ANTIQUE-RADIO-LAB

Antique Radio Forum for Collectors antique-radio-lab.forumotion.com
 
HomeHome  RegisterRegister  FAQFAQ  SearchSearch  Log inLog in  

Share | 
 

 How you got started building crystal sets

View previous topic View next topic Go down 
AuthorMessage
NT9K

avatar

Join date : 2011-12-14

PostSubject: How you got started building crystal sets   2011-12-14, 4:58 pm

I first got interested in crystal sets after I saw an old war move. The POW's had a crystal set they made and it got me to thinking how they might have been able to build it, while being prisoners of war. I went online and discovered foxhole radios and started researching different designs. I found one that used a razor blade and pencil lead detector and decided to try building one. Sure enough, it worked right off the bat. I was able to pick up 2 strong local stations with it.

From there, I went on to modify my foxhole set with an air variable capacitor and swapped out the razor blade, safety pin and pencil lead with a 1N34A diode. This nearly doubled my volume, but still only those same 2 stations could be heard. One of them is real close to me, so next I learned to build a trap. The trap completely eliminated the nearby station and allowed me to pickup a 3rd station that I couldn't hear before.

Now I have been studying DX crystal sets and have been scrounging parts to make a much better set. I've just about got all the parts now and am ready to start building. I've already learned a lot, but I still know I have lots more to learn. For the meantime, I have been listening to the broadcast band with my Kenwood TS-870 Ham Transceiver. It picks up AM DX really well and I usually listen to WSM 650Am from Nashville TN every night during the dark hours. I just started to listen to KMOX 1120 from St. Louis. During the night hours and early mornings, they play old time radio shows like Fibber and Molly, the Shadow, Jack Benny and others.

It's fascinating to me, that radios can be built at home, that require no power source and still perform so well. It's interesting learning about crystal sets and so far everyone I've met has been very kind and willing to help teach me. Besides that, it's a lot of fun!

_________________
73, Bill NT9K
Melbourne FL
[You must be registered and logged in to see this link.]
Back to top Go down
Krystallo



Join date : 2011-12-15

PostSubject: Re: How you got started building crystal sets   2011-12-29, 4:34 pm

Hey All,

After 2 failures, my first SUCCESS was with the Radio Shack 28-207 when I was around 8 years old (I just turned 51).I can't say HOW many of those I bought over the years,if nothing else for parts and earphones, etc. I didn't know of any mail order houses way back then.

MANY sets followed over the years, most being built within the last 10 or 15 years.Among my favorites was a SW crystal set I built while stationed in the Army in Germany. I used to listen to the Voice of America from Greenville ,NC nearly every night. The boys in the barracks were amazed I could do this w/o batteries or electricity.

More recent xtal radios included 1920's sets -either from scratch or rebuilds, and VERY high Q/ BIG litz / sound powered /"competition" grade sets.

More recently I have actually taken a step back and "gone back to my roots" by trying to optimize SOLID wire sets. My latest solid wire rig is the "KMT" (Krystallo Mini Tuggle).The det section (by far the hard part) is done and tested good. The ant section is almost ready.

I have many parts in stock and will be able to build lots of radios for the foreseeable future without having to buy much of anything.

My dad built at least one crystal set as a kid and he is my inspiration in much of this.

To me there is something magic about passive set dxing. And IMHO the audio (especially music) from a crystal set can't be beat by any powered set.

K
Back to top Go down
ve1arn
Moderator
Moderator
avatar

Join date : 2010-11-23

PostSubject: Re: How you got started building crystal sets   2011-12-30, 3:51 am

Krystallo, I know what you mean about the passive stuff. I share the interest for sure.

Can't remember exactly what age I was, but I got the rocket radio for a birthday gift and couldn't get over it. Put the clip on any metal and BINGO, you can hear things!

Being the complete noobie at it, I assumed that the rocket shape had something to do with it, especially since the little ball on the nose determined what you listened to, and was afraid to try an open it in case I busted something. Boy, have I come a long way! Laughing

Dunno whatever happened to it, but I sure miss it.

Happy New Year gang.................. Bob
Back to top Go down
Krystallo



Join date : 2011-12-15

PostSubject: Re: How you got started building crystal sets   2012-01-24, 12:50 pm

Hey Bob,

Yup,
I've messed with a few rocket radios. fun little sets, especially when you do the mod on the coil per crystalradio.net.

