012, 09:31:53 pm
content: Hey, very nice unit!Im sure you'll get it sorted... good luckPlease keep us posted.

author: dith77
author_rank: Newbie
timestamp: January 13, 2012, 01:15:21 am
content: Nice and tidy little lab you've got there Aurora!!!

author: vtl
author_rank: Regular Contributor
timestamp: January 13, 2012, 03:29:57 am
content: Great price and nice find!Since theres no noise on the trace, the signals obviously not getting through. If you have another osciloscope you can trace through the input circuitry while you are feeding in a test signal and see where everything stops. Since you have a channel B the channel A would probably be duplicated making it easier to compareGood luck

author: slateraptor
author_rank: Frequent Contributor
timestamp: January 13, 2012, 03:54:39 am
content: Your workbench is so...tidy. How do you get any work done?

author: hacklordsniper
author_rank: Frequent Contributor
timestamp: January 13, 2012, 06:34:21 am
content: Quote from: slateraptor on January 13, 2012, 03:54:39 amThose who have tidy benches know how is work done without mess

author: Fraser
author_rank: Super Contributor
timestamp: January 13, 2012, 08:35:53 am
content: Thanks for the comments guys.Reference the workbench.....It is located in my garden office/lab, hence the '1970s look' wood panelling .....I have two work areas in the lab. One is for SMT work and rework, with all the required tools, the other is set up for conventional 'through hole' activities plus diagnostics and analysis. I am fortunate to have a dedicated space for my electronics work. Why is it so tidy ? Well I have literally just finished re-organising my lab and this new SMT area has yet to be used in angerI managed to buy some decent PACE equipment over the past few months and it is now deployed for use. I have moth balled my older and bulkier Weller desoldering and soldering equipment. Note the soldering iron stands still contain virgin tip wipe pads !I wanted the lab nice and organised as I was finding that I was working in a clutter on the benches and one project got in the way of another..... I am in no way this tidy normally ! One of my New Years resolutions was tidy it up and get my test equipment rationalised so that I could see the wood for the treesI still have to deploy a decent ESD protection system but I am currently using a portable mat and straps, as the need dictates.For interest, the PCB stand in the picture is a cheap artists easel from a UK discount book store...it cost GBP10, has several operating angles, contains a usefull drawer and is antistatic (wood!)It certainly helps me get a good operating angle on PCB's. I also have the Aoyue bench PCB stand/vice for horizontal working where the PCB needs to be secured in place.

author: Fraser
author_rank: Super Contributor
timestamp: January 13, 2012, 06:53:08 pm
content: Well I have just opened the UTD1025C ...phew, it wasn't as bad as I thought it would be.Some interesting observations on initial inspection....... like the PCB being marked up as the top spec UTD1102C.It is heavily populated with Analogue Devices Chips.The largest IC is an AD ADSP-BF531 400Mhz Black Fin processor. There are two AD9481 250MS/s ADC's, one for each channel (decent spec part...no cost cutting here) .The SDRAM is a Zentel 8*16 A3V28S40ETP.Construction is OK but there are some minor modifications that I will tidy up before re-assembly.More later

author: Fraser
author_rank: Super Contributor
timestamp: January 13, 2012, 09:30:43 pm
content: Ok here is a 'teaser' photo of the UTD1025C main board.The heat transfer blocks are very thick and split but I believe they will still work OK.My very early days comment on the construction is that the PCB is well made and populated BUT Uni-Trend really need to look at up-skilling the operatives who carry out post build modification work. I am seeing soldering of modifications that is as poor as that seen inside the UT-61E and it detracts from what looks to be a very well designed unit. I will be tidying my unit up before re-assembly.Aurora

author: Unknown
author_rank: Unknown
timestamp: January 14, 2012, 07:10:39 am
content: Looks quite decent, but indeed some dodgy soldering on the power supply components (diodes). It appears that both channels have a common ground, unlike the Tek handhelds and later Fluke ScopeMeters. High voltage isolation of the scope channels seems to be less than in the recently posted ScopeMeters pictures, but I guess the inputs are also rated for a lower voltage. Apparently no isolation slots in the PCB or magnetic/optical isolation. I'm surprised to see what looks like relays in a battery powered instrument. Probably no schematic available? No obviously blown components, good luck tracing the signal. Lets hope it's something simple like clamping diodes.

