Sencore Mighty Mite chart data EAF801

Simon Flint from Australia contacted me today because he noticed that the Sencore Mighty Mite setup data for the diode section in tube EAF801 (which is an RF Pentode with Diode section) did not appear to be testing the diode section properly.  He wanted to know if I could investigate.

I examined the Telefunken datasheet for EAF801 and have determined that the Sencore setup data for this diode section of the tube is wrong.  It places far too much load on the diode, causing the meter to incorrectly read low emission.

The EAF801 diode section is only rated at 0.7ma according to the Telefunken datasheet, therefore the chart setting (D load) will draw far more current than the EAF801 diode can handle.  In fact, extended testing using this incorrect chart data will ruin this diode section.

My analysis suggested that Load G is the correct load for the EAF801 diode section.  Simon tested this load, and has verified that my analysis is correct.  Thanks to Simon for diligently testing the new load setting and verifying that it is now correct.

So for the diode section (only) for EAF801, the load should be G…not E.  Make a notation in your chart to reflect correct load (the 2nd line of the setup data for EAF801).  Purchases of my TubeSound Sencore mighty mite setup book will have this factory mistake corrected if purchased after March 12, 2021, and the correction will “look factory”.