[Guest]

I just recapped and replace 2 bad tubes in my 38-7. I'm getting good reception in the 1300-1500 range on multiple stations, but when I move the dial below about 950 I get nothing, not even pops or static. Is this an alignment problem? I was told on another forum that it was possibly a short in the variable cap, but I'm not sure what to look for or how to fix the problem. I don't have a signal generator to align with either. Thanks for any help!
Mike

[Guest]

Found the short, works good now. Still not nearly as good of reception on the lower half of the dial though.

Mike

[Ron Ramirez]

Mike

Have you aligned your radio to factory specs?

The low end AM alignment is very critical to good performance not only of the lower end of the AM band, but to the overall performance of the radio.

When aligning the low end AM trimmer, typically at 600 kc (although it is sometimes 580 kc in certain Philco models), the thing to remember is that you are NOT aligning so that the pointer points to exactly 60 on the dial!

Instead, you want to tune in the 600 kc signal on your radio. Then slowly adjust the trimmer. After adjusting the trimmer just a fraction, retune the radio, following the signal. If the signal becomes weaker, turn the trimmer in the opposite direction; again, just a fraction. Then, once again, retune the radio to the signal.

Repeat this process until you can not get the signal to get any stronger. When it begins to weaken again, stop and retrim to its strongest point.

This procedure is known as "rocking" the tuning condenser.

This ensures that the proper intermediate frequency (IF) signal is being sent to the IF circuitry, and thus is more important for that than for whether the set is exactly at 60 on the dial or not.