开云体育

On Mar 12, 2023, at 8:34 AM, Larry Macionski via groups.io <am_fm_radio@...> wrote:

?Next you'll be climbing my tower. very nicely done. Old School, but I can't remember the advantage of winding that in that fashion..

I think the first guys that wound them got the idea from their mothers who wound wool yarn on the coil form to make hot pads. in the pioneering days of radio, wood stoves and iron skillets were the cook ware of the times.. and counters and kitchen tables were not Formica or granite like they are now.

Are you going to make a broadcast band radio receiver or something else... maybe a metal detector... err bomb detector as they called it in WWII..

prior to inventing a bomb detector they would release a herd of goats into the field...

So that means that metal/bomb detectors are PETA approved... Funny when you think about it.

Larry W8LM

On Mar 13, 2023, at 10:45 AM, Larry Macionski via groups.io <am_fm_radio@...> wrote:

?Excellent- sounds like my 1st radio a crystal set. It required high impedance headphones- or a crystal earphone.. just like the crystals hams used to use to determine frequencies of their transmitter. It used the electro-mechanical properties of quartz. if you apply a slight voltage to a quartz crystal, it vibrates. if you keep changing the electrical stimulation it converts the electrical signal to audio vibrations. But with DC it starts vibrating at a specific frequency.

My 1st radio was a design found in the boy scout Radio merit badge.. I built it in a cigar box. - you could get empty cigar boxes at the drug store if you begged long enough or took the trash to the dumpster for them. A cigar box was a cherished posession. It could contain, baseball cards, toy soldiers, marbles or jax. Sometimes even a few coins and hard candy.

My 1 tube radio was actually a dual triode..6SN7 and one of the 1st stations I heard was CKLW in Canada.. Little did I know at age 12. CKLW 800Khz. was a clear channel 100,000 watt radio with a 5/8 antenna along side of the Detroit river actually about 5 air miles away in Canada.... CKLW back then ran twice the power of any US station and had twice the antenna. It covered 43 states at night and better than 1/2 of Canada to the Arctic circle.
The other station I would listen to was WCAR... It broadcasted the Detroit Tigers Baseball. WCAR was limited to 1000 watts at night and had a 12 antenna array pointed north to provide Michiganders who would escape Detroit in the summer and head to cooler northern Michigan. You could hear WCAR 500 miles north but not 20 miles south at night. The station engineer of WCAR gave me my novice test back in 1966...Blame him...

Larry W8LM