After installing the new 12X4 rectifier tube and powered up, the tube started arcing inside and there was a blue glow. I thought that the tube was bad so I had my tube supplier send another new tube. Same problem but this time the solid state vibrator died. So I decided to try a different vibrator from Aurora Design. This new vibrator is one bullet proof awesome chunk of engineering!! Installed it and everything works great!!
I came up with a suitable solution for the speaker replacement. The original speaker was designed to fit into a very shallow box. This speaker is not made anymore and there is not direct replacement for it. I also could not find anyone who would recone it either. So I looked for another solution. I came up with mounting to small round speakers in the same space as the 4" x 6" speaker using a adapter plate I made.
Original 4" x 6" speaker mounted with #8-32 weld in studs
Cardboard template to make an adapter plate from
Template transferred to sheet metal
Sheet metal cut out
Sheet metal mounting holes drilled and trimmed
One of the two speakers
Sheet metal marked for the speakers
Pilot hole for the jig saw
Speaker holes cut out
Speakers test fitted on the sheet metal adapter plate.
I used #4-40 flat head brass screws
Test fit into the enclosure
Adapter plate painted flat black and speakers mounted
I added some strip caulk to help reduce metal to metal vibration
All mounted and wired with strain relief. I also made a plug for the speaker to radio interface.