K
Back to top Go down
Cliff Jones
Site Administrator
Site Administrator
avatar

Join date : 2010-11-22

PostSubject: Re: How you got started building crystal sets   2012-01-24, 9:59 pm

I would love to get just the coil + slug from a scrap rocket radio. But that just wishing at this point,
There is a ton of schematics on the web for crystal radios. I even hooked up a 12 inch speaker with audio transformer, as a replacement for the earphone. This was back in 1958 as a teen, and it worked pretty good as there were a few powerhouse stations in the greater Los Angeles basin. One circuit used a second detector to create a low voltage, that had enough power to run a audio transistor as an amplifier. No batteries needed. I added a variable cap to get the weaker stations.

Strange as it sounds I never built a successful fox hole radio as I had no knowledge of electron principles or an earphone that worked and of course no solder or iron. I tried following the diagram off of a cub-scout book.

_________________
I'm a Science Thinker, Radio Tinkerer, and all around good guy. Just ask Me!
Back to top Go down
Krystallo



Join date : 2011-12-15

PostSubject: Re: How you got started building crystal sets   2012-01-25, 11:48 am

Hey Cliff,

Yes, I've seen those "dual" crystal sets (one tank to provide DC and another tank for tuning stations). Never built one though.I heard they MAY require separate antennas AND separate grounds at times.

Over the years there has been quite a bit of hoopla over "Foxhole" (razor based) sets.I have built several and they can be a real BEAR to get working , especially if you don't use pencil lead as the cat's whisker (pencil lead makes these detectors work maybe 25 to 50% easier, but they can still be touchy, even WITH the pencil).

Razors also seem to like BIG STRONG signals to "kick" them into action.GI's used razors because they had NOTHING else. I'm sure if they had access to ANYTHING else they would have ditched the razor for some thing more stable (ie galena) in a second.

FWIW, my crudest set was built on a wooden strip off a wine box using only a knife , flame and a rock as tools. The coil has a number of taps and is "doped" with Wrigley's Spearmint gum (which would have been available from "C" rations). This stuff gets rock hard over time.I did it the "tough" way, using only a safety pin for the whisker. It DOES work, but is VERY touchy to get working correctly.



Don't get me wrong ,these type of "dissimilar" detectors CAN be a LOT of fun to play with IF (IF!) you know what difficulties to expect ahead of time.

But IMHO they make dismal FIRST projects which may not work right (or at all) and could turn off potential crystal set builders that probably had an otherwise "good" working set, had they tried a DIODE FIRST. I ALWAYS suggest building ANY set with a diode first and THEN mess around to your heart's content with galena,pyrite, razors, copper oxide, iron oxide, etc, etc.

FWIW,I once accidentally built a detector that used two ultra fine copper wires that simply crossed in an ultra light contact ( I called it the "Cu Cu" detector because it was kind of crazy that it even worked). None of the "gurus" could explain exactly how it functioned, it was proposed that one wire had finger oils on it or slight oxidation causing it to behave differently than the other wire.It was ULTRA touchy to get working and the audio was also always highly distorted .NOT good listening ! I've seen a number of obscure plans for some bizarre dissimilar detectors over the years. Although fun to mess with, I always wind up coming back to "conventional" mineral detectors ( galena, etc) or diodes in any "serious" set.





K
Back to top Go down
Cliff Jones
Site Administrator
Site Administrator
avatar

Join date : 2010-11-22

PostSubject: Re: How you got started building crystal sets   2012-01-25, 12:00 pm

One type I have heard of is a coherer, it is a glass tube filled with metal filings, was used as a detector to receive spark gap transmissions. I wonder how it would work for commercial radio signals?

I guess also you would have to tap the tube to get it to work from time to time.

_________________
I'm a Science Thinker, Radio Tinkerer, and all around good guy. Just ask Me!
Back to top Go down
Krystallo



Join date : 2011-12-15

PostSubject: Re: How you got started building crystal sets   2012-01-25, 5:14 pm

Hey Cliff,

The coherer seems like it was a clumsy device. I'm not really sure if they EVER got it to work very well. The hammer DID have to "restore it" on every dit or dah.They were also prone to errors/false signals. They were better than nothing, but...

I would think that the radiomen of the day were probably very glad to see anything else be developed (magnetic detectors,electrolytic detectors, crystals etc).

K
Back to top Go down
FrankB
Moderator
Moderator
avatar

Join date : 2010-11-22

PostSubject: Re: How you got started building crystal sets   2012-02-20, 11:41 pm

At about 6-7 I started out, (with the help of my Mother in soldering) building the famous Rocket Radios from kits at the 88 cent store.

Then I progressed to the Cub Scout/Boy Scout radio Galina detector catwhisker kit, which worked quite well.

I have tried making some Carborundum Detectors, without too much success. I have used many germanium diodes also. I saw an article recently about the fact the new germanium diodes were not as good as the old ones.

