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16B chassis — questions
#16

Yup. Definitely 16 and not 17.

--
Ron Ramirez
Ferdinand IN
#17

Thanks. A journey of a thousand questions begins with a single answer.

Regards.
#18

Attached is a clip from a 16b schematic that I found online.  

   

Having culled the forum for info, I still have a few questions (my xmas gift to you!):

1.  What is that thing with the two concentric circles in the lower-left quadrant?  A brief search of symbols online didn't reveal anything.  It does not appear in other 16b schematics.

2.  Re: the line-filtering caps directly off the mains:  Are these y-caps because they each go to a (common/chassis) ground?  Or are they x-caps because they bridge the mains (L-N)?

3.  Because the caps are upstream of the on-off switch, doesn't this mean that the chassis is always hot?  (I get the voltage divider and minimal current points, but why not move the switch upstream of the caps?  Or does this mean that you can get shocked if you touch the switch and a ground at the same time (if the wall plug is not spaded)?)

4.  Finally (for now) if you ground the chassis to earth (cold water pipe, radiator, etc.) does this eliminate any possibility of a shock from the chassis (per 3 above)?

5.  Another "finally": If I want to put a fuse in the power circuit, where should it go?

Thanks in advance,

Matthew W. Woodruff
#19

>1.  What is that thing with the two concentric circles in the lower-left quadrant?

Looks like a motor, the diagram may be for a set w/a phono.

>2. Are these y-caps because they each go to a (common/chassis) ground?  Or are they x-caps because they bridge the mains (L-N)?

Neither didn't have X-Y caps in '35. Can you replace them w/ x-y caps sure.

>3.  Because the caps are upstream of the on-off switch, doesn't this mean that the chassis is always hot?  (I get the voltage divider and minimal current points, but why not move the switch upstream of the caps?  Or does this mean that you can get shocked if you touch the switch and a ground at the same time (if the wall plug is not spaded)?)

Would really consider this to be a HOT CHASSIS. Typically that refers the set that have one side of the ac line connected directly to the chassis. This set up can be dangerous if the hot side of the line is applied to the chassis.
In your Philco the line is connected to the chassis but thru two caps so what you end up w/ is some small leakage current @ low voltage. This leakage can be eliminated by connecting an earth ground to the chassis. I don't recommend using the ground connection from the house wiring as it can be a source of interference via modern electrical devices.

>4.  Finally (for now) if you ground the chassis to earth (cold water pipe, radiator, etc.) does this eliminate any possibility of a shock from the chassis (per 3 above)?

Yes if you consider the leakage a shock hazard.

>5.  Another "finally": If I want to put a fuse in the power circuit, where should it go?

I'd put it on the switch side of the power transformer.

>6. What size fuse should I use?

2 amp.

7. Not quite sure what diagram you are using as I couldn't find any that had a motor associated w/it. Would think it's a 16B code 121 (table radio) I'm pretty sure this http://www.nostalgiaair.org/Resources/139/M0013139.htm would be the suitable diagram for your set.


GL

When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!

Terry
#20

Appears to be #62a-e on the Rider schematic.

What should the voltage of replacement caps be?

400/450 or so?

OK to use plastic film?

Do I need to be concerned about "ripple current"?

Sorry if these are naive questions, I was an English major.  (Happy to field any inquiries about Paradise Lost, however.)

Regards,

Matthew W. Woodruff
#21

450v caps are fine. No ripple current there it's over on 87.
If you wanted you could replace them w/all of them (in 62) 2mfd@450v electrolytics for simplicity sake.

> I was an English major
I'm lisdexsic. At least that how we say it.


GL

When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!

Terry
#22

I've merged the two 16b threads into one. please keep the questions for one radio together in a single thread.
Thanks!
#23

I used 2x0.01uF Y-rated caps on my 16, did just fne and not large enough to cause a shock.
You need Y-rated as those are caps (from lines to chassis), X cap goes only between the L and N.
The chassis will float at 60V but the equivalent is 20nF so the current is not bad.

People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
#24

7. Not quite sure what diagram you are using as I couldn't find any that had a motor associated w/it. Would think it's a 16B code 121 (table radio) I'm pretty sure this http://www.nostalgiaair.org/Resources/139/M0013139.htm would be the suitable diagram for your set. 

This may show most of the connections but check the upper output tube - it shows no DC supply going to the screen.  I believe it is triode-connected to the plate because the voltage chart shows the same voltage for screen and plate of each output tube.
#25

Yes you are correct. The 42 tubes are triode connect and both shoud have the plate and screen grid strap together.

When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!

Terry
#26

Sorry if I threw in any confusion... somehow I missed thread comments before posting.

16 is the basic model number, the letter suffix denotes the cabinet/console style. There were also some minor circuit variations between console and table models. The 16 also had early (5 band) and later (4 band) designs. Yours seems to have the earlier 5 band design, if I note the dial markings correctly.

What else do you have from the radio? Speaker, cabinet?

If you plan to restore, start by taking lots of notes, and study the schematic and chassis layout. It is a bit like learning your way around a new town

Plus, there is a lot of help available right here on the forums Icon_smile

I don't hold with furniture that talks.
#27

I found a .jpg of the schematic by using the internet machine, but an identical copy appears in "Most-Often-Needed 1926-1938 Radio Diagrams and Servicing Information," Breitman, M.N. (Supreme Publications, Chicago).

I think that I pulled it from Google Books.

From other information (Rider's, Perpetual Troubleshooters Manual, vol. IV), Model 16 Code 500 & 501 appear to be phonos.


Some more Q's:

As for the fuse on the mains: before or after the switch--or does it matter?

What is the wattage of this set?  I am planning to build a dim bulb tester this weekend and I understand that I need to know the wattage in order to select the proper light bulb.  (Incidentally, what happens when incandescents eventually go away?)

I got into this mess because I bought a 1948 Admiral TV in an antique store.  One look at that and I decided to tackle something simpler first.  All advice is appreciated.

Thanks and regards,

Matthew W. Woodruff
#28

Another tip off to which early or late is can between the if transformers and the tuning cap. Early models have a round can w/no holes in the top. Late models have a square can w/ 4 holes in the top to access the osc trimmers. Electrically the early model doesn't have a rf amp stage where the late model s do.

When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!

Terry
#29

>I got into this mess because I bought a 1948 Admiral TV in an antique store.

Like this one??  https://www.flickr.com/photos/42774321@N08/3938018239/

When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!

Terry
#30

Yes, but in much better physical condition. CRT lights up but no vertical deflection, some static from the speaker but it is still a long way from getting Howdy Doody.




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