author: Fraser
author_rank: Super Contributor
timestamp: January 14, 2012, 07:55:08 am
content: Hi alm,Yes, this is certainly not as sophisticated as the Fluke or Tektronix designs. There are some quality issues around the way the input sockets have been installed as well. I am intending to inject a signal at the channel inputs and trace the signal path through to the ADC's ....lots of optical magnification will be needed ! A good design feature is the fact that I can reattach the whole front panel assembly to this main board module and still have total access to the channel amplifiers for measurements. This contrasts with some equipment that I have worked on that is built in such as way as to prevent any access to the required components whilst it is assembled. Such equipment requires special ribbon cable extension kits etc. This unit should be techie friendly to work onWith regard to the design of the amplifiers....The channel input feeds into a MOS AC/DC switch followed by a relay controlled attenuator. The attenuator output then feeds two JFETS. The output of the JFETs feed a bipolar transistor that in turn drives an OPA695 amplifier. The OPA695 output them drives an AD8337 video amplifier IC. The input path does not have any visible clipping or clamping diodes.My current bet is on blown front end FETs or a production defect. I shall enjoy solving this little faultI am happiest when delving inside a piece of faulty equipment, hunting the elusive failed component .... some people do crosswords, others Sudoko...I do electronic diagnosticsPictures of the A & B Channel amplifiers attached.IDs of components:Mechanical Relays are AGQ200A4H low power 31mA typeY241Sis a MOS switch for dc blocking bypassHVBis an AD8337 video ampA71Lis an OPA695HKYis an AD80098512is an AD8512U203&U204are the input JFETSU205is the bipolar transistor fed from the FET stage output.All nice quality components and not 'Won Hung Lo' brand !Aurora

author: Fraser
author_rank: Super Contributor
timestamp: January 14, 2012, 10:53:03 am
content: Regarding schematics for Uni-Trend equipment........As with many manufacturers, Uni-Trend do not publish their schematics in the public domain. Though unhelpful to techies like me, this is their right and I respect their IPR. Sometimes you meet an agent who will offeradvicewithout breaching his/her NDA or companies IPR. Such an agent is to be valued and not abused.I contacted Uni-Trend requesting schematics for just the Channel A amplifier. Whilst the initial response was hopeful, sadly the communications ended once I had provided my location details. I then knew I would have to work out the signal flow using Channel B as a reference for tests and hope that there are not too many control signals at work in the stage. It has proved very helpful that Uni-Trend do not carry out that annoying anonymisation of chips crap that some consider necessary.It is at this point that I must thank fellow Forum member, William. William has discussed the UTD1025C with me and our conversations have better equipped me for the diagnostic work on this little DSO. William is also interested in my opinion of the UTD1025C as a DSO, and in terms of its construction.Why is William so interested in performance and quality ? .....well he owns Labtronix and takes the quality and performance seriously. I am very impressed with Williams attitude towards the products he sells. A sign of a very decent person running a good retail business

author: Fraser
author_rank: Super Contributor
timestamp: January 15, 2012, 12:11:18 am
content: What an anti climax !I completed stripping the unit into its component parts ready for testing and then reconnected the front panel and battery.After connecting a signal to the Channel A input and switching on the unit, it displayed a perfect sine wave ! Channel 'A' is ALIVEThere are some possible reasons for this miraculous self repair, amongst which is the possibility that I have removed a short in the amplifier during disassembly. There could also be an intermittent fault in the amplifer and finally, the fact that I removed the battery may have forced a cold boot that has re-enabled Channel a after a control line lock-up (feasible ?)I was all ready with the scope probe to go signal hunting and the damn thing went and worked !!!Tomorrow I will do some digging around in the unit to see if it continues to work OK. I will also be looking to rework some of the hand soldering that doesn't meet my standards. That capacitor on top of the Black Fin 400MHz processor has got to go for starters !Aurora

author: Unknown
author_rank: Unknown
timestamp: January 15, 2012, 12:31:38 am
content: If it's any consolation, there's still a chance that it's intermittent and it may even stop working again once you reassemble it.

