Peerless K-241-D Mic Input

[CJ]

Well, lucky me. This Peerless I took apart just had a few leads that had become un hooked from the header. so I will be able to fix it this classic and use it in a project.

Does this mean I am not going to take it apart>
No way!

But, I do not have to ruin it either. My x-former guru friend had already dissected one, so all I wanted to do was un can the thing and get the lam type and a few other details. So here we go again.

The transformer in question:

Brass pem nuts have to be releived to get the header off:

Lead numbering:

http://vacuumbrain.com/The_Lab/Peerless/k_4.jpg

LPeaking under the header:

http://vacuumbrain.com/The_Lab/Peerless/k_5.jpg

There is a cavity under the header:

http://vacuumbrain.com/The_Lab/Peerless/k_7.jpg

The first lid came off very easily. So I figure the x-former got jangled pretty good and must have come loose from it's mounting screws, thus breaking the ywo leads.

There are two more lids to pull off. I used the heat gun to warm up the wax. This is lid number two:

Under lid number two:

http://vacuumbrain.com/The_Lab/Peerless/k_9.jpg

Lid number three comes off. All the lids acame apart pretty easily.

http://vacuumbrain.com/The_Lab/Peerless/k_10.jpg

I tapped the case on the ground to get this pup out of it's cage:

http://vacuumbrain.com/The_Lab/Peerless/k_11.jpg

Taking off the fish paper.

http://vacuumbrain.com/The_Lab/Peerless/k_12.jpg

http://vacuumbrain.com/The_Lab/Peerless/k_14.jpg

http://vacuumbrain.com/The_Lab/Peerless/k_15.jpg

http://vacuumbrain.com/The_Lab/Peerless/k_16.jpg

Primary lead break-out:

http://vacuumbrain.com/The_Lab/Peerless/k_17.jpg

Secondary lead brek-out:

http://vacuumbrain.com/The_Lab/Peerless/k_18.jpg
Nice honest chunk o nickel:

http://vacuumbrain.com/The_Lab/Peerless/k_21.jpg

Lam type. There were 52 of them:

http://vacuumbrain.com/The_Lab/Peerless/k_lams.jpg

Putting it back together:

OK, some test data .

Square wave testing. Not much ringing going on.

1 k Hz:

http://vacuumbrain.com/The_Lab/Peerless/1k_sq.jpg

100 Hz:

http://vacuumbrain.com/The_Lab/Peerless/100hz_sq.jpg

B-H curves. !5 Hz sine wave:

http://vacuumbrain.com/The_Lab/Peerless/15hz_sine.jpg

15 Hz square wave:

http://vacuumbrain.com/The_Lab/Peerless/15hz_sq.jpg

Frequency curves.

Open circuit:

http://vacuumbrain.com/The_Lab/Peerless/freq_1.jpg

32 k ohm- 0.1 uf network on the secondary:

http://vacuumbrain.com/The_Lab/Peerless/freq_2.jpg

OK, structure:

1/2 pri--sec--1/2 pri

Single coil, bi-filar wound, pri is 42 ga wire, sec is 48 gauge wire.

Pri turns: 492
Sec turns: 6022

Two primaries, two secondaries.

DCR:
each pri- 17,8 ohms, tap at 11 ohms.
each sec-1.465 k ohms-no taps

Inductance:

each pri-2680 milliHenries-tap at 481 mH
each sec-340 henries

Leakage:

Capacitance-115 pf from any pri lead to any sec lead.

Inductance: 1.51 mH with sec shorted

Total weight: 13.42 oz. Coil/core: 5.37 oz.

Three mu can construction.

1:12 turns ratio

Catalog page at www.vacuumbrain.com

 

[fazeka]

What's next? S-217-D?!? :razz:

Mighty impressive!

A fine job, as usual. :thumb:

:guinness:

 

[CJ]

I need to clarify the secondary winding on the K-241-D.

The primary is bi-filar, but not the secondary.

The secondaries are split coils wound side by side

Sorry if you already wound one!

A bi-filar winding using 48 ga wire would be pretty tough.

cj

 

[strangeandbouncy]

CJ,

i love these articles! I Love transformers (in my gear), and slowly glean snippets about them here on the forum and elsewhere. There is nothing quite like the thrill of taking something to pieces, and there is no way I'd ever disseminate any of mine, so thanks CJ! I am even more impressed that you get them back together again!

there is something deeply voyeuristic about your posting, Like attending an anatomy seminar, but without the fainting/puking/resolving that medicine really isn't for me, or is that just me?!? :roll:


Thanks for the wonderful insight,

Andy P

 

[CJ]

Thank's Andy!
I have a blast taking them apart, as each one is a little different.

I had to solder some wire to the leads to get the 241-D back together:

I cleaned all the old solder out of the termminal block.

http://vacuumbrain.com/The_Lab/Peerless/header.jpg

Once I got both secondaries wired up, the phase shift went way down.

Next up, Stancor, Western Electric, Kenyon......

I am going to use the Peerless in a DIY Telefunken V-72

 

[gyraf]

Thanks, CJ..!

Damn, I enjoy these hacksaw essays..

Jakob E.

 

[alk509]

You're the man, Chris! :thumb:

Can we do a "hacksaw chronicles" meta?

EDIT: We already have a transformer meta... Nevermind.

Peace,
Al.

 

[Shattersignal]

It's too bad all the pics are gone.  I'd love to see this sort of thing archived!