Elenco Model FG-500 Function Generator
1.0
This inexpensive device produces the choice of three different waveforms; Sine, Triangle, and Square Wave, in a switch-selectable range from 10 HZ to 1 MHZ in 6 separate ranges (10, 100, 1K, 10K, 100K, 1M), and at an adjustable amplitude varying from
0 to 6 volts Peak to Peak depending on frequency and type of waveform on my unit. Output is via banana jacks; Triangle or Sine are selected via a slide switch and sourced through one jack, Square are sourced separately through another, and the third jack is common ground. A slide switch powers the unit on and off. The housing is non-shielded plastic or Bakelite; dimensions are 6" long x 3-3/4" wide by 2" high.
The unit is available in kit form or as a completed unit; as I have built many kits and am familiar with them I decided to go that route. Construction is good; parts placement is well laid out and the instructions are clear and understandable. One step I performed that the manual does not talk about is to use a flux remover on the PC board after all soldering. Which I would always recommend in oscillator circuits. The device utilizes a XR-2206 monolithic function generator integrated circuit, consisting of 4 main functional blocks. These are the voltage controlled oscillator (VCO), an analog multiplexer and Sine-wave shaper, a unity gain buffer amplifier, and a set of current switches.
Operationally, this unit has severe deficiencies and I recommend not wasting your money. Waveform symmetry is terrible for all three types of waveforms as seen on my scope using a 50-ohm load. There is lots of signal bounce, as well as overshoot and undershoot. Waveform symmetry of Square waves approaches that of Triangle waves in the middle ranges of the selector switch. Symmetry can be corrected somewhat with the amplitude control for Square Waves in Sine and Triangle mode, but interestingly enough the amplitude control does not appear to control amplitude for Square Waves; only for Sine and Triangle. With careful tweaking I can get waveforms that approach usable Sine and Triangle in the middle frequency selector switch ranges. Square wave is nothing approaching a good square wave, with ripple in the middle of the pulse plus overshoot and undershoot at the pulse edges.
An interesting kit to build, but not worth your money.
Verified Purchase
John Moorhead on
Apr 02, 2022
I found this helpful
(0)
All product Reviews