QRP Club

QRP Station => Builder's Corner => Topic started by: vu2nan on September 01, 2015, 14:54:51 UTC

Title: Crystal Radio Output Transformer
Post by: vu2nan on September 01, 2015, 14:54:51 UTC
Here's the link.

http://nandustips.blogspot.in/2015/09/crystal-radio-output-transformer.html (http://nandustips.blogspot.in/2015/09/crystal-radio-output-transformer.html)

73,

Nandu.
Title: Re: Crystal Radio Output Transformer
Post by: ve3lyx on September 04, 2015, 04:12:33 UTC
Over the last two days I have been playing with a shortwave crystal set I built years ago as a shack tool. I can use it as a monitor or use it to check if a newly built transmitter is actually on freq or is pumping in through an if or image (the crystal set only hears where it is tuned). Yesterday in a moment of thought i wondered what would happen if I took the diode and phones off the tank circuit, wound a multi turn coil on the end of the coil form and reconnected them there. Sort of a built in audio transformer. It works and I can yesterday and today here the station on 3215 (last night was stronger then tonight) and can just hear the CHU time signal. The station on 3215 is 750 miles away as the crow flies so I am calling this experiment  success. Your post audio transformer, crystal set hit the subject dead on so I stuck it here. Hope that is OK.
don
Title: Re: Crystal Radio Output Transformer
Post by: vu2nan on September 05, 2015, 05:46:58 UTC
Hi OM Don,

Crystal radios are great fun because of the endless variants resulting from shack conditions.

Many thanks.

73,

Nandu.
Title: Re: Crystal Radio Output Transformer
Post by: ve3lyx on September 06, 2015, 01:13:10 UTC
For sure. I see you spend a lot of time at it. Passive radio is to me very fascinating. When one thinks that when the Titanic sent its message it was heard in Tobermorry Ontario probably on a passive detector and no amplifier as we know it. I have here an old book on radio telegraph from back then. Every once and a while I read a bit in it. I had mine on again tonight. Listening to a Florida station just above 40m band. I never knew it could still be done. I may be addicted! Would be fun to do a QSO with a crystal set rx.
Keep posting your stuff. I am reading.
don VE3LYX
Title: Re: Crystal Radio Output Transformer
Post by: vu2nan on September 07, 2015, 04:24:45 UTC
Sure, OM Don.

Many thanks.

73,

Nandu.