[Tubesforme]

> I can move the 640 station on the dial up or down, slightly, using the #7 600 Khz trimmer.

I would think you should be able to move it 100kc or better. Not quite sure how much slightly is?
If you have a scope you can look at the osc output at the grid cap of the 24A mixer. Check the amplitude.
I think you'll find it's dropping off as you get lower in frequency

Additional notes. I found that we have stations located at 570, 610, 640, 670, 710 and up. I can't receive either 570 or 610. From 640 up, everything seems to work. I did discover that adjustment #7, the 600 Khz trimmer doesn't seem to move the frequency as much as I thought it did. I adjusted it while rocking the dial. 640 has lower volume than any other of the stations. 710 works, but the volume must be raised considerably. All stations from there on up are very loud. I don't have a scope. I wasn't able to move the station located at 640 more than 10 Khz either way from its frequency. For both 640 and 710 the volume must be turned up well over half way. On any other station that level of volume will drive you out of the room. The only equipment I have is a DMM, VTVM, signal generator, signal tracer, variable AC isolated supply and tube tester. The signal generator is only one year old. I did not connect a capacitor in series with the generator lead as the Philco instructions call for. The generator instructions call for use of a resistor from 100 to 200 ohm in series with the hot lead. I did not use a resistor this time, when adjusting the trimmer.