News: Trouble logging in? Log in from the login page.
May 25, 2019, 04:11:18 am

Author Topic: After GLOW ISSUE  (Read 830 times)

0 Members and 1 Guest are viewing this topic.

Offline pboser

  • Full Member
  • ***
  • Posts: 53
Re: After GLOW ISSUE
« Reply #15 on: November 03, 2017, 09:22:26 am »
OK, thanks.  Those are good suggestions I will implement.

Keep the snow for a while - don't send it east just yet.
Peter Boser

Offline Paul Joppa

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 4830
Re: After GLOW ISSUE
« Reply #16 on: November 03, 2017, 09:42:23 am »
Both of the manuals I have use the same circuit diagram, which shows an obsolete current source design and 2500 ohm cathode resistor. In the manual marked "Second version with corrections" the parts list and instructions show a 3K resistor, but the circuit was not updated. It also shows a 100K resistor across the input jack, but the text and the parts list show 249K. There may be other inaccuracies - these are just the errors I noticed yesterday and today. As far as I know, there was never a more up-to-date accurate schematic.
Paul Joppa

Offline pboser

  • Full Member
  • ***
  • Posts: 53
Re: After GLOW ISSUE
« Reply #17 on: November 03, 2017, 10:05:31 am »
Thank you Paul.  I will change the cathode resistor and the PS caps, replace the diodes and be satisfied.  Oh, how about the grid stopper- what value should that be?

Thanks,
Pete

P.S. As I drive through Maryland toward CAF tomorrow I will pass signs for Joppa, MD.  https://en.wikipedia.org/wiki/Joppa,_Maryland
Peter Boser

Offline Paul Joppa

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 4830
Re: After GLOW ISSUE
« Reply #18 on: November 03, 2017, 11:19:11 am »
Grid stopper can be anywhere from 100 to 10,000 ohms; we've used 220 ohms pretty much everywhere. Carbon composition is widely regarded as the best, but metal or carbon film are acceptable at lower resistances (under 1000 ohms?)
Paul Joppa

Offline pboser

  • Full Member
  • ***
  • Posts: 53
Re: After GLOW ISSUE
« Reply #19 on: November 03, 2017, 11:37:30 am »
Thank you Paul! 

And thanks to Chastity for bringing up the old amps.
Peter Boser

Offline deepgroovebiz

  • Jr. Member
  • **
  • Posts: 14
Re: After GLOW ISSUE
« Reply #20 on: November 04, 2017, 03:48:01 pm »
No problem
If we could only turn the clock back to the 90's, great music, simpler times, visiting Mike in philly and lusting after all the goodies he had laid out on his kitchen table.