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

Tis the season...
#1

After getting my 650 to a point called finished i've been playing it in my garage for a while before moving it into the living room. This morning I noticed a loud hum but only when tuned on a station. It had a raspy quality of a renegade light dimmer. It turned out to be a string of outdoor christmas lights, not a big supprise right. Well here is the supprise part. The string was OFF. Suspecting leakage of a hot string to ground from a miswired switch (on a neutral side) I checked the voltage at the end of the heavy duty extension, with the switch off, 0 volts at the end across all three wires!
When I unplug the "dead" string from the "dead" cord the raspy hum goes away. I dont know about y'all but this is a first for this guy.

Buy the way I have restored many a dark string of lights with a telecom sniffer placed next to the dark section. It hums but bad bulbs tend to be very microphonic and you will likly find more than on a section.

By the way this was the first time restoring a cabinet and using lacquer as a finish. WOW I'm sold, the finish came out beautiful while still retaining the character if the piece. This was a train wreck when I started and the final disposition of the radio make me feel good about its journey to today. I'll post pictures soon via links.

Merry Christmas from South Florida

Dave Casazza
Keep em glowin and goin...
#2

The raspy hum caused by a turned-off set of Christmas lights does seem a bit odd.

Where I live, the local talk station often has hum in it. It is the station's fault...when the hum is there, it is there no matter what radio one uses to listen to it, be it at home or in the car.

As to the lacquer finish...much better than stain and poly, yes?

--
Ron Ramirez
Ferdinand IN
#3

That is strange. As Ron noted, some stations seem to have this on their audio. What's even stranger for me, is one radio may have, yet another doesn't show it. But as soon as the program changes, the hum is gone. 800 CKLW is noted for this in my area.

-Brian
If you collect or are interested in antique telephones, please visit Classic Rotary Phones
http://www.classicrotaryphones.com/forum/index.php




Users browsing this thread:
[-]
Recent Posts
My Philco 37-116 Restore
Hello MrFixr55, Thank you for taking the time to explain. I measured 50 volts where you say. Today the 370 volts at ...dconant — 12:51 PM
462ron
Oh that sucks. It’s something easily overlooked. Hopefully it’s nothing more than a resistor! Ron462ron — 08:08 AM
Philco 46-480 Electronic Restoration
Just confirmed that you are correct. It’s the function generator. I connected the signal output probe to one of the inpu...jrblasde — 07:52 AM
Philco 46-480 Electronic Restoration
Ouch, you may be right. Yes, it is solid state. It’s the signal output of my oscilloscope. May be time to crack that ...jrblasde — 07:27 AM
462ron
If you didn’t put a DC blocking cap between the signal generator probe and the plate of the 1st IF it’s possible you ble...462ron — 07:07 AM
My Philco 37-116 Restore
Hi DConnant, The reason why C127 is isolated from ground is because sets of this vintage did not have the center tap...MrFixr55 — 01:07 AM
Philco 46-480 Electronic Restoration
The shield is on the 6H6. It was, in fact, a missing jumper to connect the main chassis ground to the RF chassis grou...jrblasde — 10:58 PM
Zenith H725
When dealing with noise on power lines, time to get my Jackery 240 out. Talk about clean can hold a portable am radio ne...David — 08:52 PM
Zenith H725
Arran - I bet you're right probably vinyl, there was no rubber smell when desoldering it, which you often get with the o...EdHolland — 08:23 PM
Zenith H725
Ed; It was very likely vinyl covered wire given the vintage of the set, there was some rubber/gutta percha wire used ...Arran — 06:34 PM

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

>