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

640b e-cap values
#1

Morning guys -

Found this nice looking Philco at an antique shop last month and decided to bring it home as a birthday present to myself.   

https://philcoradio.com/library/download...l.%201.pdf

After rebuilding the bakelite blocks, checking resistors, tubes, etc, this set has hum that does not change with volume.  As I was about to swap out tubes one by one I noticed part #68, a 3 part electrolytic can on top comprising 2mfd, 2mfd and 1mfd e-caps.  I missed this and suspect it could be the hum source.  Been unable to locate these value electrolytics so far.  Are there alternatives for 1mfd and 2 mfd, 450v caps?  AES has these but only at 50v rating.  

Looking for guidance.  
Thanks very much fellas,
Paul


Attached Files Image(s)
   
#2

Good morning Paul,

Yes, that will be the source of the hum issue. Because of their low value and where they are used in the circuit, you could use non-electrolytic caps. But JustRadios and Sals Capacitors both carry 450v electrolytic caps in 1 and 2 uF sizes.
#3

Paul,

I have always been able to rebuild the multy-section electrolytics.
And, as Brad noticed, because of where they used and their values, you do not have to worry about the ripple rating and the temps, so use any reputabe mfr electrolytic caps, and they should all fit nicely inside this cap, and they have the common GND lead, so easy to do.

People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
#4

Finally. Hum is so hard to troubleshoot for me.
Thanks very much Brad and Mike.

Paul




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Philco model 38 code 121 not receiving signal.
So one last question before I finish this radio. Regarding the speaker and output transformer. I salvaged the original o...Stormlord5500 — 09:31 AM
462ron
It’s on the bottom of the homepage of our Philcoradio.com homepage! Ron462ron — 07:20 AM
Model 70 Cabinet Trim
Steve might have some trim left. Not sure he is making anything.morzh — 06:12 AM
Model 70 Cabinet Trim
Hello musar, First all welcome to the forum and yes that is true that steve stopped making trim . Sincerely Richar...radiorich — 12:13 AM
Model 70 Cabinet Trim
I have recently come into possession of a Model 70.  The trim around the base needs to be replaced.  If this were years ...musar — 12:07 AM
philcorepairbench.com - shadow-meter
Anyone know of a way to recover these files from the repair bench? Thanks. fenbach — 11:16 PM
Philco model 38 code 121 not receiving signal.
That's true. Of course If I were to get a vtvm I'd probably have to sink money in to it to get it working right. Probabl...Stormlord5500 — 08:44 PM
Philco model 38 code 121 not receiving signal.
A DMM is good enough. One rarely has to measure indictance, but if you do, short of getting a serious LCR meter (I hav...morzh — 07:35 PM
Testing a speaker and output transformer Trutone A2-G
You guy's are right on. I found a broken wire on the speaker plug that I replaced and all is well now. Have better volu...murf — 03:43 PM
Philco model 38 code 121 not receiving signal.
I need to get a vtvm. I think that little component tester is just more accurate. Plus it shows the inductance which is ...Stormlord5500 — 03:07 PM

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

>