author: Fraser
author_rank: Super Contributor
timestamp: January 15, 2012, 12:38:12 pm
content: Hi alm,You never know !Even if the fault has been accidentally removed during disassembly, I still want to have a good look around the unit to better understand it and the modifications that are fitted. I am still interested to see that the 250MS/s Analogue Devices ADC's are used. That kinda puts the Rigol DS1052E to shame with it's overclocked 100MHz parts ! My UTD1025C may be capable of 250MS/s or more in hardware but sadly I suspect the firmware is the limiting factor here. Changing the contents of that is well beyond my talents. I will be content with a nice colour handheld 125MS/s DSOI have my faithful DS1052E for work up to 100MHz.Even if the unit is now fully operational and fixed, do not fear... I have a nice stock of good quality (but faulty) equipment awaiting my attention...its just that the UTD1025C totally seduced me with its good looks and manged to jump the queueAurora

author: hacklordsniper
author_rank: Frequent Contributor
timestamp: January 16, 2012, 01:21:33 pm
content: Sometime ago somebody posted a file full of UNI-T schematics, i still have it saved somwhere.

author: Fraser
author_rank: Super Contributor
timestamp: January 16, 2012, 09:48:25 pm
content: I have news regarding the fault on the UTD1025DThe unit DOES have a fault after all....just as alm suggested there might beI was doing some power supply voltage checks and discovered that a 5V power supply series inductor 6L1 was open circuit. This inductor is in series with a dedicated supply line to the Channel A 74HC4094, which is a tri-state 8bit serial shift register. The supply serves no other components. The chip is involved in the associated channel select and settings like attenuator etc. If it isn’t working, no channel activation at the amplifier stage. Sound familiar !Two mysteries existed1. If the supply to the 74HC4094 was removed by the failure of 6L1, how could the channel have worked the other night ?2. What destroyed inductor 6L1 ?I have the answer to both questions.1. The supply to the 74HC4094 WAS missing the other night and the Channel WAS operating… the chip is CMOS technology and without a supply odd things can happen. The floating supply pin 16 is connected to output enable pin 15 (they are wired together), its logic was effectively floating on the various inputs and outputs. The result by pure fluke was that the correct outputs activated the CH A amplifier. Why did this not happen when the unit was assembled ? read on……..2. The 5V output from inductor 6L1 feeds directly to the 74HC4094 IC, and nowhere else. The 74HC4094 was tested for a shorted supply rail, none found. It was then noted that there was a decoupling capacitor next to the chips power pins. This SMD capacitor looked very close to part of the metal channel screening can. In fact it looked way too close for comfort. It was clear that if there was a small movement in the adjacent metal screen, it would touch the SMD capacitors +5V end and short it to ground. This theory was tested by re-fitting the screening cans lid which is a clip on fit and very tight. Checking the supply rail to the 74HC4094 now indicated a dead short to 0V ! In this state the 74HC4094 supply and OE pins are tied to 0V by the short and the IC is inactive. The puzzle was solved. The supply rail to the Channel A control IC had been lost due to a mechanical short to 0V, that in turn destroyed the series inductor. The short is only present whilst the screening can lid is fitted and applying compression force to the sides. An interesting little fault ;-)I will be fitting a new inductor and modifying the metal screening cans on both channels to prevent this short occurring again in the future.I attach a picture of the offending screening can. Note on the right hand side, the point at which the two ends meet and are soldered. The inner lip is bent in towards the 74HC4094 and the decoupling capacitor. This is the part that causes the short of the 5V rail to 0V.Aurora

author: Unknown
author_rank: Unknown
timestamp: January 16, 2012, 10:41:49 pm
content: Nice work on the diagnosis! Not only did you find the problem, but you even figured out why the fault was intermittent. The lack of insulation/clearance between the cap and the screening is a design issue in my opinion.

