If you want to build an amplifier using a tetrode but don't want to mess around with screen and grid powersupplies this one is for you!
HV and filament voltage required, just as in a grounded grid amplifier. Screen voltage is derived from the input RF and the grid is at DC ground.
Check the circuit description below.
Top of the rack is a small homebrew 4CX350A amp for 144 MHz, below that is my homebrew HF amp described below.
Check some detailed pictures, circuit diagram and tube specs
| Anode compartment | Anode plus tank circuit switchable 160-10 mtrs |
| Anode compartment 1 | Anode plus tank circuit, side panel view |
| Anode compartment 2 | Anode plus tank circuit, top view |
| Bottom view | Input circuit, relay pwr supply, screen bypass |
| Screen bypass 1 | Screen (g2) PTFE sandwich bypass, close view |
| Input | Input PI-network, relays switch different bands |
| Input 1 | Input PI-network plus input resistors |
| Schematic diagram | G2DAF style QBL 5-3500 schematic diagram |
| Input circuit, coils | Schematic of input circuit using 9mm dia coils with trimmer cores |
| T/R switching | T/R switching using RJ-1A relays |
| QBL 5-3500 specification sheet | PDF with all tube data. (1Mb) |
