In between ordering this Function Generator and it arriving from China, I happened across a Youtube (https://www.youtube.com/watch?v=FaNvHQW_CsQ), in which Steve pointed out a couple of issues with the unit.
The Earth to ground lead needs better isolation and the glass fuse should be ceramic.
Also mention was that the unit can run hot. I spotted the main board has a underpopulated fan connection and the back panel has a mounting port for a 40mm fan.
I measured the fan output at 5V DC, so I will order a fan.
I stripped out some earth wire from a 2.5mm cable but the inner diameter was too tight to slip over the existing wire. I have no sleeving or heat shrink, so maybe I should get some.
Giving up on this a recalled a I some connector kits so I decided to replace the wire. My kits have some male and female crimp connectors. I discovered that the female connectors supplied do not even fit in the header that is supplied in the box. They are all designed to be used with smaller cables then the 0.75mm I had stripped from some mains flex too.
Until I can get a suitable crimp for the connector and hopefully one that will take the cable. I have paired down half of the wire strands and crimped the remaining strands into a connector. I have used the strain relief section as an extra crimp onto the copper wires as the mains insulation is way too big for the connectors strain relief to cope with.
As I had desoldered the ground wire from the IEC socket I installed the new Earth wire with a spade connector. It is likely I will be inside the unit again so the ability to unplug the back plate seemed logical. I spent ages looking for a back full of the spade connectors, but they seem to have vanished. I must get more ordered.
I could not read the value of the glass fuse so I desoldered it. It is marked 2AL 250V. Ceramic 10mm fuses with wires are available in Fast and Slow Blow versions. Before I order them I must decide if I am going to replace the existing supply or not.
Steve designed a complete power supply but this came in a a hefty price and was largely surface mount. I am not really equipped for or experience in working with SMD.
The other suggested cheaper option was to use a couple of modules available form china. The issue here is that apparently I would need to design some filter to remove the noise. It would be worth pursuing if there is a compelling reason to remove the existing supply, but if all that’s wrong with PSU board is the glass fuse then it would be a lot simpler to just order a ceramic fuse for it.
I will have to watch the video a bit more to try and work out why Steve went to such trouble and expense upgrading this otherwise bargain basement function generator.