03-07-2015, 09:11 PM
To be a bit more precise the 84 is a 4 tube superhet with a regenerative detector. Mike is right about the alignment, Don't try to a just any of the trimmer condensers without any signal generator. Except for the one all the way to the left side on the rear apron. It has a brown phonolnic slotted nut. It's the regeneration control.
Unplug the set turn it on with the volume full up. Use an ohm meter and measure between the ant post and chassis ground. If all is well you should only see 5 ohms or less. If it is higher your ant coil has an open primary. Do the same by measuring the resistance from chassis ground to the junction of parts 6&7 at the connect on the oscillator coil. Again should show a few ohms. Guess what if not the feedback winding ( sometimes call tickler winding) is bad. Its very common for these coils to be bad. No worries as they can be fixed easily.
The next issue is the resistors. If you measure them you will find that most have drifted badly. #8,12,18,19,&22 are suspect give them the hairy eyeball.
Assuming that the caps have been replaced that should put you in good shape.
Have fun!!!!
Terry N3GTE
Unplug the set turn it on with the volume full up. Use an ohm meter and measure between the ant post and chassis ground. If all is well you should only see 5 ohms or less. If it is higher your ant coil has an open primary. Do the same by measuring the resistance from chassis ground to the junction of parts 6&7 at the connect on the oscillator coil. Again should show a few ohms. Guess what if not the feedback winding ( sometimes call tickler winding) is bad. Its very common for these coils to be bad. No worries as they can be fixed easily.
The next issue is the resistors. If you measure them you will find that most have drifted badly. #8,12,18,19,&22 are suspect give them the hairy eyeball.
Assuming that the caps have been replaced that should put you in good shape.
Have fun!!!!
Terry N3GTE
