My Crystal Set & 1 Tube Radio Reception Logs

[Dave-N2DS]

Hi DX friends.
Last weekend I spent time updating my radio reception log pages that I have on my website.
Perhaps some of you are interested in what can be heard with a crystal set or one tube
regen radio. Here are the pages.

Crystal Sets: http://makearadio.com/dx/amlog.php

1 Tube Radios: http://makearadio.com/dx/amlog-tube.php

I also updated my radio reception contest pages: http://makearadio.com/contests/index.php

The next reception contest is this coming summer. The winter contests aren't being held,
until someone can be talked into running it again.

73, Dave
N2DS

 

[ddsparxx]

Looks very interesting, Dave.

 

[Icangelp]

Dave. I enjoy your sites and remember ordering my first personal radio (crystal set) from one of the mail order catalogs that advertised in Boys Life.

 

[Tom Wells]

One tube regens rock!
Coupling the output through a 3k ohm to 8 ohm transformer and using high quality low impedance headphones
is an amazing improvement over old hard "cans", and a different thing entirely.

Everyone should build a few different versions to better understand rf.
Plug in coils for different bands, playing with coupling and using razor-edge oscillation as a wavy BFO.
Nothing in radio is more fun.

 

[BobOnTheJob]

Dave, Your crystal radio log is amazing! I built 1 crystal set from a kit around 1964...all I ever hooked to it for an antenna was about 15' of wire & a ground to the hot water radiator in my bedroom. I lived 3 miles from WSAI 1360/Cincinnati and it was by far the stronger of the two stations I ever heard on it...700 WLW was the other. It blows me away what a few simple parts are capable of--especially when you don't have 5000 watts breathing down your neck. At night, WSAI was directional and I was in the crosshairs, so there was no shot at any skywave...thanks for sharing!

 

[Schroedingers Cat]

Anyone have a Remco Caravelle schematic diagram? When the receiver and transmitter were both off the Caravelle would act like a crystal radio if the switch was in the transmit position, because I believe it was wired to act as an actual off air monitor when transmitting. You could hear stations that were more than about 30 mV/m when attached to a good ground.

I am curious as to how you get such weak signals with the crystal radios you built, Dave. I would assume that the multitude of inductors were acting as transformers to get the signal voltage above the 0.2-0.3 volt level for a Germanium diode to detect the signal, kind of a passive magnetic amplifier. My crystal radios (a Hearever Rocket Radio and some hastily built ones built with not so spare parts) wouldn't get anything less than about a 5 mV/m signal with a 120 foot antenna.

I had a Galena detector, and still do, but I never got it to work, even with a 100 mV/m nearby signal. The end of the Cat's Whisker broke off, and I had to straighten out some of the spring to restore a whisker. I suspect that you need to polish the oxide off the crystal to get a better connection. Somebody gave me a new Rocket Radio a few years ago, but I could barely get it to work with a 100 mV/m signal. I suspect somebody substituted a Silicon diode, not knowing that the signal would have to be 0.6-0.7 volts to work.

 

[Dave-N2DS]

Thanks for the nice comments. Those crystal sets and one tube radios are a hoot. Great dx can be heard
with them too. I built crystal sets in the early and mid sixties. I had fun then and at the turn of the century
I once again became interested in making crystal sets. I also operate a forum dedicated to small radio building.
So if you are interested in building a few radios, drop by theradioboard.com for a look.

73, Dave