Thursday, September 26, 2019

Tek 485 Dual Trace Scope

I Just sold this on eBay and had this originally written up here. As it was a back-up scope I purchased from my good friend but was only gathering dust, I wanted to get it into the hands of someone who would appreciate it and use it.

This scope is spare to my needs. I owned it for about five years and it has been stored and used in a cool, dry environment. It is immaculate inside and out and works. It is calibrated but may require some slight touch-up.

Note that all knobs and switches are present and intact and the CRT is exceedingly bright.

I am offering this for the price indicated and admit the shipping cost is high but that is because I am not sure of the destination and want to pack the unit carefully and securely. Will ship it insured and gladly refund the difference to the buyer.

It does not come with any probes but I will provide all necessary manuals on a DVD disk. The specs are as follows:

Material: Metal case
Shape: Tablemodel, low profile (big size).
Dimensions: (WHD)305 x 167 x 470 mm / 12 x 6.6 x 18.5 inch

350 MHz dual channel 4 inch scope.
Deflection factor 5 mV/div to 5 V/div.
Sweep rate 1 ns/div to 0.5 s/div.
Time base A and B.

The 485 is a 350 MHz, 1 ns/div portable dual-trace oscilloscope weighing 21 lbs, the lightest weight wide band portable oscilloscope on the market today. In addition to significantly advancing portable measurement capabilities, the 485 has many other new features. These features include selectable input impedance, adjustable trigger holdoff, EXT TRIG display, alternate delayed sweep, with trace separation control, vertical scale-factor indication, auto-focus, and B sweep intensity control. A human engineered front panel reduces measurement time.

Single function push buttons and automatic vertical scale-factor indication increases operator convenience.

The 485 vertical system provides wide bandwidth at full sensitivity with selectable input impedances. At 5 mV/div sensitivity (350 MHz at 50 Ohm and 250 MHz at 1 MOhm), the 485 offers more gain bandwidth than any other oscilloscope available today.

Selectable input impedance provides the capability to measure low and high impedance points with the same scope and without active probes. Internal detection circuitry protects the 50 Ohm input by automatically disconnecting when the signal exceeds 5 V RMS.

Automatic vertical scale-factor readout is provided by three light-emitting diodes located around the edge of each input attenuator knob. A quick glance at the readout tells the operator the correct on-screen volts/div even when the recommended 10X or 100X probes are used. The operator no longer has to remember to divide attenuation factors into dial settings each time he makes a measurement.

To complement the higher bandwidth, the 485 has a 1 ns/div sweep. A new alternate sweep mode expands the delayed sweep concept in portables. This feature allows the delayed sweep to appear alternately with the intensified main sweep. In this mode, the operator sees the intensified zone and delayed display at the same time. He always knows exactly where in a pulse train he is making a delayed sweep
measurement. The external trigger signal may be easily viewed on the 485 without disconnecting leads and resetting controls. A front panel push button automatically routes the external signal used to trigger Time Base A to the vertical deflection amplifier. This feature can also be used to
quickly make time comparisons between the signal of interest and the external trigger signal.

Additional Pictures