[Mondial]

Eric, don't expect a lot of performance out of that radio. Its a primitive circuit and a cheap implementation of it at that. Be happy that it works at all. If you don't have powerful local stations, you really won't hear much without a long antenna.

As far as the 2.5 Meg resistor, that's the grid leak for the detector tube and its about the right value. The Atwater Kent model 40 has a similar circuit and uses a 2 Meg resistor in the 27 grid circuit. A higher resistance actually makes the receiver more sensitive. The tube data you saw was probably for using the 27 as an amplifier not a detector, so the 1 Meg max resistance does not apply here.

Glad you got it working after all the work!