- on Test & Measurement
Practical useThe operation of the JDS6600 is clearly arranged. There are four function keys next to the display, the current function of which depends on the selected settings. The display shows the settings of both channels, the signal at the top also shows the selected signal shape. Most keys have multiple functions, which is a bit confusing in the beginning. For example, by pressing a CH-button once, you can switch to the other channel to set this, while pressing once on an already selected channel will cause this channel to be switched off. A long press on the CH2 button causes channel 2 to be shown at the top of the display with the waveform. Press and hold CH1 to return to the top of channel 1. Clear?
The keys work well, but when you press them you notice that the adjacent keys also move with them, that could have been solved a bit better mechanically. The values on the display are set by first selecting a number with two cursor keys and then changing it with the dial. With the frequency a lot of digits are displayed, which makes the setting a bit difficult. The OK button switches both outputs on or off, a somewhat strange name for this function. And with the MOD button, you can set sweeps, bursts and pulse widths, but no modulation. It's just a trifle, all in all it's quite easy to work with if you're aware of these peculiarities.
The output signals on the oscilloscope screen look pretty good, although based on the specifications (sampling-rate 266 Msamples/s, waveform-length 2048 points, 14-bit resolution) I had expected slightly nicer waveforms. FFT measurements of a sine wave in the audio area showed distortion remnants of just over 1%. The manufacturer mentions less than 0.8%, so that's just not achieved with my test specimen. Square waves, on the other hand, look pretty good, with fairly steep edges and little overshoot. The frequency progression is quite linear: Above 30 MHz, the output voltage increases by about 2 dB and then drops to about -1 dB at 60 MHz, not bad at all!
On the JOY-iT website you can download a program that allows you to operate the JDS6600 completely from your PC via a USB connection. As with much Chinese software, the design is not great, but everything works well. There are several tabs for the various functions, including one to compose your own waveforms. After trying it out for a while I made a sine burst for testing speakers in no time at all.
ConclusionThe JOY-iT JDS6600 has a lot to offer at a price of less than 140 euros. There are a few points that can be improved, but all in all you get a lot for your money. The only thing you don't have is a modulation option, but you'll find almost everything else in signal possibilities that you occasionally need for a hobby lab. No need to buy a professional device with a nice housing and a much higher price.