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

Softening a stiff spider?
#1

My 38-7 has a nice big speaker, but not much bass.  It looks like the spider has stiffened over its 80 year life (understandably), and the cone can't follow the larger bass motion.  Is there anyway to soften the spider, and make it more compliant?  If it was an old baseball glove I'd put neatsfoot oil on it.  But I don't have any clue about cardboard.  It otherwise looks to be in great shape, so I'd hate to make it worse.
#2

I just spent a week chasing down cracks and spots where it separated on the cone at the rim where it flexes that appeared as I continuously played as much bass as I could, then patch and gently flex the center cone which I had repaired a couple months back and massaging it back to life. As the glue dried, I gently persuaded it to flex right at the outer edge of the cone. The glue took 24 hours to fully dry. Gave a lot of working time to it. My cone was completely shot with severe holes and cracks, along with disintegrating paper. It would tend to come apart at the areas where I hadn't fixed yet. The thing is to allow the center cone to vibrate at whatever rate it needs to, while having the outer edge secured with a good flex. THIS SPEAKER SOUNDS GREAT!!! The bass is beautiful, full, dynamic and LOUD!!! However, the speaker itself looks hideous!!! It probably would be in your best interest to have it re-coned, but if you're adventurous...  Icon_mrgreen


Attached Files Image(s)
   
#3

Your speaker looks like it has been through a war zone!  It is encouraging to see how much repair they can take and still function.
Until my speaker degrades a lot more, I'll just accept that it is too stiff, so no re-coning in it's immediate future.    If there was a speaker-yoga class down at  the health spa, I'd sign it up.
#4

I'm listening to it right now. it...sounds... FANTASTIC!!! It is incredible how they can bounce back to life...  Icon_eek  That speaker-yoga class might not be a bad idea! (I do something similar myself whenever I embark upon a new project. You must be "ONE" with the radio.  Icon_e_biggrin  It really does wonders for me and the projects always seem to come out favorably!!!)  Icon_thumbup Just for the fun of it, have you checked your alignment lately? That will cause lack of bass, if it is misaligned...
#5

You mean the IF alignment, not the speaker coil, right? I did a quick alignment when I got it running, but I did not play with the trim capacitors. Unfortunately I noticed last night the dial calibration is nonlinear, so I need to go back in there and play with those, and will touch up the IF again as well. Thanks!
#6

WOW,,,,there are always cones on E-Bay,,,,CHEAP
#7

Yes, but not 14 inch cones such as used in 37/38-116 and 37/38-690 speakers.

--
Ron Ramirez
Ferdinand IN




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Zenith H725
Good ideas, thank you Arrange and Rich. I have the adhesive aluminum foil already and can try that immediately. More ...EdHolland — 10:18 AM
Graphics for majestic 1050 dial glass.
Murf; I found this thread on the ARF, the first photo has a pretty good view of the dial glass. Regards ArranArran — 01:12 AM
Zenith H725
hello Ed, how about that speacial tape used for ducting it's like foil or how about thin piece of aluminum roof flash...radiorich — 12:19 AM
Zenith H725
Ed; One material that I have seen, but never tried for this was material for making exhaust gaskets, it's similar to ...Arran — 11:42 PM
Zenith H725
I just remembered, I have some hi temp silicone rubber material which could do the trick. Or a piece of FR4 laminate. Th...EdHolland — 08:39 PM
Zenith H725
The PSU filter cap arrived today (thank you USPS!) so I will work on that later. Meanwhile, I have the dial, speaker...EdHolland — 06:42 PM
Philco 610B oscillator wiring
Thanks Terry. After checking my notes I think I recorded about -10v at the 6A7 G4/control grid. The screen grid (G3 &...Tubester — 05:59 PM
The list of my radio & TV collection!
Magical chords of forgotten melodies, old nostalgic music on an old radio... Saturday night blues on the Mid-Waves on an...RadioSvit — 12:20 PM
Philco 42-345 Restoration/Repair
Thank you MrFixr55 the issue with this radio is that the internal coil antenna is missing and there was a wire in its pl...osanders0311 — 11:34 AM
Philco 610B oscillator wiring
Regarding the oscillator circuit which is comprised of the 6A7's cathode, control grid, and screen grid. These elements ...Radioroslyn — 10:33 AM

[-]
Who's Online
There are currently 2806 online users. [Complete List]
» 1 Member(s) | 2805 Guest(s)
Avatar

>