Recapping Wire Recorder...easy to do? hard? Help!

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Steve E.
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Recapping Wire Recorder...easy to do? hard? Help!

Post: # 3811Unread post Steve E.
Sat Nov 15, 2008 6:34 pm

How hard is it to recap an old Webster Chicago Wire recorder? I know it can be done, because I have had it done once before on another deck. Can an electronics primitive (that's me) do it if he can solder? Or am I setting myself up for failure and death?

Backstory: A friend just sold me (for a song) a 1940's Webster Chicago Wire Recorder, a model 288-1. It appears to be a deluxe or later version of their 180-1, of which I have a recapped, working model. Came with a cute little mic, which may not be working, and a full schematic. Looks gorgeous.

I am playing as part of a friend's concert @ NYC's Roulette on December 13 and I would love to do a "looping" experiment using the two decks, one for recording and one for playback....you know, the slow echo idea. Mechanically, it's a solid idea--I tried it, and I can drag the wire over both heads, a few feet apart.

The motor seems to work fine on this.

I would consider having Gib Epling do it but I don't want to send this heavy thing--I may get him to go over the mic, which is probably a dead crystal jobbie.

Alternately, anyone in the Brooklyn area who could make quick work out of the recapping, for cash? Let me know.

thanks much,

Steve

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Post: # 3812Unread post Steve E.
Sun Nov 16, 2008 11:51 am

Maybe my question should be....How hard is it, in general, to replace the capacitors on 1940's audio equipment? Does it require training or is it something one can kind of figure out?

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Post: # 3813Unread post cuttercollector
Sun Nov 16, 2008 12:52 pm

I guess the issues are more along the lines of have you ever delt with any piece of electronics from that era?
It is point to point wiring rather than a pc board. The parts can look strainge, especially the capacitors which can have a color code like resistors for their value eiter in stripes around the body or little colored dots on a flat rectangular body (so called "domino" caps) The numbers follow the resistor color code but you have to know the sequence and what it means. Not all the caps may be bad. You could bring it up slowly on a variac and just see how well it works. To find out you either need to know how to measure DC leakage voltages with it running, look for signs of hum or overheating, output tubes with plates glowing getting way too hot etc. Capacitor checkers were made to check the higher voltage coupling caps and electrolytic filter caps. Heathkit, Eico even Sprague and others made them. Sometimes to get these to give an accurate reading one must disconnnet one end of the cap - say if a resistor is tied across it in paralell.
Finding parts that are physically compatable might be hard. Not an issue if you don't care if it looks original on the inside. Electrical substitutes should be no problem. Of course all tube equipment runs at higher voltages inside so you have to be careful of that for safety.
Hope some of that helps.

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Post: # 3815Unread post Steve E.
Sun Nov 16, 2008 1:46 pm

I definitely don't care if it looks the same on the inside. I am starting to get the feeling that I can handle this, but I guess I should research how to minimize the chance of electric shocks.

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Post: # 3816Unread post blacknwhite
Sun Nov 16, 2008 4:52 pm

Steve,

Yes, You Can!

For a long time, I "restored" amps by blindly replacing all capacitors & tubes, and almost always resulted in success (except for a couple of "tough cases"). I just read the values off the capacitors & tubes (using a combination of common sense, and info from the web on how to read values on older capacitors), ordering replacements from http://www.tubesandmore.com, and replacing. Like Cuttercolector mentioned, there are different kinds of caps - 2 important functional categories are electrolytic capacitors where polarity DOES matter (greatly!), and non-electrolytic wax-coated brown paper ones which don't.

If that's the way you choose to go, then When blindly replacing all caps, 3 things you need to know about each cap being replaced: (1) is it electrolytic or not (i.e. does polarity matter)? This as far as I remember is just the metal-cased "can" caps in the power supply, which are actually 3 or so electrolytic caps in one container, with 4 terminals. I am not at all, sad to say, "authentic" with the looks of the inner components. I just replace them with modern equivalens, no worries about inside appearance (but am meticulous about maintaining outside appearance). PErsonally, I replace can caps with several separate modern smaller electrolytics of same values (there will be 3 or so values written on side of each can cap - be sure and remember which wires go to which of the 3 values!).

Second and third things you need to know about each cap are (2) capacitance value (unit = farads, or microfarads) (need to get an exact or very close value in your replacement), and (3) maximum voltage handling capacity (unit = volts) (need to get an equal or higher value in your replacement).

Webster-Chicago made AWESOME bomb-proof gear atleast up thru the mid- 50s, built like STEEL TANKS in the heart of the US steel industry, Chicago! Their record players & other audio gear from that period is bada$$, imho! Even their 45 rpm inserts were made of steel. I use those exclusively in the 1949 jukebox which I switch back & forth between 78 rpm and 45 rpm from time to time (small spindle).

- Bob

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Post: # 3817Unread post Steve E.
Sun Nov 16, 2008 5:24 pm

Thanks for the feedback, cc and b&w!! Oh, good.

Indeed, great machines.

