I received a Uni-Trend UTG9010C today after an impulse buy costing GBP55. The unit was described as possibly having an instability fault, but more of that later.
The unit arrived in it's original box with little or no signs of use, it even has it's screen protector still fitted. The units appearance is not displeasing to the eye in it's Ferrari Red and grey two tone colour scheme that all UNI-T kit wears.....but whats under the covers ?.....lets take a peek
Take a look at the attached pictures and all will be revealed.
The units case construction is acceptable, if a little tinny for my liking. The rear panel is fitted with an IEC socket but is otherwise pretty bare. All the action occurs at the front of the UTG9010C. The button action is good with a solid feel, whereas all the rotary controls except 'frequency' feel a little loose and fragile very much like those found on the Rigol DSO's. The displays are clear, but 7 segment LED's ... come on Uni-Trend ....get with the 21st Century and use LCD panels
Inside the unit, the story goes a little down hill
On opening the case (4 screws) I was confronted with a small mains transformer clinging on for dear life to the rear panel. It looked quite pitiful ! The main PCB is a vast expanse of unused space. Obviously a standard PCB area needed to be filled so that's what they did by spreading things out. The control PCB is behind the front panel but the actual microprocessor (Atmel 89C52) is located on the main PCB and runs from a 24MHz crystal. The control PCB is fitted with the venerable ICL 7107 LED 40 pin DIL A/D converter used decades ago in panel meters. Again, this is very old tech (cheap?) but as it just does the A/D on the output voltage I will not whinge too much. The frequency display appears to be driven via four 74LS164 SIPO shift registers.
Now the important bit...quality of electronic construction and performance.....
The electronic construction is all elderly through hole stuff, and in many places poorly executed with components taking on the appearance that they are trying to escape the shame of being attached to the PCB ! There is no excuse for such bad component installation....sloppy, very sloppy
The soldering on the main PCB is OK but that of the control PCB looks hand done with lots of solder residue. Rework ? Not great to see.
There is, I am pleased to report, a safety earth connection to the rear metal panel.... BUT that safety earth does not extend to the metal case shell except through the screws which considering the case is painted, is unacceptable. No continuity between the earth and case shell was found
In use the unit appears to perform "OK". The output is as I would expect. there is a short settling period after initial switch on but the unit appears to be stable in terms of frequency and output level. Longer tests will need to be carried out. The settling/warm up period was a tad excessive as instability in frequency did exist for around 1 minute after it was switched on. These units are not DDS and are not that stable so the specified tolerances must be considered when talking about stability.
So to sum up....
For GBP55 I am pleased with my purchase. If I had paid full price, around GBP180 + postage, I would have been less so. Once again we see a sheep in wolfs clothing....all the bling with little real content. The unit is not as bad as the UT804, that I so hate, but it is all old tech and poorly implemented on the design front & production line. I am left wondering whether Uni-Trend have two separate areas of design and production... one for handheld devices and another for bench equipment. The handheld multimeter's are just so much better designed and built !
Hope you enjoyed the tour of this function generator..... I suggest GW Instek may be a better source of such an instrument at the budget end of the market.