author: Fraser
author_rank: Super Contributor
timestamp: January 16, 2012, 11:24:12 pm
content: Thanks alm....I have enjoyed this little investigation....I don't like it when faults appear to clear themselves...most unsettling !I will reassemble and review the unit shortly but I want to tidy up the odd rough solder joint here and there first, and try to better understand the design in the processI still very much like this little DSO...... I think it will be a keeper.Aurora

author: Fraser
author_rank: Super Contributor
timestamp: January 22, 2012, 02:03:41 pm
content: Some pictures during the disassembly. More detailed ones available if anyone needs them.The UT1025C PCB's are heavily populated with intergrated circuits from Analogue Devices and Linear Technologies. The pair of AD ADCs are overspecified at 250MS/s on this 125 MS/s DSO. There appears to have been no cost cutting on this design with qualaity branded components used throughout.I am very pleased with the design of the PCBs and automated component assembly. Post build hand soldering is functional but I am choosing to rework those areas to tidy them up.The UTD1025C is a very nicely designed and constructed unit. There was a physical production fault on mine, but apart from that it should prove reliable.Aurora

author: Fraser
author_rank: Super Contributor
timestamp: January 22, 2012, 02:05:13 pm
content: More pictures

author: tinhead
author_rank: Super Contributor
timestamp: January 22, 2012, 02:35:05 pm
content: Quote from: Aurora on January 13, 2012, 06:53:08 pminteressting ... in principle all you need to hack this baby to UTD1102C is different firmware.

author: Fraser
author_rank: Super Contributor
timestamp: January 22, 2012, 03:12:04 pm
content: There are unpopulated postions for two more ADCs on the rear of the PCB. I suspect the 500MS/s model has these fitted.As you say, it is likely firmware controlled as teh PCB is marked up as the 1102C.

author: Jegen
author_rank: Newbie
timestamp: February 23, 2012, 11:07:10 pm
content: Hello allI have a UNI-T UTD1025c without a Power supply DC Adapter, can someone tell what is the original voltage of the DC Adapter

author: Fraser
author_rank: Super Contributor
timestamp: February 24, 2012, 03:15:17 pm
content: Believe it to be 9V dc at 3A centre positive but will confirm laterAurora

author: Fraser
author_rank: Super Contributor
timestamp: February 24, 2012, 05:25:53 pm
content: I have just checked the adapter supplied with my DS1025CIt is aRegulated9V dc 3A rated with a centre positive connector. The unit is a compact switch-mode design.The DS1025C is rated at 20VA Max in the user manual which is 2.2A at 9V, so the power supply I have provides some current 'headroom' and doesn't run hot.Did you get the two plug-in current shunts with your unit ? If so, I would love to see a picture of the internals as I hope to make my own. Alternatively the resistance across the terminals on each range would be helpful. I already have a 30A shunt module from MAC tools but the tripple range low current unit appears to be unavailable.Please be aware that there is a design flaw in the DS1025C channel screening which can lead to loss of power to a channel and failure of the series inductor as detailed above. If you have no warranty on your unit, I recommend you take action to prevent this failure occurring at some time in the future. Some insulation material between the screen can and the SMD capacitor would workAurora

author: Jegen
author_rank: Newbie
timestamp: February 24, 2012, 06:28:26 pm
content: Thanks Aurora!Yes i have the two plug-in current shunts, i make today some pictures of the internals and than i post it

author: Fraser
author_rank: Super Contributor
timestamp: February 24, 2012, 07:45:05 pm
content: Many thanksMine came with PSU onlyIf the resistors inside teh Shunts have a value written on them that would be great too.I had to buy a 9V 3A power supply for another project today and found one in Hong Kong it looks decent enough from the outside and isn't pretending to be a brand name so may be reasonably made.Here is the link for one:http://www.ebay.co.uk/itm/1pc-9V-3A-Switching-Power-Supply-Adapter-UK3-/160744079229?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item256d17ff7dBest WishesAuroraUPDATEThis PSU arrived from Hong Kong.Whilst it looks well made it is truly tiny in comparison to other 3A PSUs that I own. This is more the size that I would expect to be rated 1 to 1.5A max. I do not trust its rating and so will not be using it with the UTD1025C just in case its been over rated.

author: Jegen
author_rank: Newbie
timestamp: February 24, 2012, 08:36:34 pm
content: Here are the Pictures

author: Fraser
author_rank: Super Contributor
timestamp: February 24, 2012, 09:15:23 pm
content: Many thanks for the pictures, very informativeMy Bluepoint/Snap-on 20A/30A shunt module differs a little to the 4A/6A unit that you have and no sign of a fuseI attach some pictures of it.Best WishesAurora

author: ron
author_rank: Regular Contributor
timestamp: February 24, 2012, 09:25:38 pm
content: Fuse? How could you install a fuse without defeating the operation of the shunt?