I have a big batch of NOS 1N21's I have yet to try. They should work fine, as they are about WW2/ Korean war vintage; which I am still trying to find the holder for them I picked up years back.
(I just got them in the latest batch of 70,000 (+/- a few thousand)tubes I bought.)

Cliff, IIRC I may have an extra loopstick antenna I salvaged a few years back you are welcome to, if you still want one.

Modern Radio Labs has a HUGE amount of information available on the xtal sets. Several evenings worth of reading, and several years Shocked worth of experimenting, if you want to make all the circuits. My best friend jay, (SK) Sad Sad had all the pamphlets and his wife gave them to me after his passing.

Also Lindsey publications has a couple of books on Xtal sets, IIRC.
HTH
FrankB


Back to top Go down
Cliff Jones
Site Administrator
Site Administrator
avatar

Join date : 2010-11-22

PostSubject: Re: How you got started building crystal sets   2012-02-21, 12:30 am

FrankB, Is it a loop-stick from a rocket radio?

Or pocket size crystal radio type?
even if not I would still be intrested, I can pm my address.
I am deliberating on buying some of the ceramic ear pieces from online source for about $3 each as that was the type used in rocket radios. That was from mouser electronics, the cheapest ones I saw anyway.

_________________
I'm a Science Thinker, Radio Tinkerer, and all around good guy. Just ask Me!
Back to top Go down
FrankB
Moderator
Moderator
avatar

Join date : 2010-11-22

PostSubject: Re: How you got started building crystal sets   2012-02-21, 1:13 am

All I know is its a AM loopstick antenna coil with an adjustable core, similar to the ones used in the Rocket Radios. The same type is used in many of the xtal radio projects. I have found in books
Back to top Go down
Cliff Jones
Site Administrator
Site Administrator
avatar

Join date : 2010-11-22

PostSubject: Re: How you got started building crystal sets   2012-02-21, 11:08 am

It may be a antenna coil off either a car radio or tube set also as some of them didn't use a variable capacitor. If it has a small knob on the top of the shaft it could well be from a rocket radio. Yes I would be intrested in it anyway.
PM sent.

_________________
I'm a Science Thinker, Radio Tinkerer, and all around good guy. Just ask Me!
Back to top Go down
FrankB
Moderator
Moderator
avatar

Join date : 2010-11-22

PostSubject: Re: How you got started building crystal sets   2012-09-12, 10:27 pm

I just found a bunch of 1N60 diodes in Sylvania OLD boxes in the tubes I am sorting thru.
They should be fun to play with when I get time.

I ran into one of the kids I had hired to work at The Electronics Shop in Olympia during the 80's.
We got to talking and I never realized just how impressed/ freaked out he was with my electronic talents.
We had no radio to listen to in the store, so I took an old xtal off a junk computer board, a variable cap out of a scrap BCB set, wound a coil on a TP tube and hooked it all to my signal tracer.
We could listen to the local AM station, KGY on it.
He told me how much that 10 minute to make radio that didn't use any power impressed him. I was flattered and a bit overwhelmed. Embarassed

Of course, when I needed the signal tracer, I had to unhook it.

He went on to become a programmer for a ship builder last I heard of him.
Back to top Go down
razorradio



Join date : 2014-11-14

PostSubject: Re: How you got started building crystal sets   2014-11-14, 3:13 pm

My first crystal set that worked was a Radio Shack 10 in 1 that had a crystal set, a one transistor radio, and a transistor/diode detector radio in it.  It got faint signals from 30 miles away from probably 3 stations on a short antenna, 10 feet of lead-in wire and a 5 foot whip antenna--I got 5 stations when I put up a good antenna wire outside.

Another one that I really liked only got one station.  It amazed me that my only parts were a 1N60 diode and a piezo earphone!  It was clear as crystal and a station that I liked.  It was about 9 miles away and was louder than the original Radio Shack 10 in 1.

The next one I had was a MRL-2 built by Elmer himself.  A great radio that still works well and actually gets DX in this location. I can easily get stations 300 miles away in the winter with a 45 foot wire antenna.

I built a razorblade radio from plans in a book from the 50's in our gradeschool library.  I remembered the plans and looked it up when I went back to have a Spaghetti Dinner that my cousin invited me to. He was still in that school when I was in high school.  It worked surprisingly well.  I listened to that for about a year.  I think I got the original 3 stations that I got on the 10 in 1.
Back to top Go down
 
How you got started building crystal sets
View previous topic View next topic Back to top 
Page 1 of 1
 Similar topics
-
» How to get started as a palm reader
» a flood and falling building
» Building Permit
» Wedding in old dorm building
» Blue and White Crystal

Permissions in this forum:You cannot reply to topics in this forum
ANTIQUE-RADIO-LAB :: Radio Repair Bench :: Crystal Radios-
Jump to: