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

Hum after recapping
#1

I just finished recapping my Farnsworth AC-70. I am getting a very slight hum still when I turn it on, nothing compared to it's original level, and I was wondering if there were other sources that could create it (tube?). There is very little on the internet though what I did find indicated that some radios just did hum even when new. I am also considering I might be too picky?  Any feedback would be great!
#2

I am leaning towards you being "too picky" because I am too picky as well. Some of the old 20s radios hum, noticeably IMO too much, but that is the way they are.  Beyond that , fixing them to not hum is in fact modifying them, something I generally won't do.

Thirties (1930s) radios are generally better, but the better is usually tied to the original price.

If you are sure that you rebuilt it correctly, what you are hearing is likely normal.

The questions people are going to ask are:

Does the hum increase with volume?

Does the volume and tone control(s) seem to work properly? Have they been cleaned - with the right compound?

Have you or anybody added an input - phono, MP3 or other?

On a transformerless model, sometimes (very seldom) hum can be reduced by reversing the power plug (at the wall socket). This is more common with ground loops created by adding the above input devices.

"I just might turn into smoke, but I feel fine"
http://www.russoldradios.com/
#3

Ok, my being picky is good. I actually had to put my ear to the speaker to hear it. The slightest increase in volume and it is undetectable. I just didn't want to cause any harm by letting it go like that. No additional inputs added and, because of very little free time, recapping took two weeks (literally replacing one cap a night) so I was slow and methodical (aka "picky"). Thanks for the reassurance. It's my first radio. Glad I didn't burn the thing up!




Users browsing this thread:
[-]
Recent Posts
Philco model 38 code 121 not receiving signal.
I think this thing is way more accurate than my Walmart DMM. :DStormlord5500 — 08:19 AM
Philco model 38 code 121 not receiving signal.
Thankyou for the kind words sir. I double checked it with my component tester and it read 2.7 ohms at .02mH.Stormlord5500 — 08:14 AM
PT 6 chassis screws size???
Hello bridKarl, that sounds right or maybe 8/32 . Sincerely Richardradiorich — 01:00 AM
PT 6 chassis screws size???
Have this done except for missing chassis screws. It looks like 1 inch 6/32 sheet metal screw may work but can anyone s...bridkarl — 10:32 PM
Philco model 38 code 121 not receiving signal.
Hello Stormlord, Well done on rewinding that coil it turned fairly good for your first one. Sincerely Richardradiorich — 09:12 PM
Philco model 38 code 121 not receiving signal.
Well here it is. It ain't pretty, but hopefully it'll work. I checked it with my DMM on continuity and it keeps and r...Stormlord5500 — 08:56 PM
Philco 42-345 Restoration/Repair
Yes, 57 is an electrolytic cap that should be 12 mfd 400 volts according to the parts list from the Phorum library schem...RodB — 06:01 PM
Philco 42-345 Restoration/Repair
Looks like if I am reading it correctly it looks like the silver capacitor#57 that appears to be a replacement is of a l...osanders0311 — 05:09 PM
Philco model 38 code 121 not receiving signal.
Thanks Arran. Yeah this plastic is pretty thin. It's a little thinner than the original stuff. It kinda reminds me of p...Stormlord5500 — 04:37 PM
Testing a speaker and output transformer Trutone A2-G
The equivalent of one short turn is basically the same as that of a shorted load. If it is the primary's turn, then the ...morzh — 03:53 PM

[-]
Who's Online
There are currently 751 online users. [Complete List]
» 1 Member(s) | 750 Guest(s)
Avatar

>