Was this the "cats whisker" type?

In the late 60's, as a kid, I used a diode. About 20 years ago I made a few with a cat whisker ... much more difficult to tune but fund to try ... and they do work!

 

Get a current copy of WRTH - World Radio TV Handbook.

View attachment 347416

Great ... didn't know they still published anything like this. Thanks!

 

My 2C. You will not be happy with that mighty midget radio design. The one I posted above #18 is more more likely to work and you can paint it up to match any thing you like.

Thanks ... I will take a good look at it. I am just starting to gather parts ... just one of those project that has been in the back of my mind forever. I decided I need to make time for "fun" projects ... I am not getting younger (as my wife reminds me)!

 

Thanks ... I will take a good look at it. I am just starting to gather parts ... just one of those project that has been in the back of my mind forever. I decided I need to make time for "fun" projects ... I am not getting younger (as my wife reminds me)!

The one I linked to will run on easy to get batteries.

 

Hello,

Many old books can be found on the "bookshelve" of the worldradiohistory site:
https://www.worldradiohistory.com/Home-Book.htm

Bertus

 

Certainly a lot of responses here. This is about the original topic:: That capacitor, 0.5 mFd, was a paper capacitor, no way an electrolytic cap!! The other components would not be a problem except for the tube and the coils. The TS can wind their own coils "fairly easily", a similar material that could be the right diameter, about 1 1/4 inches.

Likely true as the value seems too low for a polarized cap and the end band was for inner or outer foil for old paper types.

 

OK ... so one person said the .5 was electrolytic and you say it is not. The drawing does not indicate electrolytic but I see in the picture, the cap has a stripe at one end. How can I tell if it is or is not?

Thanks for answering the question. I already know I want to build a SW tube set ... I know I want it to operate on batteries. I figured this was a simple design to play with ... thanks.

He's very likely correct about the .5 cap. It's been a long time since I played with the old stuff.

 

Hello,

Many old books can be found on the "bookshelve" of the worldradiohistory site:
https://www.worldradiohistory.com/Home-Book.htm

Bertus

WOW ... lots and lots or reading !!!!!! I love old tech so a goldmine for me! Thanks

 

Start with random codes with increasing lengths in this order, including the set you have mastered:
E, T
I, A, N, M
S, U, R, W
D, K, G, O
H, V, F
L, P, J
B, X, C, Y
Z, Q, CH

There are a set of QR- codes that are also used as morse shorthand.
We Used to send QRL as 'Use left foor" as an abuse of its real meaning.
On a side note, I was not aware some things shown in this video, quite intersting if true!

https://www.reddit.com/r/morsecode/comments/1ft8vup

 

Something in the back of head says they were similar when I first saw them.

 

Hello,

For info and a forum for old radios can be found here:
https://www.radiomuseum.org/
https://antiqueradios.com/

Bertus

 

So, I got the bug to build a one tube regenerative radio.

I found a design from 1940 that looks promising.

Question ... what capacitors do I use?

There are only three ... a .0001 MFD ... a .0002 MFD ... and a .5 MFD

The first two are Mica and the third I am guessing was paper.

The radio should cover the SW bands ... so say 1.8MHz to 30 MHz

What is the modern equivalent caps?

I am also having a bit of problems finding the choke ... I am thinking maybe I can wind one? Might also be a bit of a rabbit hole ... started reading about RF winding (Pi winding) and litz wire and ....

Thanks so much ....
View attachment 347361View attachment 347362View attachment 347363

Give ebay a spin, they often have stuff like this:

6 NOS Vintage .5 uf 600v Gudeman Tube Amp Capacitors XFS-187 New Old Stock

 

Re: Capacitors.
Follow what C-5 is connected to,
One side, the Positive, or "Non-Striped" side,
is connected to 45-Volts-Plus, though a Pot, ( the Regeneration-Control ).
it then continues on to to the Audio-Transformer,
and the negative, or "striped-side" goes to Ground.

It may well be that in 1940 they used "Paper-Capacitors" in Power-Supplies, I really don't know.
That may have been good-enough with Battery-Power.
But it seems to me that a
modern, larger, Electrolytic-Capacitor would work even better in that application,
possibly with the addition of a 100nF-Ceramic-Capacitor just for good measure.

