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

Model 70 Speaker Open Field Coil Questions
#5

Cone is easy to remove. Unsolder wires (2) from voice coil to output transformer. The wires maybe held in place by a small coil/spring. Carefully lift the wire up to release them from this coil with a pair of needle nose pliers. Unscrew the screw in the center and then the screws around the circumference of the speaker's frame. You maybe able the lift the cardboard spacer without it sticking or tearing the cone. If not what you do is take an Xacto or small snap blade knife between the cone and the frame. The object is separate cone from the frame and keeping the cone intact. Once the cone is loose from the frame lift it straight out.

If the spider and voice coil are in good condition I've reused them with a new cone. Generally the old cones are pretty beat after 90yrs. Paper is dry a brittle. You can use some diluted fabric glue around the flex area along the outside edge. This will bolster it up for a while.  

< Do you know if there are any write-ups or YouTube videos on this part of the process? 
There was a fellow here on the Phorum that had one of those style spkrs. He rewound the FC and OPT. The posts are for the Phorum but I'm not sure how to find them. I think it was a couple of yrs ago.  Don't know of any videos.

< I assume that the cone can easily be re-installed after the new coil is wound? 
The cone/vc just screws back in. There is some gluing if you end up replacing the cone. You just have to remember to make sure to aim the vc wires towards the opt.

< not sure what gauge wire should be used, but I used #36AWG on the previous one 
Well I'm not sure either. But this we know the fc current rating is 40ma. So you can use that as a minimum rating to determine gauge. Or use a micrometer to check the size of the wire of the open coil. Then you can figure the ohms per foot. Larger the gauge the longer the wire the bigger the coil.

https://philcoradio.com/phorum/showthread.php?tid=22316

When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!

Terry


Messages In This Thread
RE: Model 70 Speaker Open Field Coil Questions - by Radioroslyn - 08-14-2023, 12:27 AM



Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Model 80 Antenna Issue?
Thanks Gary and Rod.  I also found an article in the Philco Repair Bench under Service Hints and Tips, about installi...Hamilton — 12:32 PM
Model 80 Antenna Issue?
Hello Hamilton, here is a little information found in our Philco Radio Library at the bottom of the Home page. Hope it ...GarySP — 11:28 AM
Model 80 Antenna Issue?
I did as you suggested and touching the middle of the volume control did nothing so the coil has to be rewound. Any idea...Hamilton — 10:19 AM
1949 Motorola 5A9M
This would be the second portable in the "other radios" forum where I have a similar one in my collection. I h...Arran — 12:41 AM
Looking for any info: 1977 Ford-Philco Console Hi-Fi Turntable and Radio
Hi PittsburgTost. The record changer looks like a Garrard or BSR (Likely Garrard). The spindles just pull out and pu...MrFixr55 — 11:57 PM
Looking for any info: 1977 Ford-Philco Console Hi-Fi Turntable and Radio
Hello PittsburghToast , Welcome aboard and it looks like gary may have something for you ! now if I dig through my se...radiorich — 11:35 PM
Model 80 Antenna Issue?
You are kind of on the right path. You can touch the grid cap of the Detector/Oscillator 36 tube. I'm expecting a respon...RodB — 08:48 PM
Looking for any info: 1977 Ford-Philco Console Hi-Fi Turntable and Radio
Welcome to the Phorum, PittsburghToast!  I found an old thread that my interest you regarding the quality and worth of P...GarySP — 08:48 PM
Looking for any info: 1977 Ford-Philco Console Hi-Fi Turntable and Radio
Welcome to the Phorum! :wave: We do not have anything on that unit in our digital library. There is a Sam's Photof...klondike98 — 08:47 PM
Model 80 Antenna Issue?
I’ve replaced all the caps and resistors and the radio is working but minimal volume unless I put my hand near the re...Hamilton — 08:24 PM

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

>