author: Jegen
author_rank: Newbie
timestamp: February 24, 2012, 10:04:05 pm
content: Aurora are the pictures enough or do you need a wiring diagram for 6mA to 600mA "shunt"

author: Fraser
author_rank: Super Contributor
timestamp: February 24, 2012, 10:20:10 pm
content: Ron,These units are deigned to plug into the multimeter voltage input socket of the UTD1025C. The Shunts just produce XmV/A and the UTD1025C measures the voltage and displays the current. They have a pair of IN connectors (for the probes) and a pair of OUT connectors (connect to the UTD1025C). It is perfectly normal to place an HRC fusein serieswith the positive feed from the input connector before it reaches one end of the Shunt. This is a safety overload device, as found in any quality multimeter design. To provide a safety overload protection for these particular high current modules, fused probes would be needed. It is sometimes found that cheap current measuring circuits incorporate a thin fuseable PCB trace as a cheap 'last ditch' safety device. No sign of such here.Hope this makes the situation a little clearer.Aurora

author: Fraser
author_rank: Super Contributor
timestamp: February 24, 2012, 10:21:41 pm
content: Jegan,I sent you a PM. If the schematic for the low current module is available from you, I would be most grateful for it.Kindest RegardsAurora

author: Unknown
author_rank: Unknown
timestamp: February 24, 2012, 10:46:25 pm
content: Funny, there appear to be protection diodes in the 4-400 mA shunt, but none in the 4 A / 6 A shunt. I also love the 'do not open unless you are specialist' comment. Is anyone going to claim they're specialized in these plug-in shunts?

author: ron
author_rank: Regular Contributor
timestamp: February 24, 2012, 11:00:44 pm
content: AuroraThanks for your reply-- yet I don't get it. What are you wanting to protect?For example an 11amp HRC Buss Fuse has a nominal resistance ~ .017ohm. Putting it in series with the shunt would induce error. Putting it in series with the output (between shunt and meter) seems pointless. What am I missing?edit: I might be wrong about the resistance of the fuse, but it is appreciable and not thermally stable. If that weren't the case one could just use a fuse for the shunt itself...no?

author: Unknown
author_rank: Unknown
timestamp: February 24, 2012, 11:19:47 pm
content: You connect the fuse in series, but connect the outputs just across the shunt resistors:Code:In- +| |+-[---]-+-/\/\/-+| |- +OutThe fuse does not introduce any error, it only increases the burden voltage.You are trying to protect the shunt resistor, leads and the user, since the failure mode may be rather violent. Imagine connecting the shunt across a 48 V UPS battery pack or mains. Those may source hundreds of amps, causing extreme heat in the shunt and leads, possibly melting them and injuring the user.

author: T4P
author_rank: Super Contributor
timestamp: February 24, 2012, 11:42:48 pm
content: Let's see ... your lab ...Aoyue "Int"852 .5 Pace soldering stations (!)Something that looks like a X-tronic 4040 / more like a 850d+1 Large pace vacuum desoldering stationa weird tall soldering station on the left side on the desk that i think must be a metcal ? or is it ersa ? or is it some funny brand ?I actually bought one of those blue BEST Magnifying lamps then now i switched to a 11W florescent magnifying lamps .Love those PCB vices , used to use a stupid old third hand thing nowdays i use a panavise "vacuum base vice" clone .I have 2 936's and both are very different in characteristics , my 858d+ is broken , thanks to a overheating triac and a broken mica insulator paper on the heating element . ( I love to stay minimal and small , hate diaphragm pumps at the same time , lousy ones just rattle the shit off my table . )Anyway what's the thing with pipes underneath the desoldering station ? A solder pot ?Just under the black slanted pace soldering station , another pcb holder ?What's that blue box there ? Ohh some lovely stuff , can you like name the rest of the 4 things with many buttons and knobs ? ( underneath the blue box )2 Lamps . I use a IKEA Tertial lamp with a 22W CFL .I'm having problems looking for a "flux remover" or "solvent remover" thing here ...