I also think you might like to check-out the PDFs that I provided
covering the assembly and usage of a Knight-Kit-Ocean-Hopper-Radio.
Mine had excellent performance back in the mid '60's, when I was around 9-years-old.
It used 2 very-common-Tubes, plus a Tube-AC-Rectifier, and an L-C-Power-Supply,
and was designed to Power a built-in 4"-Loud-Speaker, or Headphones, ( which I never got ).
This was my first "official", "real", DIY-Project that I got for Christmas 1966.
.
.
.

 

Give ebay a spin, they often have stuff like this:

6 NOS Vintage .5 uf 600v Gudeman Tube Amp Capacitors XFS-187 New Old Stock

What a ripoff! $80, foo on that.

 

Re: Capacitors.
Follow what C-5 is connected to,
One side, the Positive, or "Non-Striped" side,
is connected to 45-Volts-Plus, though a Pot, ( the Regeneration-Control ).
it then continues on to to the Audio-Transformer,
and the negative, or "striped-side" goes to Ground.

It may well be that in 1940 they used "Paper-Capacitors" in Power-Supplies, I really don't know.
That may have been good-enough with Battery-Power.
But it seems to me that a
modern, larger, Electrolytic-Capacitor would work even better in that application,
possibly with the addition of a 100nF-Ceramic-Capacitor just for good measure.

I also think you might like to check-out the PDFs that I provided
covering the assembly and usage of a Knight-Kit-Ocean-Hopper-Radio.
Mine had excellent performance back in the mid '60's, when I was around 9-years-old.
It used 2 very-common-Tubes, plus a Tube-AC-Rectifier, and an L-C-Power-Supply,
and was designed to Power a built-in 4"-Loud-Speaker, or Headphones, ( which I never got ).
This was my first "official", "real", DIY-Project that I got for Christmas 1966.
.
.
.

I will definitely look at your design. Might be a more proven design. This one came from Popular Mechanics ... not even an electronics magazine. Thanks

 

It's not "my" design at all, only suggestion(s) as to modern replacement part(s)
for some questionable, and sometimes finicky, antique-designs that are no longer produced.

If "Paper" was a really good insulating-layer for a Capacitor,
they would still be making "Paper-Capacitors".
Paper is what got the job done, at a reasonable cost, and with the available materials of the Era.

Old Mica-Capacitors, on the other hand, are truly high-performance-items,
and are still produced,
and are likely still working exactly as they did when new, almost ~100-years ago.
.
.
.

 

I will definitely look at your design. Might be a more proven design. This one came from Popular Mechanics ... not even an electronics magazine. Thanks

.
Popular-Science, Popular-Mechanics, and Popular-Electronics Magazines
were very "Popular" from the late '40's right up to at least the late '80's.
I'm not totally sure, but I think they were all produced by the same Parent-Company.

For the right amount of Money, ANYONE could get a
"Featured"~6-page Write-Up-plus-Cover-Art done on just about any crazy new "Idea".

They had lots of quality-useful-stuff, plus
plenty of government-Propaganda at the same time.

My Dad had subscriptions to both Popular-Science, and
Popular-Electronics Magazines since "forever",
so naturally, I got to read them too.

But the BEST was MAD-Magazine,
with it's excellent Satirical-Writing, and the best Caricature-Artists the World has ever known,
MAD started in 1952, but unfortunately, started seriously going down-hill in the early '80's,
but still has dedicated-Fans and extensive YouTube-Tributes in 2025.
.
.
.

 

If you have money to invest this is likely the best tube set you can buy.
It employs 23 vacuum tubes,
https://en.wikipedia.org/wiki/R-390A

! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !

ak

 

! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !

ak

Still likely used (from a few Apocryphal reports) as an emergency backup, backup receiver In the Navy today for some missions as it's nuclear EMP proof with all of those tubes. We had racks and racks of solid-state modern HF radios and one R-390A for shortwave radio stations for music or CW codes from all-mighty.

 

Back to that ).5 mFD capacitor: The concept was explained that the outer foil would tie to the ground, to shield from hum and noise pickup. Paper caps made with the right oil will last a long time if used within their ratings. BUT they could have problems. then plastic film capacitors were developed when reliable plastic film could be produced. And they were cheaper, so they took over. Now we have silver-mica capacitors which are still better but cost quite a bit more.