I recently bought an Atwater Kent model 70,with an L chassis.The tubes in it are 3 24A's,2 45's,227's and an 80.The problem is,where the 3 24A's are in a row,in the 4th tube slot where the 27 is.On the plate it say's a27 tube goes there but there is a grid wire to go on a grid cap like the 24A's.Reading about another L chassis,the tube layout on it had a 24A in place of the 27,putting 4 24A's in a row.Please let me know if it is a 24A or a 27 tube like the tube plate say's.Would appreciate any help,thanks ,Ira.

Hi,
There were two production versions of the "L" chassis. Both use the same tube complement what is presently in yours, 1-80, 2-45, 3-24A, 2-27.

From your description, you have a chassis that someone may have modified to accept another 24A- Or worse, something else entirely.

I wonder if it is not the same handiwork as the fellow who butchered my H chassis and put in a 2A6 where a 24A had been?

Schematic and underchassis views are here:

http://ww3.nostalgiaair.org/schematics/A-K/_A-K_1-40.gif
http://ww3.nostalgiaair.org/schematics/A-K/_A-K_1-39.gif
For the early.
For the late:
http://ww3.nostalgiaair.org/schematics/A-K/A-K_3-52.gif
http://ww3.nostalgiaair.org/schematics/A-K/A-K_3-51.gif
http://ww3.nostalgiaair.org/schematics/A-K/A-K_3-50.gif

Your repair should be easier than mine was. You just have to relocate up to 3 wires, and make sure the dropping resistor for the 27's is in place.

:I recently bought an Atwater Kent model 70,with an L chassis.The tubes in it are 3 24A's,2 45's,227's and an 80.The problem is,where the 3 24A's are in a row,in the 4th tube slot where the 27 is.On the plate it say's a27 tube goes there but there is a grid wire to go on a grid cap like the 24A's.Reading about another L chassis,the tube layout on it had a 24A in place of the 27,putting 4 24A's in a row.Please let me know if it is a 24A or a 27 tube like the tube plate say's.Would appreciate any help,thanks ,Ira.