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: 28 Guest(s)
|
Recent Posts
|
1930s Stewart-Warner Tombstone Radio need help identifying model number
|
UPDATE: I was able to pick up a signal generator on the cheap (amazingly enough) on feebay and I did an IF alignment fol...captainclock1988 — 09:53 AM |
Philco 91 Schematic
|
Hi Rod,
The resistor connects to pin 4 and the ungrounded side of block 9. From pin 9 of the RF tube to one side of ...dconant — 09:34 AM |
Just got a 49-1613 need to know...everything!
|
I just found your post. I have this exact same model, and have had it since 1985 when I was 15 years old! I performed a ...MuzzcoVW — 09:11 AM |
B&K 1077B no video
|
Hello Tim,
I would if it's a leaky Capacitor So are all 3 of those B- voltages low then ?
Sincerely Richardradiorich — 01:55 AM |
B&K 1077B no video
|
I found a schematic and think I have the problem traced down to the minus power supply. I have very low voltages that go...TV MAN — 12:41 AM |
RCA 15X
|
I'd try replacing the bulb first and if that doesn't do it, then change the 35Z5 and see if the problem goes away.NostalgiaRadioTime — 12:28 AM |
B&K 1077B no video
|
Hello Tim,
I have that exact unit in my shop too plus a Sencore unit there are times I like one or other !!.
Sincerely...radiorich — 11:07 PM |
RCA 15X
|
Everthing goes at once, maybe it's the cold weather, I have had 2 dial strings break and no my little RCA is having dial...Paul Philco322 — 10:26 PM |
Philco 91 Schematic
|
Hi Dan,
I can't explain this specific resistor but I have seen the use of a switch to apply B+ voltage to screen gri...RodB — 09:36 PM |
6TPZ and 5TPO Radio Help
|
I suspect it's been repaired before.
And I suspect whoever repaired it, wanted to re-use old transistors' pin stubs in o...morzh — 09:24 PM |
Who's Online
|
There are currently 7223 online users. [Complete List] » 4 Member(s) | 7219 Guest(s)
|
|
|
![>](https://philcoradio.com/phorum/images/bootbb/asb/right_arrow.png)
|