PAPER CAPACITOR VALUES

Radiosmoker · **Posted:** Nov Fri 15, 2019 2:43 am

devilsmist wrote:

pixellany wrote:

mfd is an obsolete from---as is mmfd (meaning micro-micro Farad.

What do you mean obsolete :shock:

That is what I learned and what I still use.

DM

What they mean is, to be correct when it comes to electronic parts, if it has the obsolete markings on it, you are not supposed to use them even if they are still good. :roll:

Old methods are no longer used because everyone has to be on the same page (so to speak) don't you know?

I AM NOW IN CONTROL, I ADJUST THE Vertical and HORIZONTAL! MU-HAHA!!!

HAMmer · **Joined:** Sep Sat 28, 2019 2:05 pm **Posts:** 71

I may have to give the stripes a try,I have re stuffed a few capacitors on old hallicrafters once or twice , maybe i will try something different this time !

egg · **Posted:** Nov Fri 15, 2019 3:15 am

Yup... insulated solder terminal strips mounted underneath the chassis is okay.

ebay: https://www.ebay.com/sch/i.html?_nkw=so ... ps&_sop=12

Greg.

AJJ · **Posted:** Nov Fri 15, 2019 3:18 am

HAMmer wrote:

thankyou i may just have to snag that it is cheap enough ! , i did find the manual online and printed it off ! . The one i am worried about is the electrolytic that is on the top side of the chassis . It is a 20 20 40 mfd according to the manual , what would your suggestions be on that one . ?

If they're easier to get, you can use 22mfd and 47mfd.

HAMmer · **Joined:** Sep Sat 28, 2019 2:05 pm **Posts:** 71

thanks for the link i have been browsing ebay for the stripes, i was able to find all the capacitors and am now waiting . I am not sure if can post this question in this forum ,but while i am waiting for my other parts to show up i am going work on the variable air capacitor. What are your suggestions for that, i think i am going to remove it from the chassis and soak it for a while its in need of good cleaning .

AJJ · **Posted:** Nov Sat 16, 2019 6:43 am

Digikey has several sizes. Search term: "terminal strips" (link below).

https://www.digikey.com/products/en/con ... l%20strips

As far as the tuning capacitor goes, I've never done more than just blowing dust off and vacuum. Then maybe a very light rinse with 1/2 oz. of alcohol with a very soft brush. Just to make it operational.

HAMmer · **Joined:** Sep Sat 28, 2019 2:05 pm **Posts:** 71

I will give that a try!

HAMmer · **Joined:** Sep Sat 28, 2019 2:05 pm **Posts:** 71

I found a multi section can capacitor its a 20 20 20 450 would this work ? the original is a 20 20 40

AJJ · **Posted:** Nov Sun 17, 2019 4:00 am

Maybe...

Are you talking about the $40 ones made by "CE Manufacturing" on eBay?

You still would have to add a second capacitor in parallel (20 + 20) to make that 3rd section "40" as the design calls for. What you probably can do, is to buy the 4-section (20, 20, 20, 20), connect two sections together to make "40."

egg · **Posted:** Nov Sun 17, 2019 4:49 am

Two of these...
22µF 450V Aluminum Electrolytic Capacitors Radial, Can 10000 Hrs @ 105°C $1.53 + $1.53
https://www.digikey.com/products/en?mpa ... W220S&v=10

and one of these...
47µF 450V Aluminum Electrolytic Capacitors Radial, Can 10000 Hrs @ 105°C $3.29
https://www.digikey.com/products/en?mpa ... 2W470&v=10

Total $6.35

Greg.

Panasonic ED series...
https://www.digikey.com/catalog/en/part ... &vendor=10

Or... try Sal who advertises on the right/hand column of this page→

http://www.tuberadios.com/capacitors/

HAMmer · **Joined:** Sep Sat 28, 2019 2:05 pm **Posts:** 71

yes they are the ones on ebay , I think i will just save the money and make my own . I think i am going to try eggs suggestion , When i go to construct this capacitor do i take the 2 22uf and and connect those to one terminal and then the 47 uf to the other am i understanding that correctly . and then the one terminal is a ground .

egg · **Posted:** Nov Sun 17, 2019 10:13 pm

Connect the three negative leads together and connect them to Deck aka Chassis "ground".