The other Webster Chicago wire recorder that I have--the one restored by a guy named Mr. Science in Seattle, circa 1993--has been running great ever since that time. Even then, the motor worked fine (which is more than I can say for my Teac open reel tape decks from the early 80's). The fidelity is astounding, especially given that it is reading magnetism off a wire about as thin as a human hair. Yeah, there's some "wow", noticeable on music recordings, but surprisingly low considering that the technology includes 1) no capstan and 2) a recording/play head that moves up and down, serving the same function as the, uh, zig-zagger (spooler?) on a sewing machine or a fishing reel. Astounding? Well, better than typical AM radio, let's say that.

Plus, they look beautiful. Great art deco design. Here's one on the West-tech site:



Image

My new one is prettier, with reddish-brown-painted metal.

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Post: # 3851Unread post grooveguy
Sun Nov 23, 2008 6:05 pm

Steve: Do you have documentation on this recorder? I think I have either a Sam's or other service manual, maybe even original Webcor paperwork. Let me know if I can help.

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Post: # 3858Unread post Steve E.
Mon Nov 24, 2008 12:33 pm

I have the little consumer instruction guide, which has a schematic, but I would LOVE scans of any other maintenance guides! thanks in advance.

My old one (similar to the one pictured above) is a model 80, not a 180-1. I was wrong. A notable visual difference is the timing dial under the takeup reel. My new one is a 288-1, as pictured below:

ImageImage

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Post: # 3859Unread post grooveguy
Mon Nov 24, 2008 1:04 pm

Let's see what I have and I'll get back to you. Stand by!

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Post: # 3860Unread post cuttercollector
Mon Nov 24, 2008 1:07 pm

One other thing to note about wire recorder fidelity.
The quality of actual recording via "line in" on that silly 3 pin jones plug (if you can find a connector) is far far better than the included crystal mic, even if it is rebuilt to work. This holds true for most supplied mics with tape and disc recorders from the 40s - 60s as well as wire. Although people love this sort of mic for blues harp through a small amp, they are pretty peaky and roll off in the bass and to some degree on the high end as well. I remember transfering some excelent sounding late 78s from the 50s to wire via the line/"radio" in and being amazed at the fidelity.

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Post: # 3861Unread post Perisphere
Mon Nov 24, 2008 1:39 pm

I still have my dad's 80-1 he'd bought 60 years ago. It's needed a fair amount of electronic work over the years for caps and resistors that went off spec, and the power transformer replaced (never fear, I saved the original but haven't the bux to get it rewound). Still going like always!

For those of you new to them and wondering, the 3 pin input jack is wired with the top pin ground, the center pin the mike level input, the lower pin line level input.

Another big difference between the 80 and earlier models, versus the 180 and later units is (IIRC) beginning with the 180, the newer machines had removable takeup drums. The older models don't.

I also have a 180 model whose mechanism I've fixed, but I've never had the time or resources to recap/restore the electronics in. The spacing of turns of the wire (or think of this as how many turns of wire to each time the head either goes all the way up or all the way down) are closer together on the 180, I think to more closely mirror the spacing thereof characteristic of those recorders offered by other manufacturers, the ones that had the larger takeup drum that turned at 78 rpm (and often doubled as a record player).

One thing I read on a Webster-Chicago tribute site, is that the 288's deeper cabinet was supposed to enhance bass response of the internal speaker. (I hope it helps keep the electronics from overheating so readily; my 80 could never be operated for much longer than an hour!)

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Post: # 3863Unread post Simon
Mon Nov 24, 2008 3:44 pm

Happy to learn something new.
Wanted: Stylus for Presto, Mono heads Grampian, Fairchild, Presto, Fairchild 740 lathes, Presto 8n, 8d 8dg lathes or parts or Presto or wot ever recording Amps, PM me what you have for sale.

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Post: # 3864Unread post cuttercollector
Mon Nov 24, 2008 6:20 pm

It is amazing how many of these are still around. I had one of the dictation style machines with the metal cabinet pictured on on of those links. Now I have the typical one like on Gib's site. I was helping someone with one of these once who was trying to transfer to cassette at the time.
The machine's main filter cap exploded!
I think, if these are like their early tape machines that came just after them, they had an odd push pull 6SN7 triode output stage. This tube is almost never used for that.

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Post: # 3875Unread post Simon
Tue Nov 25, 2008 6:36 pm

Happy to learn something new.
Wanted: Stylus for Presto, Mono heads Grampian, Fairchild, Presto, Fairchild 740 lathes, Presto 8n, 8d 8dg lathes or parts or Presto or wot ever recording Amps, PM me what you have for sale.

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Post: # 3883Unread post Perisphere
Wed Nov 26, 2008 8:47 pm

cuttercollector wrote: I think, if these are like their early tape machines that came just after them, they had an odd push pull 6SN7 triode output stage. This tube is almost never used for that.
That is a most unusual application for the 6SN7.

If the 288 has the same electronics as the 180, it will have the 6SN7 for power amp too. (My 80 has the earlier circuit using a 6SJ7 pentode for mike level input or the first gain stage for playback, a 6J5 triode for line level input or second gain stage in playback, a 6V6 beam tetrode for bias oscillator or single-ended power amp in playback, and a 6X5 full wave rectifier.)

