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

Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5

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
5U4 vs 5Z4 tubes
The pinout is the same but the 5U4 has a 3 amp filament, verses 2 amps or less on the 5Z4. I think that the pinout of a ...Arran — 12:04 AM
Philco 42-345 Restoration/Repair
By the way. osanders0311 Take a look here: Dial cord stringing Guides May be here you can fount correct string settin...Vlad95 — 11:15 PM
5U4 vs 5Z4 tubes
5U4 and 5Z4 almost identical. I think nothing happened if you left 5U4 instedad 5Z4 long time. Just heater current 5U4 ...Vlad95 — 11:02 PM
Philco 42-345 Restoration/Repair
Hello Vlad95 , Very Funny ! Sincerely Richardradiorich — 11:01 PM
Philco 42-345 Restoration/Repair
RodB You are European yourself   :evil: I'm Canadian for the last 30 years  :snowman: But not Yankee  :lol: Vlad95 — 10:49 PM
Philco 42-345 Restoration/Repair
The band switch selects different oscillator coils for the band selected. I would look for a bad connection in the switc...RodB — 10:31 PM
Philco 42-345 Restoration/Repair
Hang in there...PaulPaul Philco322 — 09:30 PM
Philco 42-345 Restoration/Repair
The thrill is gone again, thought I was close to being done with it. Well Friday it was receiving broadcast, Saturday mo...osanders0311 — 07:47 PM
Help with Supreme 599
Iam getting closer to fixing it. I bumped Up the tranny voltage to get 5v on the 80 tube. I gan get the needle to move ...daveone23 — 03:41 PM
Philco 42-345 Restoration/Repair
Hello RodB, Checking my previous post I realized you're the one with the 42-340. I replaced the string for the tuning...osanders0311 — 03:12 PM

[-]
Who's Online
There are currently no members online.

>