Generally , I don't realign sets that seem to be "OK" but lately I have discovered that a partial alignment can do wonders for a set that has had a complete re-capping. I have gone back to a couple of AM-FM- shortwave sets that I recapped 3 years ago but was reluctant to do any alignment because the service data was in German and Dutch. I know more about these sets now and, working backwards from the last IF, adjusted just the If transformers to get the best sound for the AM and FM bands. It improved the sensitivity remarkably. They didn't need much turning but the result was very pleasing. For FM I did not touch the secondary coil for the ratio discriminator, just the primary. I did not adjust any of the other trimmers or padders. In addition, I did not need to use my signal generator. I just tuned to a weak station on each band and did the adjusments. A couple of the iron cores were frozen, so I needed to unfreeze them. I used a hair dryer to warm them up and this loosened them up nicely and they stayed loose even after cooling off. I hope this helps anyone who feels intimidated by a radio they don't know much about.

That is pretty much the procedure I use. If a radio is un-molested the alignment is A) probably not 100%, and B) not off by much.

A little tweaking does wonders sometimes.

In the late '50s and early '60s, when I worked for a shop that serviced many German AM-FM radios, we used a similar procedure, with the following differences:

The FM was tuned to an empty spot near the high end of the dial. the volume was raised to where you could hear the inter-station hiss. The secondary of the detector transformer was de-tuned slightly, to increase the hiss. Working backwards through the IFs, tune for maximum hiss. Re-tune the secondary of the detector for minimum hiss and you are finished.

Thats a good tip Brian. I'll try that next time.

Good subject! That being said, it is VERY easy to break composite Ferrite adjustable cores in IF cans! (don't ask me how I know). If either one breaks, resonance will stop:( Better to try to loosen them up as suggested and try turning with a plastic tweaker. If that doesn't work, then leave them alone-sometimes the mark of a competent technician is knowing when to stop. My .02:)-Gearhead.

Amen to that! Sometimes the most valuable lessons are the hardest-earned.

I was once told that experience is what you get the moment after you needed it. I've broken too many of those IF slugs to be interested in forcing them anymore. If they don't move easily with the plastic tool, they stay put. I've got an old Japanese-built tube CB that has most of the ferrite slugs cracked. Not all of them were me, but at least one is. Thats going to be a real treat. Once I get them out, then I have to figure out replacements.

THose German radios-when I look at the schematics, I get dizzy. Have not tried alignment on one yet, due to insufficient data on what is where and how, etc.

If and when I get a radio going, I perform an exploratory inspection to see if an alignment can reasonably be attempted toward a betterment in reception. I'll leave the compicated European sets to my betters.

I've never met a post-war German radio that hasn't benefited from a proper instrument alignment.

It's part of the learning curve. Some promote it, some rationalize against it, some won't admit it..
I personally consider it part of the fun and satisfaction to make the radio perform its best.

Can you use a "diddle stick" (ferrite on one end, brass on the other) to check IF transformers?

Agreed that almost every old receiver could benefit from an RF/IF alignment, and actually even if never recapped, simply because the majority of components have proven themselves to drift in their values over the decades.

That said, it would have to be understood that most hobbyists don't own a sweep-marker spectrum analyzer, and although using such an instrument could very likely achieve the pinnacle of perfection, that peak would be relevant in only a small percentage of listening exploits for most AM radio users, generally involving DXing very weak signals.

I think for the majority who restore old sets just for themselves, peaking by ear using either a weak AM station or a signal generator tone, provides a sufficiently acceptable alignment process.

I saved that FM alignment. thanks to Brian