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

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

Hallicrafters S-40A
#7

Tex, have you any inderstanding at all what these old Sprague capacitors are? They are leaky...have resistance across them. It has been a mystery among learned radio technicians what inhabits the heads of those guitar amplifier fans. They are removed from equipment because they are the cause of malfunctioning.

I understand that musicians have no savvy whatsoever of electronics, but being a graduate electrical engineer, and having designed electronic equipment for 65 years or so, and/or serviced it as well, It is beyond my comprehansion, how old, leaky capacitors can give just decent performance of audio amplifiers, much less admirable quality of output. In my aged eyes, this is unabashed insanity.

Are you in a position to explain how any degraded capacitors, regardless of capacitance ratings, can make an audio amplifier work properly? I'd want more of an explanation than: "I dunno, but they do".

I don't choose to come across as a lone protector of society. When I replace those old Sprague "Black Beauties, be they color coded or marked with ratings. I relegate them to the trash can. Indeed, I can sell them to some eager buyer, but I view this as tantamount to slipping a drink to an alcoholic. The deed doesn't hurt me, but the results do.

Clue me, please.


Messages In This Thread
Hallicrafters S-40A - by Texasrocker - 02-22-2009, 12:56 AM
Re: Hallicrafters S-40A - by exray - 02-22-2009, 09:49 AM
Re: Hallicrafters S-40A - by Texasrocker - 02-22-2009, 10:57 PM
Re: Hallicrafters S-40A - by exray - 02-22-2009, 11:17 PM
Re: Hallicrafters S-40A - by Arran - 02-22-2009, 11:37 PM
Re: Hallicrafters S-40A - by Texasrocker - 02-23-2009, 04:09 AM
Re: Hallicrafters S-40A - by Doug Houston - 02-23-2009, 07:44 PM
Re: Hallicrafters S-40A - by Texasrocker - 02-25-2009, 01:06 AM
Re: Hallicrafters S-40A - by exray - 02-25-2009, 03:54 AM
Re: Hallicrafters S-40A - by Texasrocker - 02-25-2009, 05:29 AM
Re: Hallicrafters S-40A - by AI2V - 02-27-2009, 05:00 PM
Re: Hallicrafters S-40A - by codefox1 - 02-28-2009, 03:24 PM
Re: Hallicrafters S-40A - by exray - 02-28-2009, 04:06 PM
Re: Hallicrafters S-40A - by Texasrocker - 03-02-2009, 01:28 AM
Re: Hallicrafters S-40A - by codefox1 - 03-02-2009, 03:25 PM
Re: Hallicrafters S-40A - by Guest - 08-06-2010, 05:34 PM



Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Refinishing Ideas
Hi Poulsbobl, I think that you could get away with it.  In the Philco Library, there is a parts listand specs for sp...MrFixr55 — 11:54 PM
Philco 46-480 Electronic Restoration
The sleeving for the transformer arrived early, so I went ahead and finished reassembling. The chassis looks far better ...jrblasde — 10:15 PM
Philco 610B oscillator wiring
I don't know what you are referring to when you say "tube cathode ground". Ground is a connection to the chass...RodB — 05:56 PM
Zenith H725
Good points, Arran. I haven't encountered this problem with any other radio (all earlier vintages), so am learning here....EdHolland — 05:32 PM
Zenith H725
Ed; One thing that I will say about these is that Brand Z was considerate enough to make these mica caps easily acces...Arran — 02:34 PM
Philco 610B oscillator wiring
Do you know what run # your chassis is? It took me a while to find what you were basing updates/modification on as I did...Radioroslyn — 07:34 AM
Need to purchase some accessories for restoration of my Old Philco Radio
COLLEAGUES, Thank you all for such good and important suggestions as how to find good replacement parts. I will go fo...palonso — 07:05 AM
Zenith H725
Here's what the inside of AM IFT2 looked like, and the other pic shows the discs I made to take place of the mica and ke...EdHolland — 07:40 PM
Zenith H725
IF2 will need replacement caps. The arcing was severe enough that the mica is pitted and holed where the HT flashed over...EdHolland — 04:04 PM
My Philco 37-116 Restore
Measuring from center tap like the tube voltages show. Cap 127 is isolated from ground. Cap 127 shown in upper left of p...dconant — 08:05 AM

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

>