Can a 554C Subset Be Rigged to Work With a D1?

[rp2813]

Attached is a photo of the 554C after following instructions provided by poplar1 in this thread.

The second R in RR is obscured by a yellow wire attached to YL2 and the C is obscured by the black ringer wire connected to RR.

Does this scheme look correct for a working ringer?  I know either the red or black ringer lead needs to come off to disable the ringer.

I understand that the band-aid fix for sidetone with a 554C may not help much if at all, but I'd like to try it, as I'm at the very edge of my exchange and my 500T isn't too bad.  Is it just me (very likely) or have specific instructions on how to wire for this band-aid gotten buried in this discussion or not yet been provided?  None of the links seem to address it. 

I'll admit it -- I need the "For Dummies" explanation on all of this.   Words and colors are just my speed.

Shots of the switch & dial wiring will be forthcoming.

[unbeldi]

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[unbeldi]

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[rp2813]

Excellent!  Thanks for the confirmation.

The only vermillion date on the box is I 31, and it's on the inside top of the cover just above the holes at the gong end.  There's nothing on the wood blocks. 

I didn't realize the inverted gongs were something special.  I'll have to compare with my 634BC.

The only thing I found wrong with the wiring scheme when I followed the instructions provided here was that the yellow lead from the ringer capacitor was terminated on B, so I moved it to YL2.   I don't know why it was like that or whether its position there would have had any effect on sidetone, but will give this box a try now that it's configured properly.

I also just noticed that the black lead terminated on C appears to have detached from its spade and is being held in place by its bare wire end, so I'll solder it back onto its spade.

The last time this box was in regular use, it was in GTE/Verizon territory (not that that should make any difference) and relatively close to the CO.  Sidetone may not be as bad where I'm located now, but I will definitely try switching the red and yellow leads.

Later today I hope to post a picture of the switch and dial wiring to make sure it's correct.

Thanks for all of the expert help thus far.

[unbeldi]

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[unbeldi]

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[rp2813]

Both condensers are inside the one box.  The highlighted edge is a section that has been folded around the edge to make a seal.  It's like that on all sides except the top, a variant of the way a stick of butter is wrapped.

This part of the phone dates back to 1931 as well, although 4th quarter.  That's another reason why I'd like to have it teamed up with a 1931 subset.

As you can see, there are jumper leads installed but I can't recall exactly when or why.  If they're still necessary, I'll try to find better material, and I'll attach spades to them.

Connected to the 634BC, the only loud click happens as soon as the handset goes off hook, which is great.

I'm interested in reading comments about this wiring scheme.

[unbeldi]

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[rp2813]

WOW!  And YES! 

The #4 dial came off of a thermoplastic 302 that it had been on since at least the 1950s and probably longer.  It functioned as a bootleg upstairs extension into the 1970s and my sister and I used to beat on that dial trying to be the 17th or whatever caller into radio station switchboards.  Many years ago I found a celluloid number plate for it.

Should gaskets not be used on D1 sets, or should it be a caramel colored one?

I'll check ebay for the proper jumpers.

Right now I'm going to solder the one spade on the 554C and then hope to give things a try with it.  I'll report in afterward.

[unbeldi]

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[rp2813]

I'll take a look at the dial.  It should seat better without the gasket.

Re: the sidetone switch, only the yellow talk condenser lead is long enough to reach L1.  Does it matter which yellow one I move?

And P.S. from further up -- the ringer coil is from I 31.

[unbeldi]

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[rp2813]

Remarkably, I tried it with the yellow condenser lead switched with the red mounting cord lead and it worked fine, with sidetone stronger than the 634BC but tolerable, about the same as with my 500T.

After seeing the most recent post, I went back and looked at the diagram.  I don't know why I thought the condenser lead was involved.  I put the condenser lead back on L2Y and switched out the red and yellow mounting cord leads.  After that, the phone was dead.  Not even faint static.

I moved the red and yellow mounting cord leads back to their normal terminals and tried the phone again.  It worked, and sidetone wasn't any different than when I had the condenser lead on R.

Could I possibly have the L1 and L2 mixed up on the line cord?  I'm going to try switching the green and red line cord leads, and then switching the red and yellow mounting cord leads.

If that doesn't change anything for the better, unless there's another sidetone reduction strategy to try I'm going to call it good.  I don't use the phone that often, and I had a test conversation on it and if anything, I think the distant party was clearer than with the 634BC.  I don't know if that's because the 557 receiver likes the 554C circuitry better or what.

One thing I'm noticing is that there's a (60-cycle?) humming sound (I've heard louder ones than this, though) and it disappears if I move the subset away from the RJ11C.  There is a DSL filter plugged into the jack, then the line cord into the filter.  This hum was not present with the 634BC just inches from the jack.  I've moved the subset to where the hum is faintest.  Is there anything else I should try?

[unbeldi]

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[rp2813]

Both things fixed!

Switching line cord connections at L1 and L2, and switching mounting cord connections at L2Y and R did reduce sidetone noticeably.  I don't know if polarity does play a role with my subset or what, but instead of completely dead with mounting cord leads switched, it's working and doing it better -- with line connections flipped at L1 and L2.

The humming sound was being caused by the room's ceiling fan. 

At this point, everything sounds as good or better than it did with the 634BC.  Is this an anomaly?  I'm happy regardless.

Next up is connecting the 634BC in my workshop and using it with a 201A "space saver." 

Thanks to all for the expert guidance and most importantly, your patience!  I'm thrilled to be able to use the 554C with my D1!