stusnyder
02-14-2011, 07:45 PM
picked this up locally awhile back, speaker ripped to bits. I reconed the speaker. Then tried the set and the big BC resistor got hot. I figured the speaker trans was bad, so found one at playthings of the past. Installed that, and no change. So did some checking and found the speaker leads missing insulation and touching under the plug. Fixed that and now got audio and no hot resistor. I still have to recap this set.
If I can recone a speaker, anyone can.:yes:
bandersen
02-15-2011, 01:01 AM
Any tips on reconing ? I have a Philco 60 and 70 speaker to recone.
I swear I stumbled across a good article on reconing paper speakers. It showed patterns for cutting and so on. Now I can't find it anywhere :(
Reece
02-15-2011, 07:43 AM
May not be what you are referring to, Bob, but here are a couple of threads showing reconing.
http://www.antiqueradios.com/forums/viewtopic.php?t=121523&view=previous&sid=a7fd62f594d9aa9fc03e19facc1743b6
http://www.antiqueradios.com/forums/viewtopic.php?t=81223&view=next&sid=f5b17d5d2c2d4cbdc5a01afa0dae0e75
And here are some sources for cones.
http://www.electronix.com/speakershome-audio-grillsmiscellaneous-c-362_369.html
https://taweber.powweb.com/parts.htm
http://www.matelectronics.com/cgi-bin/ss000005.pl?RANDOM=NETQUOTEVAR%3ARANDOM&PAGE=SEARCH&SS=cone&TB=A&GB=A&ACTION=Search
If anyone has any other sources for reconing parts, please advise. It is getting harder to find them, especially in the 4-6" sizes. A lot of the cones you see for sale have rubber surrounds as seen in modern speakers mostly used in sealed baffles. Open back radios work better with stiffer cones afforded by the corrugation of the same cone material around the outer edge. Weber offers some of these. Where you still have a good voice coil, often a commerical cone can be trimmed at the apex to fit and be glued to the old VC/spider assembly.
bandersen
02-15-2011, 01:56 PM
Nope, but those are a good read. The one I saw had actual cutting patterns and formulas to get a perfect cone from a flat sheet. It also showed using toothpicks to center the voice coil.
GuyIncognito
02-15-2011, 03:34 PM
How about this article (with cone equations)?:
http://www.nostalgiaair.org/References/Articles/TheFlash/Flash03.htm
My Atwater Kent Model 45 came with a Model E speaker, the cone of which was attacked by a squirrel! I was able to create a working (perhaps even good looking) cone using black artist's heavy rag paper stock from the local Michael's craft supply store. It isn't quite as cool as that impossibly thin plywood/veneer that they originally used--but it's neat, it works, and it bears up very well to casual scrutiny.
For a horrifying moment, I considered attempting to replicate the original cone's wood grain with "appropriately" patterned vinyl shelf paper....think 1970's station wagon**SHUDDER**.
stusnyder
02-15-2011, 04:51 PM
Bob I'll post some pics of mine...not the most perfect looking thing but sounds ok.
Reece
02-15-2011, 05:45 PM
When making one's own cone, there remains the problem of the outer surround. It almost has to be made from cloth or chamois. Some early thirties speakers were made that way. Also getting the suspension compliance right has to be taken into account. Too floppy and the cone will bottom out and distort. Too stiff and bass suffers. The front spiders mounted with a screw on early speakers could be made as stiff as required, depending on the material thickness and how the spirals are cut.
GuyIncog: 1970's station wagon ::)
stusnyder
02-15-2011, 08:52 PM
bob, I measured the speaker depth and the dia. The cone I got did not have the bottom cut out, I had to make the cut out. What was left was the voice coil and the fabric around the outside edge. I cleaned off all the glue and paper on the fabric. The new cone has a rubber material around the outside edge. I cleaned off the glue and paper on the voicecoil. I left the voicecoil in place, put glue on it, sat the cone in place, glued the fabric to the rubber, and put the retainer carbord ring on and screwed it down and left alone for a day or 2.
bandersen
02-15-2011, 10:00 PM
Thanks for the tips. I hadn't considered the outer surround. I think I'd better try to use a pre-made cone with surround rather than roll my own. Seems the missing voice coils will be the really tricky part :scratch2:
stusnyder
02-15-2011, 10:07 PM
if your voice coil is missing, you almost have to use a micrometer to get the dia. you need.