author: ron
author_rank: Regular Contributor
timestamp: February 24, 2012, 11:54:03 pm
content: almThanks for the sketchBurden voltage is the source of error I am referring to. I am thinking of shunts on the order of .01ohm. Using a hand-held shunt to measure hundreds of amps is something I'd not attempt.I'd just use a clamp meter or wait for Dave's next kit ... The MEGA-MACRO CURRENT.

author: Bored@Work
author_rank: Super Contributor
timestamp: February 25, 2012, 12:01:51 am
content: Quote from: ron on February 24, 2012, 11:54:03 pmThis is not about what you intentionally do, but what you accidentally do. E.g. accidentally sticking the probes in parallel to a powerful voltage source.

author: Fraser
author_rank: Super Contributor
timestamp: February 25, 2012, 10:29:52 am
content: As an additional note regarding my 20A/30A shunt from Bluepoint-Snap-on. This unit was sold for automotive diagnostics. I mean no disrespect to auto electricians, but when they cock up a test it can involve many hundreds of Amperes from a sizeable energy source. The result of making the wrong connections or measuring an unexpectedly high current flow would normally be a blown HRC fuse and the cost of replacing it. With the unit I have, no fuse in the same scenario will mean a very melted shunt module casing at the very least as the shunt will glow like a lampWith regard to accuracy, I should be honest here....the UTD-1025C is a lovely handheld DSO, but the multimeter built into it is nothing special at all. The specifications for accuracy tell the whole story here. The multimeter is a separate module within the unit and sits between the Channel modules. Its the grey module in my photographs. It is a convenience to have rather than a seriously accurate meter. I find the requirement to insert current shunt modules an inconvenience and odd decision on the part of Uni-Trend....an after thought ? Probe and pocket multimeters have the same sort of characteristics as the UTD-1025C multimeter module and they often do not support much in the way of current measuring capability either but the low current capability module could easily have been built into the oscilloscopes case as no large shunts are involved.To summarise, the shunt modules are a compromise solution to provide a simple multimeter module with some current measuring capability. They are no way lab quality but then neither is the multimeter moduleThere should still be a Fuse though, especially in an automotive environment 30A current shunt !All the bestAurora

author: Fraser
author_rank: Super Contributor
timestamp: February 25, 2012, 10:53:16 am
content: DaveS,Thanks for your interest in my lab. I will provide the list of my soldering kit laterThe blue box is a 100dB Telonic RF attenuator. The units underneath are various AF & RF signal generators plus a frequency counter. I will provide detail later as my better half has some jobs for me to do.RegardsAurora

