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
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
Philco model 38 code 121 not receiving signal.
I use a pair of Mastercraft brand DMMs from Canadian Tire, from what I read most of those DMMs use the same main chip re...Arran — 02:36 PM
Philco model 38 code 121 not receiving signal.
Thank you sir. Yes I feel good and also relieved because this one's been weighing on me a bit.Stormlord5500 — 11:18 AM
Philco model 38 code 121 not receiving signal.
It feels good don't it? Good luck on the rest.Paul Philco322 — 11:06 AM

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

>