Rerurn to Romy the Cat's Site
In the Forum: Melquiades Amplifier
In the Thread: Planning my DSET
Post Subject: In my dreamsPosted by anthony on: 1/3/2019
I woke up this morning to have the brightest thought that my DHT issues are probably caused by how I have wired up the filament transformers. When I ordered all the transformers for this project I gave Lucas of Black Art Automation the design brief 'build the best you can'...that's kind of like signing a blank cheque...but we talked about building tight regulation transformers on big cores with minimal heat gain et cetera, and one of the things that he did was make individual 2.5V and 4V transformers for the DHT filaments.
There's nothing wrong with that of course but they are also centre-tapped, which I was not expecting. I have brought the centre-tap into the amplifier chassis and bonded it to the chassis ground, which I am thinking is not allowing it to float to make the 184V reading at the DHT Cathode: it stays firmly planted at 0V when the DHT is getting too hot.
I hope that is the issue because I would also like a couple of extra wires in the filament cable so that the 12.6V filament supply can be parallel wired to offset a larger than expected voltage drop.Rerurn to Romy the Cat's Site