About
Reviews (4)
01 Jun, 2017
Works as well as you would expect
1 of 1 found this helpful Used these tablets in Cuba in May when there were many mosquitoes stinging. We did get one or two in the room when entering and leaving but both those I saw were struggling to get out - away from the tablets!
They were effective in a plug-in heater and the smell is actually quite pleasant.
I think they are best used within a year at most as the old ones we used up at Christmas didn't dissuade mosquitoes from flying in our bedroom.
Overall - an excellent buy and very effective
13 Apr, 2017
Simply the best
As a cellist and six-string electric guitar for thirty years I had flat wound steel strings and found them to hold pitch and very smooth to use. A change of direction sent me to the electric bass and my natural choice was these Rotosound strings. I was not disappointed. Worth every penny
24 Apr, 2020
Good base for a function generator after some modifications
1 of 1 found this helpful The kit of parts is OK on the surface. If you check the circuit and components against the original manufacturer's data sheet, several of the components in this kit are of the wrong values. This leads to instability and poor control of settings.
One problem is that the XR2206 Integrated circuit is not a genuine Exar chip but a copy. This can be put right in two ways
1) Buy a genuine XR2206 chip (approx £15)
2) Change component values as supplied to get the performance to a reasonable standard
If you build it with some knowledge of electronics, you can use the kit as a base and what I suggest is not fitting any of the adjustment potentiometers to the PCB, but buy a small instrument case and mount the correct value of controls on the front panel.
Change several components to the suggested values in the Exar data sheet including fitting one or two trimmer variable resistors instead of fixed resistors to adjust distortion of the sine wave output.
On the Square wave output, there is a pull-up resistor of 1k ohms and this is recommended at 10k ohms on the Exar data sheet. Worth doing to cut the high current from this output into any equipment you may want to test as the high current can cause severe damage to, for instance, an audio amplifier.
Also worth putting a small value electrolytic capacitor in series with the square wave output as this removes the high DC voltage offset in that signal, leaving you with a clean square wave around 0v.
I will assemble with a rotary control instead of jumpers to change frequency ranges and a switch to change from sine to triangle wave instead of that jumper.
With a few changes like this, the kit has a useful basis for a home-build function generator.