[462ron]

I don’t know exactly how dim your pilot gets but this is the typical of the response of many transformerless AA5s where the bulb, usually a #47, is in series with the filament string and across a portion of the rectifier filament and plate of the rectifier. When first switched on, the filaments are cold, thus at a low resistance for a bit. The bulb flares up bright but then dims down as the filaments heat up and increase in resistance. Then the tubes start to conduct and draw current through the rectifier and the bulb so the brightness comes up slowly. From what I’ve seen, it doesn’t get as bright as it does when first switched on and filaments are cold.

Ron