03-23-2016, 06:30 PM
Might be a bit easier to use a signal generator to go though the IF stage to check the IF, det, and audio. Do this by inserting a 470kc modulated signal down the grid cap of the 6A8.
You can listen for the LO at 470kc above the dial setting on the '670 with a transistor radio near the 6A8 tube.
If all that checks out ok hook your ant to the cap of the 6A8 mixer tube. Should hear stations if all is working except for the RF amp. Hook ant the the ant connection if rf amp is working you'll hear stations.
I feel for you bro I've got a 37-675 and it's a pita to work on. Mine has a bad rf amp coil or a bad band sw. Plays good if I hook the ant to the mixer cap, rf amp is dead. Hopefully it's something simple!!
Terry
You can listen for the LO at 470kc above the dial setting on the '670 with a transistor radio near the 6A8 tube.
If all that checks out ok hook your ant to the cap of the 6A8 mixer tube. Should hear stations if all is working except for the RF amp. Hook ant the the ant connection if rf amp is working you'll hear stations.
I feel for you bro I've got a 37-675 and it's a pita to work on. Mine has a bad rf amp coil or a bad band sw. Plays good if I hook the ant to the mixer cap, rf amp is dead. Hopefully it's something simple!!
Terry
