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Grumble, mumble, broken solder tab on a phenolic wafer tube socket...

thorpej

thorpej

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I'm finally getting around to re-capping my Heathkit AA-151. While replacing the screen bypass caps on the 6AN8As, the solder tab for pin 7 on one of the sockets broke off. *GRR*

I have a cache of Belton micalex sockets I could replace it with, but it of course will be a serious PITA that I'd rather avoid.

So, I took a deep breath and devised a repair... the break was below the wafer surface, and appeared pretty clean... so I snipped off a small bit of solder from my roll, used a precision screwdriver to tuck it down into the slot, tight against the visible tab fragment in the socket, tinned the broken off part of the solder tab, and then pressed the tab down into the slot while continuing to heat it with the soldering iron, in an attempt to fuse the tab back together with a solder joint.

It SEEMS to have worked. The tab feels solid against firm-but-gentle wiggling and I measure 0 ohms resistance between the tab and the pin receptacle.

The new cap is in place, and I'm kind of inclined to leave it be now. I do want to eventually replace the 680K dropping resistor on the screen of each 6AN8A (they've drifted just beyond their rated tolerance), but because of their placement, I don't have to be quite as invasive. I'm hoping that this repair will thus be good for the long haul, but I'm wondering if anyone else has successfully repaired a wafer-type socket like this before? (Yes, if I were stripping this thing all the way down, I'd just replace all of the sockets... but this unit doesn't need such a drastic overhaul, so I didn't plan to do much more than re-cap and replace the PECs.)
 
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Will a piece of wire (cap trimming or whatever) fit down in there to reinforce the connection? Looks like pin 7 is grid supply, which could maybe cause some damage if it went open during operation ...

Truth be told, that amp looks like it'd be easy enough to just bite the bullet and do it right ... comparatively speaking anyway ... I suppose a lot would depend on how tidy the original builder was.
 
Don't ya hate it when that happens??? It'll probably work, but I change the socket when tabs break off...
 
I really don't like wafer sockets. They always seem to break on the last connection you need to make.
 
Yes, I really do hate it when that happens. To @sKiZo's question, no, there isn't really space to insert a bit of reinforcing wire. These tabs are actually offset from the pin receptacle, which probably made it a lot easier for the hobbyist kit builder to work with them. Attached is a photo I took after replacing the coupling caps between the PI and the output stage, before I moved on to the screen bypass caps. It's a little crowded in there, which is why I kind of want to put off replacing the socket for now. I may eventually bite the bullet -- I have a few months yet before this unit has to go into production use :-) I'll see about snapping another photo tonight that shows the repair.
 

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gadget73 said:
I really don't like wafer sockets. They always seem to break on the last connection you need to make.
Click to expand...

Been there done that! As much as I hate wafer sockets,if I'm not going to replace it,I don't even attempt to remove the original connection.I just clip the existing component and connect to the remaining lead.
 
Yah, that is what I plan to do with the resistors ... but the caps were all mounted in a lower layer, which made that difficult.
 
I've noticed that most equipment using wafer-type sockets is,far and away,the most crowded,densely packed,difficult to work on (insert your own choice curses here) that I ever have to deal with. Layers? I think some of the pickle-heads that designed this stuff started their careers designing plywood :mad:
 
I do wonder about Heathkits. I've had my AA-50 out again to check the crazy balance and separation concentric pots. I found a dry joint from a replacement film cap and the preamp board, so that fixes the intermittent problem, but now there's distortion coming from somewhere. And I went through the whole amp carefully a couple of years ago.

I see how crowded it is in there for your repair, but if you have the time, I'd recommend replacing that wafer socket (maybe both of them). And talking of pickle-heads, apart from putting the RCA sockets underneath the chassis, who decided that you needed 22 screws in 3 different sizes, to secure the base plate of the AA-50?!
 
arts said:
I've noticed that most equipment using wafer-type sockets is,far and away,the most crowded,densely packed,difficult to work on (insert your own choice curses here) that I ever have to deal with. Layers? I think some of the pickle-heads that designed this stuff started their careers designing plywood :mad:
Click to expand...

Maybe they were just thinking ahead to the modern PCB era?
 
Dandy said:
I do wonder about Heathkits. I've had my AA-50 out again to check the crazy balance and separation concentric pots. I found a dry joint from a replacement film cap and the preamp board, so that fixes the intermittent problem, but now there's distortion coming from somewhere. And I went through the whole amp carefully a couple of years ago.

I see how crowded it is in there for your repair, but if you have the time, I'd recommend replacing that wafer socket (maybe both of them). And talking of pickle-heads, apart from putting the RCA sockets underneath the chassis, who decided that you needed 22 screws in 3 different sizes, to secure the base plate of the AA-50?!
Click to expand...

There are additional wafer sockets -- 2 more 9-pin (for the 6EU7s) and 2 7-pin (for the 6AU6s). Of course the tubes that get hot (the EL84s and the GZ34) have nicer Bakelite sockets...
 
I don't mess with trying to repair the phenolic wafer sockets. If a pin breaks, I just bite the bullet and replace it with a standard micalex, belton or ceramic o.s. socket. Better off in the long run.
 
gadget73 said:
Ever worked on TV sets or German gear? Yeesh. Talk about layers and crowding.
Click to expand...

Gadget,the only television sets I work on are Philco Predicta's,and most of the antique radios I service are Blaupunkt,Lowe-Opta and Telefunken.
Believe me,I know what you're talking about! Luckily,I have small paws:).Despite my own German ancestry,I curse those engineers regularly:rant:
 
arts said:
Gadget,the only television sets I work on are Philco Predicta's,and most of the antique radios I service are Blaupunkt,Lowe-Opta and Telefunken.
Believe me,I know what you're talking about! Luckily,I have small paws:).Despite my own German ancestry,I curse those engineers regularly:rant:
Click to expand...
Why use just one part when five work almost as well (Auf Deutsch)?
 
You got me beat if you do Predictas. I've done two, one a smallish Admiral portable and the other is a 1953 Philco console model. Two chassis, which made it a lot more workable but boy was that thing packed. It was my second restoration, the first was a 1939 Philco 39-116, the one with the Mystery Control that got all new wire as well as a lot of other parts.
 
Pio1980 said:
Why use just one part when five work almost as well (Auf Deutsch)?
Click to expand...

Quite simple Pio. Because performance and complexity often go together.That and we just can't seem to do anything the easy way...:p

Gadget-The pride and joy of my radio collection is a Philco Model 19 cathedral,chassis type 126. Up until we lost our ''oldies'' station,the set was in daily use.

Meine Freundin kocht Sauerkraut und Würstchen , wie ich dies eingeben . (It's been a long while since I've had to write anything in German,so this may be gibberish!)
 
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