Posts: 1,114
Threads: 14
Joined: Feb 2013
City: Irvington, NY
Current draw with 18.8 V across the WW resistor is a bit high. Check to see if there is low bias voltage on the control grid of the 42 output. If the coupling cap is leaking or the 42 has excessive gas, it will cause reduced negative bias and high plate and screen current.
You should have approximately the same bias voltage from grid to cathode on the 42 as you have across the wirewound.
I just noticed you have 300V out of the field coil. This is also high. Should be about 260-270 V on the screen grid of the 42.
What is your AC line voltage? Did you increase the value of the first filter cap after the rectifier?
(This post was last modified: 02-07-2014, 01:55 PM by Mondial.)
Messages In This Thread
RE: Model 89 Cathedral - by Mondial - 02-07-2014, 01:44 PM
Users browsing this thread: 1 Guest(s)
|
|
Recent Posts
|
|
HiFi (Chifi) tube amp build - but my own design.
|
| It's the other forum. I'm also in DIY, but mostly read there. Honestly, I kinda jumped into this without much thought to...TV MAN — 10:43 AM |
|
Philco 71 Code 125
|
| Hello,
I am in need of a schematic for this radio. Mine has the three separate circular tube shields and a shadow me...dconant — 08:06 AM |
|
Stromberg Carlson 1500 Squeal
|
| And life just keeps getting more complicated.dconant — 07:57 AM |
|
54C Complete Teardown/Rebuild
|
| Hello Roy,
here is this one
sincerely Richardradiorich — 12:45 AM |
|
54C Complete Teardown/Rebuild
|
| Richard,
Had grabbed it already but thank you just the same. I find myself wanting to find some way to block out the...glyphmon — 12:03 AM |
|
54C Complete Teardown/Rebuild
|
| Hello roy,
here is a link to the schematic .
Sincerely Richardradiorich — 11:54 PM |
|
54C Complete Teardown/Rebuild
|
| Richard,
The Silvertone 2014 also is a transformerless set, so I am incorporating a 1:1 600 ohm audio isolation transfo...glyphmon — 11:37 PM |
|
Preliminary work on wife's Silvertone 2014
|
| Did an alignment today which was interesting. IF alignment went great, almost all was already spot-on. Adjusting on th...glyphmon — 11:35 PM |
|
54C Complete Teardown/Rebuild
|
| The main problem with adding a Bluetooth input is that this set lacks a traditional power transformer to isolate it from...radiorich — 11:19 PM |
|
54C Cabinet Refinish
|
|
I started stripping this cabinet before it got super chilly out because I knew I wasn't going to be able to work on ...glyphmon — 11:18 PM |
|
Who's Online
|
| There are currently no members online. |
|

|