Here is a four-section replacement using Axial capacitors instead of Radials. In this example, the arrow points to the negative lead of the capacitor. (note: the crimped end of an Axial electrolytic capacitor is positive).

▲ photo: AlanBienlein.
viewtopic.php?p=2966174#p2966174

Your positive leads + are connected to resistors R15 and R14 as shown here...

Greg.

HAMmer · **Joined:** Sep Sat 28, 2019 2:05 pm **Posts:** 71

Cool thankyou i will try a post a pic of the capacitor i build before install . I am going through and marking everything labeling and drawing pics ext looking at the bottom end where the three terminals . I notice there is two positives going to the resistors like you where explaining but why add a third red wire in there or am i seeing things :shock:

s and i am taking it the brown wire going to the resistor is the ground wire .

HAMmer · **Joined:** Sep Sat 28, 2019 2:05 pm **Posts:** 71

I just realized what the third red was for after going over the schematic :oops:

egg · **Posted:** Nov Mon 18, 2019 2:22 am

The original Multi-section capacitor can's metal body may have been the negative connection to the chassis... if there was no insulating washer/disc?

Citing "brown wire" is meaningless as there are no colors mentioned on the schematic...

Trace the "pathways" of your wires in the circuit, and identify the components that they connect to. Label all wires with masking tape flags.
Print out the schematic, and mark-it-up with (colored) Magic Markers.

The tube pinouts (pin numbers) are shown on the schematic

At times... non-used solder-tabs on the tube socket can be used as convenient anchor/tie points.

A schematic is not the real world→ viewtopic.php?p=3024622#p3024622

Greg.

Edit: 7Y4 rectifier diagrams, (some drawings are European).
https://www.radiomuseum.org/tubes/tube_7y4.html

AJJ · **Posted:** Nov Mon 18, 2019 6:12 pm

Agree with Greg...

More than once, someone here reported having automatically assumed all polarized capacitor negative connections go to the metal chassis, but turned out to be wrong. So always check how the radio is physically configured.

For this radio, the schematic suggests the metal chassis is "B-" and connects to the negative side of the 3-section capacitor through its metal body. You can verify if that's the case.

Also, I've learned to be "color blind" when looking at the wiring. Even if color of wires are marked on the schematic, wire's color may have faded or was replaced in the past. Always trace the actual connections.

HAMmer · **Joined:** Sep Sat 28, 2019 2:05 pm **Posts:** 71

So i was going to use terminal stripes , but i have decided to re stuff the capacitor . I have the can taken apart and am waiting for my capacitors to arrive in the mail . I got two 22uf at 450 and 1 47uf at 450 as egg suggested . I have been reading an artical from

https://www.tdpri.com/threads/restuffin ... rs.404905/. I want to try and recreate this.

When i go to make this i connect all negative leads together , now when i get to the positive leads do i connect the 2 22uf pos leads together and then the positive lead from the 47uf is separate am i understanding that or would that be incorrect thanks again the help is much appreciated

egg · **Posted:** Nov Wed 20, 2019 5:18 am

Connect the three negative leads together to make one negative connection.
Leave the positive leads separate and connect them as shown below.

Insulate the positive leads inside the can.
You will now have four leads exiting the can - - one negative and three positive.

Kevin's complete restuffing article can be found here...
http://crawlsbackward.blogspot.com/2013 ... itors.html

Greg.

HAMmer · **Joined:** Sep Sat 28, 2019 2:05 pm **Posts:** 71

thanks for the picture ! that helps me alot when i get it built i will try and post a pic !

HAMmer · **Joined:** Sep Sat 28, 2019 2:05 pm **Posts:** 71

quick question seeing how i am still waiting for parts to show up , when i go to ground the capacitors could i solder the grounds to one of the locking twist taps on the base of the old capacitor

PAPER CAPACITOR VALUES

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