The PHILCO Phorum

I have 3 model 90 radios, 1 is fully restored, didnt come with the original mounting cardboard, but has some aluminum looking plate, 2nd one is my dual 45 tube 90 that I purchased a bare bones cabinet for, so yet again no original mounting cardboard to go from. 3rd philco 90 from ebay yet again not original speaker and (from another type radio backer). Id like to install the speaker in my cabinet but no clue how the speaker is attatched to the backer or how the backer is attatched to the cabinet. I really dont want to take apart my good canadian restored 90 just to see how they did it, while the front of it looks good, I cant tell how they attached the backer. Been searching sites and youtube and nothing to show how it goes together. Im not even to sure how thick the cardboard has to be or the screws used as mine are all hacked in.

I am not even sure it is cardboard.

I've had to make a couple of them and I used some old 3 ring binders and cut the covers off.
That left me with 2 hard boards that I cut to fit. I did have an old one to use as a template.
 Some guys buy some type of picture frame backer and use it.

The foam board (sold in hobby stores) works fine and is easily cut.

found a thread on here that said art frame shops sell matting, picked up that for pennies. Installed. it isnt perfect round on bottom sides of tuning window but it works. I installed philips screws for the speaker with the heads ground off. I didnt know the front of the radio cabinet unscrewed. There are 3 big round cutouts or insets like theres supposed to be a washer. I just used screws hopefully thats enough to hold the speaker