01-01-2019, 03:17 PM
Set realigned. Tracking is still off at 15 mc (it comes in at 15.4 on the dial and still can't get it any lower) but I'm going to live with it.
Before the realignment, though, I remembered that I had a junk 53-960 chassis out in the garage. Its tone control is 5 megohms. From my previous experience with early 1940s Philcos, I remembered that they used a high value tone control (5 to 6 megohms) in a circuit which connects between the tone compensating tap of the volume control and the plate of the 1st audio tube (not the audio output).
With that in mind, I removed the 5 megohm tone control from the junk 53-960 chassis, cleaned the control, cut off its control shaft and tried to flatten it as best as I could. Then I installed it in the RCA, modifying its tone control as follows:
[Image: http://philcoradio.com/images/phorum/6T2/6T2_064.jpg]
The original C28, .035 uF, was removed and replaced with a .01 uF cap, connected to the plate of the 6F5 (instead of the plate of the 6F6) as shown above.
The radio now has a very mellow, pleasing sound and the tone control is very smooth and effective from treble to bass.
I'm about to reinstall it in its freshly refinished cabinet and call it quits on this set.
Well, it still needs a new dial cover (the original is badly yellowed) but otherwise, this one is finished.
Before the realignment, though, I remembered that I had a junk 53-960 chassis out in the garage. Its tone control is 5 megohms. From my previous experience with early 1940s Philcos, I remembered that they used a high value tone control (5 to 6 megohms) in a circuit which connects between the tone compensating tap of the volume control and the plate of the 1st audio tube (not the audio output).
With that in mind, I removed the 5 megohm tone control from the junk 53-960 chassis, cleaned the control, cut off its control shaft and tried to flatten it as best as I could. Then I installed it in the RCA, modifying its tone control as follows:
[Image: http://philcoradio.com/images/phorum/6T2/6T2_064.jpg]
The original C28, .035 uF, was removed and replaced with a .01 uF cap, connected to the plate of the 6F5 (instead of the plate of the 6F6) as shown above.
The radio now has a very mellow, pleasing sound and the tone control is very smooth and effective from treble to bass.
I'm about to reinstall it in its freshly refinished cabinet and call it quits on this set.
Well, it still needs a new dial cover (the original is badly yellowed) but otherwise, this one is finished.
--
Ron Ramirez
Ferdinand IN
