11-25-2014, 11:33 AM
...to paraphrase an old hit song...
What A Diff'rence An Alignment Makes...
[Image: http://www.philcoradio.com/images/phorum...e00013.jpg]
Philco apparently expected the service man to align the set inside the cabinet. But there is a problem with that - when in the cabinet, it is difficult if not impossible to reach all of the adjustment screws.
So I improvised - I took a photo of the front of the radio, focusing on the dial scale. Then, using Paint Shop Pro, I made a negative image of the scale, printed it, and temporarily taped it to the dial back plate for alignment purposes. This really made performing the alignment much easier.
The alignment was way off. Once the IF transformers were adjusted back to the proper 455 kc frequency, the AM band was then way, way off. A local station (WITZ, 990 kc) was coming in around 650. I could no longer hear my SSTRAN which is set at 660.
But once I went through the entire procedure, I not only managed to get the AM band more or less back on track (pun intended), the problems I initially experienced with very broad tuning at 660 and oscillation from 670 to about 750 kc disappeared. All three bands really came to life once the alignment was completed. As with every Tropic I have worked on so far, this one is very sensitive and is now an excellent performer.
Now I still need to clean that switch, and replace the antenna and ground leads...
What A Diff'rence An Alignment Makes...
[Image: http://www.philcoradio.com/images/phorum...e00013.jpg]
Philco apparently expected the service man to align the set inside the cabinet. But there is a problem with that - when in the cabinet, it is difficult if not impossible to reach all of the adjustment screws.
So I improvised - I took a photo of the front of the radio, focusing on the dial scale. Then, using Paint Shop Pro, I made a negative image of the scale, printed it, and temporarily taped it to the dial back plate for alignment purposes. This really made performing the alignment much easier.
The alignment was way off. Once the IF transformers were adjusted back to the proper 455 kc frequency, the AM band was then way, way off. A local station (WITZ, 990 kc) was coming in around 650. I could no longer hear my SSTRAN which is set at 660.
But once I went through the entire procedure, I not only managed to get the AM band more or less back on track (pun intended), the problems I initially experienced with very broad tuning at 660 and oscillation from 670 to about 750 kc disappeared. All three bands really came to life once the alignment was completed. As with every Tropic I have worked on so far, this one is very sensitive and is now an excellent performer.
Now I still need to clean that switch, and replace the antenna and ground leads...
--
Ron Ramirez
Ferdinand IN