author: Fraser
author_rank: Super Contributor
timestamp: February 26, 2012, 11:55:10 am
content: Dave.S.I can assure you I'm not a wealthy techieI repair Lowe HF receivers for free as a service to the user community so I am no businessman either !I have built up my current inventory of equipment over 30+ years and have been an electronics hobbyist since the age of 7 when I repaired cassette recorders and radios. Recently I did a refresh of some of the equipment and I will admit it has cost me more than I would have liked, but you have to equip for the latest technologies if you intend to service them.As a hint that I may regret making public...I often buy faulty test equipment that people tend to shy away from and then repair it. Some are easy (like the UTD-1025C) others are royal pains and take a lot of time and effort BUT buying a multi thousand dollar piece of test equipment and repairing it, all for a total coat of less than $100 does give me a buzzI have done this often and its usually PSU related faults that are cheap to repair.With regard to my soldering kit.... I used to use a Weller Magnastat soldring iron and it is still on my bench. I was gifted two more and a Weller desoldering station as the commercial world is moving to newer technologies. I was in the right pace at the right time. The Pace soldering kit has all been purchased in 2011 when I upgraded my capability to SMD working. All of my Pace equipment was bought from ebay auctions. A brand new ST45 soldering station with PS70 iron and stand cost me GBP45A real bargain. I purchased some used, but great condition, PS40A clever digital soldering stations very cheaply (around GBP30 I think) One had a good PS70 iron whilst the other had a well used older IR-1 iron. I have since bought three brand new PS70 irons at GBP30 each which is great considering the elements are more than GBP70each. There was an analogue Pace base station being sold for around GBP20 so I bought that as well just in case I needed an extra base station in the future. The Pace VF100 desoldering gun is a work of art and true industrial quality. That cost me GBP60 brand new in the box from a recycling seller on ebay. They normally cost a small fortune new from Pace ! The W.E.P hot air and soldering station cost me GBP80 new and delivered from a UK seller. The Aoyue hot air station came from an ebay recycling seller and was stated as having a faulty LED display segment. It cost me GBP29 and the fault was just a poorly seated chip on the display board. Its as new as it was a customer return. I bought a bran new pair of OKI SMD soldering tweezers for GBP16 from a recycling seller on ebay in the hope of modifying a base unit to run them, or find a cheap OKI base unit. After 6 months I purchased a perfect condition OKI digital base station for GBP20 so I have an industrial quality professional soldering tweezers set for just GBP36My last purchase was a lovely Aoyue (CSI branded) desoldering gun for through hole work. It cost around GBP60 and works like a charm. For information, the diaphragm pumps in my hot air and desoldering stations are ALL quiet in operation and produce virtually no noticeable vibration on the bench. Buyers MUST remove the transit lock down screws as failing to do so make the unit very noisy and causes masses of vibration. This has been the cause of some customer returns when the user did not read the manual. Again, you can win if you buy such from a recyclerJust remove the 1 to 3 red screws an all is well. If a unit with a diaphragm pump vibrates or is very noisy, something is wrong and should be investigated.have recently purchased a PACE TF200 ThermoFlow hot air station for a very reasonable sum. It is without the heater cartridge....the heaters cost GBP500 (yes GBP500!) so no surprise that there was little interest in this superb unit. When working, it can deliver accurate heat in a process controlled manner with ramp up, maintain and ramp down sequences for BGA work and similarI bought it because I like a challenge. I have done some investigation of the design and discovered that I can probably use a cheap Chinese sourced heater assembly designed as a high quality replacement for the 852DE Auoye stations. The heater has the required voltage rating, wattage and thermocouple built in to the tipThe other challenge was to modify the handpiece and to make a heat tube for the element. The answer was to buy a Chinese replacement 852D+ standard handpiece and use it as a replacement part or a parts donor. The cost to date of this ongoing modification...GBP5 for the high quality ceramic insulator element and GBP8 for the 852D+ handpiece. The unit was worth every penny I paid for it in terms of the fun I am having solving the puzzle of how to fit a different heater and heat tube. When its working it will be a great SMD tool to use.As you can see, it is possible to equip yourself with very good quality equipment for a reasonable price and significantly less than buying new of similar quality. I take great pride in my equipment and tools but I am not too proud to buy used equipment and then repair or restore it to its former glory. For me that is part of the joy of electronics.My advice is t search for a local industrial electronics recycling company, they tend to have vast piles of amazing kit that they just wish to shift quickly for a small profit per item with no guarantee or warranty given. I have a 'pet' recycling company in my town, and can pick up equipment that is heavy and so avoid postage costs as wellRohde and Schwartz, Marconi, HP...... all manner of equipment is often 'binned' by big commercial workshops and labs when they are too old for manufacturer support or calibration failures.Aurora

author: hugos31
author_rank: Regular Contributor
timestamp: February 26, 2012, 12:05:02 pm
content: I like, the order of his laboratory

author: Fraser
author_rank: Super Contributor
timestamp: February 26, 2012, 12:06:31 pm
content: Not any more !....it was just completed when I took the photos...there is kit all over the benches at the momentAurora

author: Fraser
author_rank: Super Contributor
timestamp: February 26, 2012, 12:13:53 pm
content: I was asked what the unit was on the left that looked like a solder POT....it's a PACE HS200 Solder Wave PCB preheater for SMD work. The controller is fully digital and can produce all manner of temperature gradients for a particular PCB. Conductive, radiated and forced air convective heat is available as required. It a real beauty that I stumbled up from a recyclers ebay auction. I got it for GBP32 because people didn't know what it was. All i had to do was make up some silicon air hoses for it (GBP3 from my local Aquarium shop) I later found an 'as new' controller on ebay and won it for GBP5 with no other bidders....people didn't know what a 'Heat Wave controller' wasThe controller retails at some crazy price from PACE so now I have a good spare in case my first unit dies.Thank heavens for recycling companiesAurora

