06-08-2019, 08:36 PM
So in our last installment, as you recall...I accomplished everything listed in post #39 above.
Here are a couple photos.
[Image: https://philcoradio.com/images/phorum/70mod/70_020.jpg]
The under-chassis view after I had done everything listed in post #39. All components having to do with the old power detector circuit have been removed. Also, an old 500K potentiometer from a long-dead 96 or 112 has been installed in place of the former dual volume control.
You'll notice that the added 270 ohm resistor for the cathodes of most of the 35 tubes and the 27 tube (seen in upper right of the photo above) is a 5 watt unit. I know this is overkill, but I had several so I used one instead of buying a 1 watter just for this project.
[Image: https://philcoradio.com/images/phorum/70mod/70_021.jpg]
A close-up of the two IF transformers, showing how I unsoldered each of the lower secondary terminals from their respective mounting brackets, and bent them upward. You will also note that each IF transformer has been physically rotated counterclockwise just enough to keep the lower secondary terminals from touching the mounting brackets. As you recall, this was accomplished by loosening the center bolt where the transformer is mounted to the mounting bracket, carefully rotating the transformer itself, then retightening the bolt.
In my next post I'll talk a little about what I did to this 70 today (not much actually), and then I'll have another question for Ed.
Here are a couple photos.
[Image: https://philcoradio.com/images/phorum/70mod/70_020.jpg]
The under-chassis view after I had done everything listed in post #39. All components having to do with the old power detector circuit have been removed. Also, an old 500K potentiometer from a long-dead 96 or 112 has been installed in place of the former dual volume control.
You'll notice that the added 270 ohm resistor for the cathodes of most of the 35 tubes and the 27 tube (seen in upper right of the photo above) is a 5 watt unit. I know this is overkill, but I had several so I used one instead of buying a 1 watter just for this project.
[Image: https://philcoradio.com/images/phorum/70mod/70_021.jpg]
A close-up of the two IF transformers, showing how I unsoldered each of the lower secondary terminals from their respective mounting brackets, and bent them upward. You will also note that each IF transformer has been physically rotated counterclockwise just enough to keep the lower secondary terminals from touching the mounting brackets. As you recall, this was accomplished by loosening the center bolt where the transformer is mounted to the mounting bracket, carefully rotating the transformer itself, then retightening the bolt.
In my next post I'll talk a little about what I did to this 70 today (not much actually), and then I'll have another question for Ed.
--
Ron Ramirez
Ferdinand IN
