Welcome Guest! Be sure you know and follow the Phorum Rules before posting. Thank you and Enjoy! (January 12, 2025) x

Thread Closed

Hickok 288x
#16

I pulled all the tubes except the 6x5 and the B+ on both c31 caps is nothing (.5v).
#17

new transformer and B+ but the machine is still dead. C20 and c26 are new and fine. 6c4 is good. I noticed the var audio freq knob and fins are frozen but i dont think it makes a difference, its just for audio. Probes still spark but my good machine does too. Where should i start looking?
#18

Does your B+ still drop to near zero V when set warms up? You need to fix that before going anywhere else. If this is happening with only the rectifier installed, then troubleshoot by disconnecting all loads then adding them one at a time. Sounds like a cap shorts when things heat up. Check C18, a 100pF mica cap for shorts. Check the output and band switches as B+ may go to these switches.

Hope this helps.

"Do Justly, love Mercy and walk humbly with your God"- Micah 6:8
"Let us begin to do good"- St. Francis

Best Regards, 

MrFixr55
#19

The B+ stays steady at 277vdc will all the tubes in.
#20

I put the scope on pin 8 of the 6sn7 and read something but i had to crank the scope WAY down to 10m volts and 10ms time. Read the same on the probe. Volts on tube plates are hit and miss.
6c4 = -.6vdc
6sn7 v2 = 243vdc
6sn7 v3 = 195vdc
6sj7 = 260vdc
6sg7 = 11vdc
Why does the pic of the 6sn7s look different?
Whats next to check?


Attached Files Image(s)
   




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Stromberg Carlson 1500 Squeal
Hello Rob, I agree with you—I have one here at my house that I need to check out. It’s way over-engineered just to make...radiorich — 11:05 AM
My Atwater Kent 84
Well getting around to restoring my AK84. Mike was a big part in me being able to snatch this one a few years ago. I won...462ron — 10:57 AM
Plug Voltages Needed For A 1943 CRV-20130 Power Supply
The engine is a B&S 23 inch cast Iron holds 2 quarts of oil. The Generator is a 4 pole 1800 rpm mine was made in 195...David — 10:51 AM
Philco 45-6365 Universal IFT Instruction Manual
Dale: Modified topic as suggested. It is not for a specific project. I found it in a box of stuff I recently purchased...GRG — 10:34 AM
Plug Voltages Needed For A 1943 CRV-20130 Power Supply
That looks a lot like an aircraft connector of some kind ... That is a MIL-5015 style connector, used in a wide v...DaleHCook — 10:19 AM
Philco P45-6365 Universal Transformer Instruction Manual
I would suggest changing the topic from "P45-6365 Universal Transformer" to "45-6365 Universal IFT."...DaleHCook — 10:08 AM
Stromberg Carlson 1500 Squeal
And life just keeps getting more complicated. By dconant. Dittos'Jimradio — 08:01 AM
Plug Voltages Needed For A 1943 CRV-20130 Power Supply
That looks a lot like an aircraft connector of some kind, even if it's a U.S.N power supply. I have a book somewhere abo...Arran — 02:56 AM
Plug Voltages Needed For A 1943 CRV-20130 Power Supply
hello david, I have a similar generator in my collection that features a cast iron, single-cylinder Briggs & Stratt...radiorich — 01:00 AM
under chassis parts locator diagram for 1938 Zenith 9s262
Has anyone gone to the trouble of creating an under chassis parts locator image?  Yes, I can identify components by foll...bobloney — 08:57 PM

[-]
Who's Online
There are currently 1253 online users. [Complete List]
» 4 Member(s) | 1249 Guest(s)
AvatarAvatarAvatarAvatar

>