Posts: 1,114
Threads: 14
Joined: Feb 2013
City: Irvington, NY
I would not sub a 112A for a 71A. The bias requirements are totally different. The 112A requires only -13.5 V bias while the 71A needs -40V. Subbing 112A's will throw off all the bias voltages since they are mainly determined by the current drain of the 71A output stage.
The 112A is actually a 201A battery set tube with an oxide coated filament. Its not really designed for use as an audio output tube.
Hope this helps.
Messages In This Thread
RE: Philco Model 86 - by Mondial - 12-02-2021, 02:33 PM
Users browsing this thread: 9 Guest(s)
|
|
Recent Posts
|
|
91H Code 126 Restore
|
| Hi Nick,
Usually the dashed lines connected to components means the part is a substitute in the circuit for specific ...RodB — 09:42 AM |
|
462ron
|
| Mike when I got to the guy’s house to pick up the set, he gave me a tour of his home and garage. Wow, his living room co...462ron — 09:10 AM |
|
91H Code 126 Restore
|
| I'm pretty sure that the dotted line I circled in an earlier post signifies that it is applicable to the 226 model which...RealRider — 08:05 AM |
|
Philco 49-1040
|
| Hello bob,
that underside looks like it is all original !
Sincerely Richardradiorich — 02:07 AM |
|
Philco 49-1040
|
| Oh yes, many bumblebees and loktal tubes.
The cutout is for the speaker. Here's a photo from a different set.
Bob Andersen — 12:59 AM |
|
Philco 49-1040
|
| Bob;
Looks like another "Bumble Bee" special, like my Brand Z T.O radios. Is that section they took out of ...Arran — 12:19 AM |
|
Philco 49-1040
|
| Hello Bob,
You are like the home for lost tv's like how people bring pets home !
Sincerely Richardradiorich — 12:00 AM |
|
Philco 49-1040
|
| I thought I had an arrangement to restore this set for a customer but his wife said heck no. Instead, he gave it to me....Bob Andersen — 10:29 PM |
|
Philco 46-480 Electronic Restoration
|
| I kept working on reassembly this week. I wasn’t able to solder for a few days while it was too cold (single digit low t...jrblasde — 09:27 PM |
|
Atwater-Kent 84, restoration.
|
| Well, powering it up would be too good to be true, and I had that feeling.
Before I did, I decided to check the coils...morzh — 06:02 PM |
|
Who's Online
|
There are currently 3738 online users. [Complete List]
» 3 Member(s) | 3735 Guest(s)
|
|
|
|
 
|
![[-]](https://philcoradio.com/phorum/images/bootbb/collapse.png "[-]")
