I would try JB weld if you can. The brittle nature of super glue has gotten me more than once when trying to apply a lever type load on a repaired part.
I got my belts from Adam's as well. You can't beat the shipping time and postage. Much better than trying to glue orings together or searching hardware stores for the correct OD.
Don't use JB weld in a switch, it's often metal filled it could cause problems, tone controls are sometimes in B+ circuits so it definately would there if anywhere. Use regular two part epoxy, preferably the type that takes 24 hours to cure. I don't know what the fixation is with using J.B Weld in everything, it's just a high heat epoxy, but don't use metal filled epoxy in electrical equipment.
Regards
Arran
I know JB is iron-filled. However I honestly do not see what the problem is. The places where the glue goes are far enough from the place they could cause shorts (btw JB is non-conductive despite the ferric filler).
On either side the drop of it touches the contacts, but does not short anything as it is only one contact it touches. And even if it were conductive, it is no different from the rivet or the contact itself, a long as it touches only one, and it does.
Anyway, I glued it yesterday, and gave it a try this morning. Works beautifully! The tone control does what it says and the radio sounds great! So far the best sounding raio out of the few I have.
(This post was last modified: 07-14-2012, 10:41 AM by morzh.)
Quote:I know JB is iron-filled. However I honestly do not see what the problem is. The places where the glue goes are far enough from the place they could cause shorts (btw JB is non-conductive despite the ferric filler).
On either side the drop of it touches the contacts, but does not short anything as it is only one contact it touches. And even if it were conductive, it is no different from the rivet or the contact itself, a long as it touches only one, and it does.
Anyway, I glued it yesterday, and gave it a try this morning. Works beautifully! The tone control does what it says and the radio sounds great! So far the best sounding raio out of the few I have. [quote]
My point is why take a chance, the fact that it has iron in it automatically makes it a no-no when it comes to RF circuits, unless you are trying to glue a ferrite rod back together. J.B Weld seems to have a cult following, thanks to slick marketing campaigns,
much like duct tape, and Krazy Glue, where people use it for absolutely everything even when they shouldn't and where far better alternatives exist. Another pair is Gorilla glue and silicone, Gorilla glue works fine when it's used the right way, when not used the right way it's a nightmare to undo and clean up. Silicone works good around a bathtub, it works good for recementing a loose tube base, but is absolute garbage for repairing speakers.
Regards
Arran
The reason I suggested JB weld was because it just about the strongest 2 part epoxy, bonds to everything, non conductive, won't degrade or get brittle over time, and is available everywhere. Clear 2 part epoxies are pretty D**n weak in any kind of stress application like a switch.
The 5 minute epoxies and superglue are more like the "duct tape" to me....
My expeience with regular clear epoxies tells me they would not hold well a broken thin part that costantly flexes. Never worked well. Hype or not, it is a strong epoxy, and for me it is a good chance to see how it works. Conductivity of it is zero, made sure of that when it cured.
And it is not more expensive than a regular cement or epoxy, 6 bucks a pop.
Anyway, this is not really a worthy subject to be breaking spears about. If it works, it works.
I have a question for you about the candohm. I replaced mine for longevity reasons and piece of mind. The schematic has the candohm grounded on (I think) the 3rd tap. Did you do this? I can't see any wires going to ground in your chassis pics. I'm trying to find some noise issues with my set and I grounded it there.
Please post schematic or link here. something does not sound right to me. Candohm is usually used as a voltage divider and rarely terminates in B- or ground in 3rd tap of a four tap unit if that i's what you have. Not unheard of, but let's have a look. Associated capacitors etc... will tell us what is right. Maybe perfectly OK and third hook is B-, and there might be bias supply, well, hard to do this blind.
OK I see 5 section candohm on schematic, and as suspected creates negative bias supply with respect to ground if properly wired and part is good. Some Zenith power supplies and voltage dividers are quite tricky. Has been my rule that if one section of candohm is bad, cut it out, mount a terminal strip, get appropriate discrete resistors and dress them against chassis to disperse heat, fuse the set, and of course replace electrolytics and all paper caps.
Since there is a voltage chart, a quick check of the audio section should reveal any major flaws. Beware that modern meters do not load down circuits, so higher readings are likely in many cases.
Yes there is the GND tap, I think third from the bottom.
Obviously I followed the schematic and GND-ed it. I used a green wire to connect it to the chassis, I think it is visible on the photo; if not I could post a new one but of course without it it wouldn't work.
I tell you this: first make it work. If you are satisfied (I am with mine. - I cannot think of a reason to filter anything: it sounds awesome the way it is) - leve it at that; if not, then try to improve, but " if it ain't broken" applies here as well.
As for the GND connection, on the page 3 look at the bottom vie. of the chassis, see the arched green wire in between the two teminal strips, and from one of the terminals it goes to you will see the shiny band going to chassis, I imply stripped the wire and press it between the strip and the chassis which is unpainted brass or copper. Makes for a good Gnd connection.
