LG 5020G 20 MHz Oscilloscope Dual Trace Working 9020, US $100.00 – Picture 0

LG 5020G 20 MHz Oscilloscope Dual Trace Working 9020, US $100.00 – Picture 1

LG 5020G 20 MHz Oscilloscope Dual Trace Working 9020, US $100.00 – Picture 2

LG 5020G 20 MHz Oscilloscope Dual Trace Working 9020, US $100.00 – Picture 3

LG 5020G 20 MHz Oscilloscope Dual Trace Working 9020, US $100.00 – Picture 4

LG 5020G 20 MHz Oscilloscope Dual Trace Working 9020, US $100.00 – Picture 5

LG 5020G 20 MHz Oscilloscope Dual Trace Working 9020, US $100.00 – Picture 6

LG 5020G 20 MHz Oscilloscope Dual Trace Working 9020, US $100.00 – Picture 7

LG 5020G 20 MHz Oscilloscope Dual Trace Working 9020, US $100.00 – Picture 8

LG 5020G 20 MHz Oscilloscope Dual Trace Working 9020, US $100.00 – Picture 9

LG 5020G 20 MHz Oscilloscope Dual Trace Working 9020, US $100.00 – Picture 10

Lg 5020g 20 Mhz Oscilloscope Dual Trace Working 9020

US $100.00

Tualatin, Oregon, United States
Jan 29th

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This is an LG Precision OS-5020G dual-trace oscilloscope with built-in 1 MHz function generator. This same model has been branded "Goldstar", or "Lucky Goldstar", and sometimes appears as a model number 9020G. The same model is still being built and sold by E-Z Digital, which apparently purchased the oscilloscope division from Lucky Goldstar. I purchased this unit around 1997, and it is still in excellent cosmetic and working condition. All the controls and switches operate smoothly with no noise. The unit is well within its calibration specs. The CRT display is 8x10 cm, with an internal, non-illuminated graticule. Vertical sensitivity is 5 volts per division to 5 millivolts per division with a bandwidth of 20 MHz. Pulling the variable knob out engages a 5 times magnifier, giving a 1 millivolt per division maximum sensitivity, but with a bandwidth of 7 MHz. The "dual" mode automatically switches between chopped and alternate sweep depending on the sweep speed, giving the best appearing display at all sweep speeds. There is an "add" mode which displays a single trace consisting of the sum of both channels. There is a channel 2 invert switch which, when used with "add" mode, displays the difference between the two channels, also known as "differential mode". Horizontal sweep ranges from 200 nanoseconds per division to 0.2 seconds per division. A 10X magnifier increases the maximum speed to 20 nanoseconds per division. There are TV-V(ertical) and TV-H(orizontal) trigger modes to facilitate display of video signals (of limited use now with the obsoleting of NTSC tv signals). There is an external trigger input on the back panel, selectable with the front-panel trigger source switch. The unit has an X-Y mode where channel 1 is the X axis and channel 2 is the Y axis. This is mode is used to display the output of devices such as curve tracers. An example display is in one of the panels of the screen composite photo. This is the "G" model with the built-in function generator, which generates sine, square and triangle waves from 0.1 Hz to 1 MHz. The function generator output has an offset capability but no symmetry control. Sine wave distortion is specified as less than 2%. The last photo shows the spectrum of a 1 KHz sine wave, with harmonics at least 50dB down from the fundamental, so the distortion spec is easily met. There is a back-panel TTL-level square wave from the function generator. When I had this scope on my bench, I found it convenient to feed this output to a frequency counter, so I could get a continuous readout of the frequency. Three of the images in the composite photo show the generator output on one channel and the TTL output on the other. In addition to the back-panel function generator output and external sync input, there is a channel 1 output. This is approximately 60 millivolts per division of channel 1 deflection. This could be fed back into channel 2 to give a sensitivity in the microvolt range, but with much reduced bandwidth. The channel 1 output is AC-coupled and shows a low-frequency roll-off as evidenced by the tilt in the lower trace in the last photograph. The channel 1 input is a 200Hz square wave. The original operation manual is included.A power cord with a right-angle connector is included. The right angle is essential when using the 'scope set on its back feet. A BNC-to-alligator clip cable is included. This was presumably to be used for function generator output, but could be used for other inputs. No probes are provided, but the inputs are standard 1 megohm, so the low-cost 10X probes available from numerous sellers on eBay are compatible.

Condition	Used : An item that has been used previously. The item may have some signs of cosmetic wear, but is fully operational and functions as intended. This item may be a floor model or store return that has been used. See the seller’s listing for full details and description of any imperfections.
Seller Notes	“Excellent cosmetic condition, excellent working condition.”