03-05-2016, 11:38 PM
Yup, Mike, piece of mind thing.
This afternoon and evening, I performed the hardest part of this job - replacement of the lamp which illuminates the dial pointer.
To do this, you have to remove the front panel, and then remove the plastic dial following the procedure shown here at AudioKarma.
And then the metal part which is behind the front panel needs to come off.
You have to be careful after removing this, as the dial string can easily come loose now since the tuning shaft is now floating unattached.
After taking the front of the receiver basically all apart, it looks like this:
[Image: http://www.philcoradio.com/images/phorum..._00017.jpg]
Now, by carefully lifting up the assembly which holds the dial lamps, the dial pointer can be carefully removed from the dial string. Here's how it looks:
[Image: http://www.philcoradio.com/images/phorum..._00018.jpg]
The dial lamp is held inside the assembly. You have to carefully un-bend two tabs and then the lamp itself is revealed.
[Image: http://www.philcoradio.com/images/phorum..._00019.jpg]
[Image: http://www.philcoradio.com/images/phorum..._00020.jpg]
As it turned out, the original incandescent lamp is much larger than a 2mm LED. In fact, a 5mm LED will easily fit here. I just happened to have a couple 5mm white LEDs on hand.
[Image: http://www.philcoradio.com/images/phorum..._00021.jpg]
I carefully went over an LED with sandpaper to make the bulb more opaque so that it would diffuse the light better.
Taking careful measurements with my DMM, I determined which wire connected to ground and which one didn't. The one which did not was connected to the LED's anode; the grounded lead to the LED's cathode.
I then reassembled the dial pointer and reattached it to the dial string.
[Image: http://www.philcoradio.com/images/phorum..._00022.jpg]
The anode lead is not connected directly to the 8 volt AC source - it connects through a silicon diode.
[Image: http://www.philcoradio.com/images/phorum..._00026.jpg]
The cathode lead does not go directly to chassis ground - it is shunted through a 390 ohm resistor.
[Image: http://www.philcoradio.com/images/phorum..._00027.jpg]
This afternoon and evening, I performed the hardest part of this job - replacement of the lamp which illuminates the dial pointer.
To do this, you have to remove the front panel, and then remove the plastic dial following the procedure shown here at AudioKarma.
And then the metal part which is behind the front panel needs to come off.
You have to be careful after removing this, as the dial string can easily come loose now since the tuning shaft is now floating unattached.
After taking the front of the receiver basically all apart, it looks like this:
[Image: http://www.philcoradio.com/images/phorum..._00017.jpg]
Now, by carefully lifting up the assembly which holds the dial lamps, the dial pointer can be carefully removed from the dial string. Here's how it looks:
[Image: http://www.philcoradio.com/images/phorum..._00018.jpg]
The dial lamp is held inside the assembly. You have to carefully un-bend two tabs and then the lamp itself is revealed.
[Image: http://www.philcoradio.com/images/phorum..._00019.jpg]
[Image: http://www.philcoradio.com/images/phorum..._00020.jpg]
As it turned out, the original incandescent lamp is much larger than a 2mm LED. In fact, a 5mm LED will easily fit here. I just happened to have a couple 5mm white LEDs on hand.
[Image: http://www.philcoradio.com/images/phorum..._00021.jpg]
I carefully went over an LED with sandpaper to make the bulb more opaque so that it would diffuse the light better.
Taking careful measurements with my DMM, I determined which wire connected to ground and which one didn't. The one which did not was connected to the LED's anode; the grounded lead to the LED's cathode.
I then reassembled the dial pointer and reattached it to the dial string.
[Image: http://www.philcoradio.com/images/phorum..._00022.jpg]
The anode lead is not connected directly to the 8 volt AC source - it connects through a silicon diode.
[Image: http://www.philcoradio.com/images/phorum..._00026.jpg]
The cathode lead does not go directly to chassis ground - it is shunted through a 390 ohm resistor.
[Image: http://www.philcoradio.com/images/phorum..._00027.jpg]
--
Ron Ramirez
Ferdinand IN