I've just posted a new page on my website which, like my page on Philco Model 60 sets, traces the evolution of the Model 89.
If you have ever worked on a Philco Model 89, or are contemplating doing so in the future, you need to see this new page on my website. Here, I have incorporated ALL of the documented changes (and a few undocumented ones) to Model 89. I also made modified schematics showing these changes, which resulted in ten different schematics!
You should find this page to be very beneficial to you if you own or work on a Model 89 set.
http://www.philcoradio.com/tech/89evol.htm
The page has a lot of images, so please allow time for these images to load if you have a slow internet connection.
If you have ever worked on a Philco Model 89, or are contemplating doing so in the future, you need to see this new page on my website. Here, I have incorporated ALL of the documented changes (and a few undocumented ones) to Model 89. I also made modified schematics showing these changes, which resulted in ten different schematics!
You should find this page to be very beneficial to you if you own or work on a Model 89 set.
http://www.philcoradio.com/tech/89evol.htm
The page has a lot of images, so please allow time for these images to load if you have a slow internet connection.