[Tucker]

This cabinet has an opening on the bottom that looks like it was put there at the factory. Just wondering what the purpose of this opening is? This is the only radio that I’ve seen with this cutout.

[morzh]

Picture always helps.

[Tucker]

    .  Here’s a picture of the bottom.

[morzh]

Don't know factory or not, but it looks like a removable cover/plug and seems to give access to the RF chassis' adjustment parts (trimmers etc), so this is probably what it is. It then should be replaced after the alignment.

[Jake Blake]

This cabinet has an opening on the bottom that looks like it was put there at the factory. Just wondering what the purpose of this opening is? This is the only radio that I’ve seen with this cutout.

I'm not sure about this, but my guess is , since this model has such an involved array of switching, it could be for easy cleaning of those switch contacts.
Cool radio.  

[Ron Ramirez]

I've never seen an opening like that on a Big Bullet. Pardon me for being skeptical, but it appears one could not get to all of the adjustments with that opening (some hidden toward the front)?

[morzh]

Yes. But it appears well made. Even factory made.
Maybe a prototype.....???