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Review: Protek 860, part 1 of 2
May 30, 2007

Protek Model 860FM, 60 MHz, price $1686 
(click here for the introduction to this series of reviews of four handheld oscilloscopes)

At first glance, the Protek 860 series oscilloscopes look more like a DMM. Why? They don’t have the vertical and horizontal screen controls that the other three units have. It has just 12 small buttons and a wheel (see photo). That gives the Protek 860 a simple look, but it means you’ll spend more time looking for the controls that you should. The wheel is easy to spin. The front panel has plenty of space for dedicated buttons. The protective boot is rather loose fitting compared to the others.

The monochrome screen is small and slightly harder to read indoors than the larger color screens of the other units (see photo), but this screen is the easiest by far to see in daylight. The stand is hard to use. To get the unit at the right height, you have to pull out the stand and push it back in to lock it into position. To close the stand, you must pull it out first to free it for closing. I didn’t do that and nearly broke the stand when closing it.

Protek’s yellow power button was hard to work. The button size and its case opening aren’t sized properly. Thus the button gets stuck. Not realizing that the button was getting stuck, I left the 860F on all night (under AC adapter power) because it didn’t turn off. I found the same problem when turning on the unit: I had to pull the power key up with my fingernails. Then I could get the unit to turn off and on properly. This problem needs addressing.

The Protek uses six AA size NiMH batteries. The batteries are in two compartments of three inline batteries each. The unit comes with the two 3-battery packs, but you canreplace them with and AA-size batteries. That’s good because you can get batteries anywhere if you need them. Opening the battery covers is awkward. You have to remove to battery covers and the cover also holds the stand to the case. I accidentally put the stand back in the wrong way. You also must remove the protective boot to remove the battery covers. And, it’s easy to put the boot on the wrong way because it’s open on both ends where the scope BNC connectors go. The clue is to look for the openings on one side the correspond to the power and USB connectors (see photo).

Press the “SCOPE” button and the soft keys control channel A, channel B, trigger, and time. Once you find the setting you want to change, press the function key until you select what you want. Some require multiple presses of a function key. I still prefer time and voltage buttons. The wheel lets you change settings such as vertical position and trigger level.

User functions include math. You can choose from direct waveform math (A+B, A-B, B-A) or FFT. You have a choice of four FFT windows. If you want to select an FFT window, use the Windows soft key (F4). Unfortunately, part of the window menu is obscured by the time-domain waveform display. Also, the time that the unit has been on overlays the “Blackman” window selection, making it difficult to read. These are simple firmware bugs the need attention.

The Hold/Save button lets you hold the displayed waveform as you’d expect. Holding the Hold button for two sec brings up the save menu. In the save menu, I want to save a screen to a USB flash drive. It didn’t work at first because I needed to use the Utility menu to activate the USB port. To create a file name, use the wheel and push the wheel click to select a character. I created a file called PROTEK0.SWV. I was able to recall the saved screen for later display.

Measurement functions

Pressing the measure button takes you to a menu where you can select from measurements to display. They include pk-pk, RMS, frequency, rise time, fall time, and others. Holding the button down for 2 sec enables the cursor function. The Measure button is marked “Cursor to indicate that. You can display up to four measurements. To select a measurement, press the corresponding soft key and use the wheel to scroll through the choices.

Cursor functions are straightforward. You get one or two X and Y cursors for measuring delta V and delta t. You use the wheel to move cursors.

Click here for part 2 of this review

(click here for the introduction to this series of reviews of four handheld oscilloscopes)

Posted by Martin Rowe on May 30, 2007 | Comments (0)