author: Fraser
author_rank: Super Contributor
timestamp: February 27, 2012, 09:19:28 pm
content: The spare heaters that I just purchased from China are a high quality replacement for my hot air stations. They are a spiral wound heater element wrapped around a ceramic former and have the thermocouple mounted at the end. The heaters came with a free replacement Mica insulator tube which would solve that problem for you. TRIACS are cheap so it would be worth fitting a new one.The auction for the heaters is here:http://www.ebay.co.uk/itm/220V-Hot-Air-Gun-Heating-Element-Core-SAIKE-852D-/280547486260?pt=BI_Electrical_Equipment_Tools&hash=item4151eeea34A mica former is shown in the picture bu that has been upgraded to ceramic.The W.E.P hot air station is the 852D+ diaphragm pump model with a hot air handpiece and a soldering iron.I also bought the cheap Atten 858D+ but I can't really recommend it as the unit, as delivered from China, is not well finished and needs work to make it safe. A UK company (Labtronix.co.uk) does all the safety upgrade work before selling these units to the UK public so his should be OK.The IR station that you mention sounds very interesting as the price is very low for such a device. The IR lamps alone can cost around $100 each but the prices have been dropping recently. I understood these units to be very well suited to BGA rework but I'm not sure about other SMT rework performance. Care to share the details of the supplier here ?Aurora.

author: dean
author_rank: Newbie
timestamp: March 27, 2012, 09:47:06 am
content: Hi Aurora.I envy your lab and order which reigns in your table. The work done by you is worthy of all praise.Let me ask you opinion, is it worth buying UNI-T utd1102c 1100$ or preferably purchase HANTEK DSO1102B 660$? I saw a good quality UNI-T in your pictures, but it can save costs with HANTEK. Please, let me know, because i am in great confusion with choose between two models. I am not a professional, but I love to do something interest with electronics. Thank you.

author: T4P
author_rank: Super Contributor
timestamp: March 27, 2012, 07:37:03 pm
content: Owon SDS1102V get the new ones with VGA And Lan .around 500$ who can complain ?

author: Fraser
author_rank: Super Contributor
timestamp: March 27, 2012, 09:49:29 pm
content: Dean,I have to be very honest here and state that I only bought the UNI-T UTD1025C because it was a fraction of the normal price due to a minor fault (that I have now repaired). The compromise of the handheld models is sampling rate and the associated lower 'bang per buck' rate when compared to portable bench DSO's like the Rigol DS1052E . I personally like my Rigol DS1052E DSO and it is very portable, just not handheld.....1GS/s + easily user upgraded to 100MHz true analogue bandwidth....for only around $300....a very good bang per buck ratio and other similar high spec models are now available.Handheld DSO's are a bit of a luxury item suited to the VERY mobile technician. In many cases a small bench DSO is equally useful. I regret I cannot offer advice on the different models of handheld DSO as I have no personal experience with units similar to the UTD1025C. All my previous handheld DSO's have been cheap Vellerman and TTi units that are very inferior in terms of performance. I can't even give you a thorough review of the UTD1025C as it awaits my attention after an unfortunate period of illness struck me down and prevents me 'playing' in the lab.It is my view that the colour handheld DSO are very attractive but do not pay a significant premium for this portability and small size unless you really need it.Hope this helpsAurora

author: dean
author_rank: Newbie
timestamp: March 28, 2012, 01:44:43 am
content: thank you Aurora, you right, rather, it is really a luxury item for me. I do not need portability so in order to pay two prices. Right, right. This is cute device but i think i give up this idea at least a year. Thank you for your wise opinion.I wish you all the best, Dean.

author: shipu
author_rank: Newbie
timestamp: March 14, 2013, 05:57:41 pm
content: Quote from: Aurora on February 24, 2012, 05:25:53 pmWouldn't a plain old transformer-based DC-adapter be the better choice? I mean with a switched DC adapter, the Oscilloscope is not really floating. Can't this cause problems when e.g. the probe's GND is connected to the mains? Or to any potential of a DUT's PSU?Shipu