Jack — if I understand your questions correctly:

1. Fender traditionally designed Input 1 to be about 6 dB hotter than Input 2. This design came before active pickups were common, and the idea was to give players flexibility depending on the output level of their instrument — whether it was a guitar, bass, microphone, or even an accordion back in the day. A modern application would be to use Input 1 for a standard single-coil Fender-style guitar and Input 2 for a hotter humbucker-equipped instrument.
2. You can use an A/B box to switch between the two channels without any problem, but you can’t “jumper” the channels together like you can on old Tweed amps — doing so will cause an unpleasant out-of-phase sound.
3. Picking up radio signals occasionally is not unheard of and doesn’t necessarily indicate a defect in the amp.

Enjoy your Deluxe — it’s a great amp!

Try using a different instrument cable (i.e. from guitar to amp). Cables are basically giant antennas if they aren’t completely shielded, so it pays to use good quality cables.

I’ve got a couple of questions about my 2014 ’65 Reissue Deluxe Reverb: 1) The jack inputs on each channel are rated at 1M ohms for Input 1 and 136k ohms for Input 2 (I think) — what’s the advantage of this? Is it designed for active vs. passive pickups? 2) Can I use both channels at once with the “Y” output of an AB/Y pedal without damaging anything? 3) Lastly, does anyone else pick up radio stations through their Deluxe Reverb? I traded my ’68 Custom Vibrolux Reverb (plus some cash) for this one because I preferred the deeper reverb and earlier tube breakup compared to the cleaner tone and weaker reverb of the Vibrolux. But I immediately noticed radio interference once I set it up in the same rack space. I’ve tried running it through a Furman power conditioner and a Radial passive box with lift, phase, and ground loop switches — nothing helps. The interference only comes through when the effects (reverb and tremolo) are engaged. Any ideas? Thanks for your help, —Chris