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Post: # 3971Unread post Steve E.
Thu Dec 18, 2008 10:08 am

Well! After days of work, I replaced all the caps and tubes.

I turned it on, and voila!! Sound!!!

Only thing is, it doesn't yet sound as good as my other one. When playing back at lower levels, the sound is fuzzy and a bit distorted---kind of like 8-bit sound, or sound through a punctured amp speaker. BUT....if I turn the volume up all the way, this problem disappears and the thing sounds glorious. Also, at lower levels it's the quieter things that have this problem, but louder things tend to sound OK.

Any initial guesses as to what this might be? Bad tube? Blown resistor? crappy volume pot? Again: Loud stuff, great, quiet stuff, bad, and the same reels sound better on the other machine.

I should note that two of the filter caps I used are 20 to 25%% higher in mFs than indicated on the schematic. (25mFs replaced w/ 30 and 40-->50)

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Post: # 3972Unread post cuttercollector
Thu Dec 18, 2008 1:03 pm

2 guesses. (well... 1 1/2) Nothing specific. I think you may have a "weak side" to your push pull amp (if it is push pull in these like their early tape machines). Or, the waveform is not being amplified symmetrically or at all on one side due to rectification of the signal somwhere through a poor connection acting as a diode in the signal path. If you looked at it on a scope at lower volume you probably have half your waveform missing or almost missing. A bad speaker can do this too if the voice coil is stcky and rubs a bit. At higher volumes the signal overcomes the resistance and it moves more or less as it should.
So, in the amp you might want to check all components associated with the phase inverter, just before the output and also make sure that one output stage is not nearly dead while the other is ok. ("push" but no "pull")
Again, any poor connection in the signal path can act as a diode and rectify the AC audio signal but when you turn it up the higher voltage overcomes this diode action and passes through normally.
One last amp scenario. This could be even more likely. A change in a component that sets the bias for one of the tubes could have a stage (again, probably the output) operating in a non linear portion of it's curve.
Check to make sure the output coupling capacitors are not bad. Beware if the output tube's plates glow red in a darkened room. DC is leaking through the coupling capacitors from the previous stage plate to the grid of the tube. This will ruin the tube.
Not sure how that would be worse at lower volume levels though...

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Post: # 3989Unread post Perisphere
Sun Dec 21, 2008 12:28 am

Does this same phenomenon exist when the machine is connected to an external speaker or amp and speaker?

My hunch is, the speaker is faulty. Dad's machine had such a buzzy quality when I was young, and through the 1970s it got eventually where there was no real sound from it. By 1980 it did not produce sound at all despite the voice coil showing continuity. No big deal as I had cables that permitted me connecting it to other equipment.

In January 1983 I did something rather ambitious, and sacrificed the voice coil from a perfectly good 3X5" speaker. I saved the original speaker cone, and removed the faulty voice coil from the gap. The problem? The voice coil wire had gradually fallen off the coil form over the decades.

I managed to fit the coil and spider from the 3X5 speaker into the gap, attach the leads, and reattach the original cone over and onto this new coil/spider assembly. Shimmed things into position with bits of notebook paper, and glued the works together with Duco cement IIRC!

Dad almost totally freaked out when I told him what I'd done. He thought I'd likely destroyed any resale value the machine would have had. (I told him I'd never sell it.) I then turned on the machine and let him hear it with my speaker repair job all done. He was dumbstruck....he said 'Why, it didn't sound that good when it was new!'. (So apparently it was buzzy even when he'd first had the machine.)

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Post: # 4058Unread post Steve E.
Sun Jan 04, 2009 5:05 pm

Perisphere wrote:Does this same phenomenon exist when the machine is connected to an external speaker or amp and speaker?
I finally tested this, and......
Perisphere wrote: My hunch is, the speaker is faulty.
BINGO! External sounds great, it turns out. yayyy, I successfully recapped after all!
Perisphere wrote: Dad's machine had such a buzzy quality when I was young, and through the 1970s it got eventually where there was no real sound from it. By 1980 it did not produce sound at all despite the voice coil showing continuity. No big deal as I had cables that permitted me connecting it to other equipment.
Are you talking about your Dad's Webcor machine? If so, it this basically my best option for fixing this speaker? What to do?

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Post: # 4059Unread post grooveguy
Sun Jan 04, 2009 5:26 pm

It amazes me that a wire recorder can sound as good as it does. The Webcor head was hands-down better than the Shure heads supplied with the Crescent decks used by Sears, Majestic, etc. (where the takeup drum doubled as a 78 r.p.m. turntable). The Webcor heads had a sufficiently wide face that low frequencies were reproduced well, even at a speed of 24 ips (the faster the speed of tape - or wire - the more that playback head geometry influences LF response). Toward the last, Webcor sold a replacement head with a short gap, which extended high-end response to 10kHz. The older heads cut off somewhere between 5k and 7k. The only think I ever found lacking in a wire recorder was a fast-forward function. What a pain it was to wait half an hour to hear the second old radio show recorded on a 1-hour reel.

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