[MrFixr55]

Hi Griff. Interesting that you get nothing when touching the 77 (a pentode). Yes, this is a bit newer than the original which used a 36 (a tetrode). A 6A7 Pentagrid converter is the best iteration but did not come on these radios.

The fact that you do not get any sound when touching the 77 grid cap makes me think that the "oscillator" coil on the converter transformer is open. This coil has 3 windings. 2 are on the outer core and one is on the inner core. The small outer winding is the oscillator coil and is between the cathode of the 77 and a resistor with parallel cap, the other end being ground. Ohm between the cathode and the connection between the coil, cap and resistor (this will ensure the correct points). There should be a very low resistance, between 1.5 and 5 Ohm. Alternately, with the set out of the chassis but the speaker connected, measure between ground and the 77 cathode. This should be a low voltage. if it is a high voltage, the coil or the resistor is open (more likely the coil) and you will find instructions on rewinding the coil.

Search the Philco Library for "89 coil" and search the Phorum for 89 Oscillator coil or 89 Tickler coil. Ron Ramirez and RadioRoslyn are experts on this issue.

The Autodyne 1st Detector is very cantankerous, particularly in the 89. However, the ones with the 77 are less trouble than the 36. However, follow the advice to bake the coil (and check the insulating enamel on the secondary) before rewinding, and then seal the entire assembly with clear lacquer.