11-29-2021, 05:30 PM
Absolutely. If the value was critical, they put a variable cap in parallel with the fixed cap.
|
Philco 90 restoration
11-29-2021, 07:07 PM
Yup, as Steve and Bob said. After all, these were consumer products, not scientific instruments. Usually "good enough" was...good enough.
-- Ron Ramirez Ferdinand IN 
12-01-2021, 03:39 PM
I watched a YT video from Mr Carlson last night on restoring an FADA radio. That's where I heard the comment. Doesn't mean he's right though! Maybe it was something unique to that manufacturer.
12-01-2021, 09:23 PM
Could the components even be selected before the radios have been completed and powered up? Anyway, just think about the bottleneck this would create on an assembly line.
Steve M R Radios C M Tubes
12-01-2021, 10:08 PM
The design engineers selected the components when they designed the circuits, prior to the beginning of production. Changes were (often) made during production, and these changes were then incorporated into production and usually (but not always, as we know) documented.
-- Ron Ramirez Ferdinand IN
12-01-2021, 10:47 PM
It just wouldn't be economically feasible to select components on the fly.
Steve M R Radios C M Tubes
12-02-2021, 08:22 AM
Makes sense guys. Wow...these pictures on the Philco radio website are haunting. I live right outside of Philadelphia and know exactly where this area is.
https://philcoradio.com/library/index.ph...9-the-end/
12-04-2021, 04:19 AM
I believe that the old style molded mica caps had a tolerance of + or - 5%, and since the values were usually posted right in the service data, either on the schematic or on an included parts list. Of course they also included trimmers, and padder condensers in series with, or in parallel with a coil to compensate for the variations in manufacturing tolerance between one coil and another, some would take shortcuts though and use fixed micas rather then trimmers. I've never worked on a Philco superhet of this era, but I have worked on RCA/G.E/Westinghouse sets, and it is possible to get the alignments on those almost bang on in terms of dial tracking.
Regards Arran 
12-04-2021, 11:29 AM
Bob, PM'd you regarding your "parts chassis"
Thanks, Simon
12-09-2021, 02:21 AM
I'm calling the chassis done. It would be nice to have a matching pair of tube shields but I'm not going to lose any sleep over it.
Next, I'll give the speaker my full attention. [Image: https://live.staticflickr.com/65535/5173...1586_c.jpg]
« Next Oldest | Next Newest »
Users browsing this thread: 3 Guest(s) |
|
|
![[-]](https://philcoradio.com/phorum/images/bootbb/collapse.png "[-]")
