Myth or Reality

[OperaHouse]

Things have been slow on this forum for a while so thought I would bring up this topic. Back in the early 60's I was just a little sprout reading Popular Electronics. They had this article about how a cheap (think this was an important parameter) AM loopstick transistor radio would stop working if it was turned upside down. I remember trying this and indeed it stopped working. I don't remember what they said was the reason for this. Of course they also had an article about how to make a Black Noise Generator out of a loop of wire connected to a BNC connector inside a Black Bean soup can. So is this true? Can't find an AM radio to try it. Or is this like some of the things I tell my wife and she tells me that never happened.

 

[IRstuff]

Any recollection of what the detector was? I recall my first crystal radio (c1970) and much of the literature at the time was still talking about cat's whisker detectors. A cat's whisker detector wouldn't work well upside down, but that should be pretty obvious. It's possible that the diodes of the time were's that much improved over the cat's whisker.

TTFN
faq731-376

 

[OperaHouse]

No, these were the 5 or 6 transistor AM radios coming from Japan in the 60's. I thought someone here would remember the Black Noise Generator project. After all these years I still haven't stopped laughing.

 

[IRstuff]

I had one of those transistor radios (not sure exactly what year, but certainly prior to 1971), but never had any problems with orientation. The only problem was melting the plastic case because I left the radio on the dash one day. Even then, the "cheap" Japanese radio kept on chugginy until it was finally replaced in the 80s. I don't recall any of my radios having an orientation problem.

TTFN
faq731-376

 

[Skogsgurra]

The 1N914 was available in the sixties. No cat's whiskers in commercial radios at that time.
It is a myth. Probably inherited from older days when orientation may have been a problem. Redneck and Mid-West thing, I would guess.

Gunnar Englund

http://www.gke.org

--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.

 

[Pud]

My first "wireless" was a diode (probably an 1N914, but it does not ring a bell), across the input of a pair of high impedance ex-military headphones. One wire extension to the bedsprings, the other dangling...
On the plus side, I lived about 3 miles from here Droitwich. A one station wireless for me!
H

www.tynevalleyplastics.co.uk

It's ok to soar like an eagle, but weasels don't get sucked into jet engines.

 

[dpc]

The antennas in these little radios are somewhat directional. Changing orientation could impact the signal strength. This may be how the legend got started.

 

[DHambley]

Operahouse, so it actually quit working when you turned it upside down? Wow. The only thing I can think of is that the base had to be near a ground for some odd antenna effect but, what do I know. that is indeed thought provoking.

 

[waross]

Radio won't work upside down? Black noise generator? Would these effects have been described in an April first issue of Popular Electronics?

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[Skogsgurra]

Haha! Didn't think of that. Very plausible.

Gunnar Englund

http://www.gke.org

--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.

 

[DHambley]

I worked at a firm years ago that was integrating Bose noise cancelling earphones to an aircraft system. We actually did joke about the earphones as black noise generators.

 

[VEBill]

1N914 - Puhleeze!! 1N34A or nothing!!!

 

[Skogsgurra]

Ge?

Gunnar Englund

http://www.gke.org

--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.

 

[mikekilroy]

yes, 1N34 germanium replaced MY cat whisker diode hooked to the bed springs antenna.... I miss moving the cat whisker around to get best signal tho.. ah the simpler days

 

[Skogsgurra]

Ge came before Si. So I guess that there was no galena in the radios of the fifties.

Gunnar Englund

http://www.gke.org

--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.

 

[Pud]

Just remembered ( I think!) - it may have been an OA47 germanium diode? Ring a bell anyone?

I also recall using two legs of a germanium transistor as well??

H

www.tynevalleyplastics.co.uk

It's ok to soar like an eagle, but weasels don't get sucked into jet engines.

 

[VEBill]

Lower Vf of Ge makes for a more sensitive "Crystal" (sic) radio.

The Radio Shack stores used to (c. 1970s-1980s) sell ten-packs of 1N34A Ge diodes - the primary market being for this exact purpose (xtal radios).

Interestingly, this city of nearly 450,000 used to have about a half dozen AM broadcast stations. Now - not one! AM Band is empty locally. No more crystal radios, unless made high performance for Xtal Radio DXing (an actual sub-hobby, seriously...).

 

[Skogsgurra]

XRxDX! That's to my liking. Slide Rules, AVO Tube testers and AM X-tl DX! My life is complete.

Gunnar Englund

http://www.gke.org

--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.

 

[IRstuff]

"No more crystal radios, unless made high performance for Xtal Radio DXing (an actual sub-hobby"

The crystal radio I made in junior high was capable of DXing, particularly if I used the dial hook as an antenna.

TTFN
faq731-376