70MHz 4CX250B Amplifier

It had been twenty years since I build a tetrode amp. I found three of these valves literally rolling around in my carboard junk box, and wondered whether they still worked. So it was a 4m amp for the 2013 summer project - not that I need another amp for this band, this was just to pass time.
In keeping with my liking for all things 19", this amp was built into a 3U cabinet, with blower on the rear panel.

Anode circuitry is a simple pi network, using 5mm dia solid copper for the L. A silver plated cavity isn't needed, but it's what I had available and is a good fit for the components and the cabinet.
Grid volts barely reached cut off due to the transformer's 70V secondary, so the screen is also grounded on receive.
Front panel switching is for blower and the lower switch powers the screen/grid/switching transformers. Meters for screen current with zero offset, and power out. LEDs for TX and Grid current.
Rear panel is fitted with N types, spaced to fit a CX-520 relay, and more N types to feed drive in and Rx out. Phonos for PTT in, DC out to power the CX520 and one spare socket. HV goes in on C-type.

Results
With 2.2kV on the anode, a few watts of drive drive gives an easy 200W out.

Conclusion
These days most people would use a FET for this power level. But why not remember how it was done during the 'old days'?