Martian Special Radio

[DavePEI]

It gives one pause to consider that it is coming up on a hundred years since individual experimenters started making up such sets.  When I was a kid, 100 years predated the telephone.

Yes, well I built my last one before this one 56 years ago. My, how time flies when you are having fun! Then I graduated to tube radios, the solid state, but nothing beats the simplicity and fun of these! Would have made it much easier, though, had I simply used a 1N34A instead of the cat's whisker. Hard to find these days. Come to think of it, they weren't easy to find in 1959 either. I couldn't find one back then. Time had marched on even then.

Dave

[19and41]

There is a well earned sense of accomplishment from making such a creation perform as expected.  I was 2 or 3 when you made that last one.  My first crystal set was one of those little rocket shaped units with the sliding ferrite core tuner.  I cheated, like any self respecting 6 year old would do. 

[DavePEI]

There is a well earned sense of accomplishment from making such a creation perform as expected.  I was 2 or 3 when you made that last one.  My first crystal set was one of those little rocket shaped units with the sliding ferrite core tuner.  I cheated, like any self respecting 6 year old would do. 

My first one which I made when I was seven, was quite simple, but all home made. I wound its coil on a thick paper tube - I think it was from a roll of waxed paper, and since I couldn't find a cat's whisker then, I used a semiconductor diode (if I remember correctly, an OA90 or 95, but it might have been a 1N34). Seems to me, I found the plans back then in an old "Boy's Own Annual". For a young boy, having a radio then, especially one he built himself was magical!

Unbeknownst to my parents, I put the headphones on at night, and left them on my head while I slept. I still remember the voices of Wolfman Jack (XERF 1570 khz) and Cousin Brucie (WABC 770 khz) over the so called clear channel stations, These could be heard over most of North America. There was a San Francisco station which I used to listen to at times when it can through without too much fading, but I forget its call. Before I could hear them, I had to wait each night until the local station CFJR (1450 khz) reduced their night-time power as required by their license.

And even though many might consider me too young, my favorite tunes are those of the later 50s and early 60s, probably due to them becoming imprinted subliminally on my mind while I slept!

I think most people would prefer the songs from their teens onward!

Dave

[TelePlay]

And quite appropriately for this forum, I remember not being able to string an antenna at that time, and I discovered connecting the antenna terminal to the finger stop on a phone dial worked quite nicely :-)

Well, I had to check that out.

Hooked up my meter to the finger stop of a '64 500 and either red or green (both gave the same reading) at the wall end of the line cord. Found a 0.1 nanofarad capacitance which must be the result of the "large" base plate being so close to everything else attached to but isolated from it. Next test is to attach a radio later today.

[TelePlay]

Hooked up my meter to the finger stop of a '64 500 and either red or green (both gave the same reading) at the wall end of the line cord. Found a 0.1 nanofarad capacitance which must be the result of the "large" base plate being so close to everything else attached to but isolated from it. Next test is to attach a radio later today.

Okay, next step.

Checked the resistance between the finger stop and the line cord, tested as an open circuit.

Hooked up the finger stop to my Martian Radio after finding a sweet spot using a 81A buzzer, the old  linesman's tracer. Was able to hear a station but just barely and on only one side of my headset. Since my hearing is suspect, I had my wife listen and I think she heard about what I was hearing and only on one side of the headphones.

Removing the clip from the finger stop resulting is total silence in the headphones. Only thing I did not like about the finger stop antennae was it produced a 60 cycle buzz.

So, will try again tonight to see if the reception is better. I could hear conversation which faded in and out but could not make out what was being said to identity the station.

So, my Martian radio is still working after all these years.

[DavePEI]

Hi John:

One of the sad things that has happened over the years, is many AM radio stations have migrated over to the FM band. Here, on PEI, we have no AM radio stations left -- the stations still exist, but now they are broadcasting on the FM band. Your best bet will be night-time, when the AM Dx will roll in. Have fun! Still won't be as much fun as it was in the 50s and 60s!

Dave

[19and41]

On the little germanium set I had the instructions advised to use the finger stop (among other things) as it's ground.  the taps in the house were too big to clip onto.  We had an AM station about 8 miles away and getting it was like turning on a light switch.

[TelePlay]

Tried again at 7:15 pm and picked up one station loud and clear. Got my portable AM radio to find out what I picked up. It was 1640 AM, a station in Milwaukee some 30-40 miles from where I live.

That's encouragement enough to put up a real long wire antenna and run a real ground wire.

Then I happened to find this ended auction, wow!

http://www.ebay.ie/itm/141556848030

Also, discovered the buzz was from improper crystal tuning (learning curve thing). Done correctly, no 60 cycle hum in the headphones.

[DavePEI]

Tried again at 7:15 pm and picked up one station loud and clear. Got my portable AM radio to find out what I picked up. It was 1640 AM, a station in Milwaukee some 30-40 miles from where I live.

That's encouragement enough to put up a real long wire antenna and run a real ground wire.

Glad you had the enjoyment of hearing a station with it. What I used for an antenna when I was young, was a long wire antenna strung from end to end in the attic of our house. Worked great. I grounded to a nearby copper water pipe. One has to watch these days that they have a true ground on a pipe, since much modern plumbing is plastic...

Dave

[19and41]

It's nice to see good results with those units.  Wonder how a blue blade or foxhole detector would perform compared to a Galena detector.

[DavePEI]

Well, years ago, I tired out a Wilkinson's Blue blade and safety pin, and it worked pretty well.

Dave

[19and41]

I guess that could be the lead free version of the crystal set.   

[TelePlay]

Those detector kits are readily available.

http://www.ebay.com/itm/Gillette-Blue-Blade-Crystal-Radio-Detector-Kit-/250495237073

The common term for them are foxhole radio since these items were found to work by men in the trenches and foxholes of WW-I. One can wonder who thought that up, to use those common items to pick up emerging radio signals.

[TelePlay]

Sent an email to the radio station asking for their tower location and power.

The tower is about 10 miles from me and they put out 1,000 watts at night. Guess that's about right for a crystal radio. Anyone ever get a station father away?

[19and41]

WOWO was about 55 miles away and 50kw.  I could get them at night.