QRP Club

QRP Station => Builder's Corner => Topic started by: vu2nan on December 26, 2015, 13:14:52 UTC

Title: UHF Crystal Radio
Post by: vu2nan on December 26, 2015, 13:14:52 UTC
May be viewed at

http://nandustips.blogspot.in/2015/12/uhf-crystal-radio.html (http://nandustips.blogspot.in/2015/12/uhf-crystal-radio.html)

73,

Nandu.
Title: Re: UHF Crystal Radio
Post by: GM0LVI on December 26, 2015, 19:17:36 UTC
Very ingenious Nandu!!!
Title: Re: UHF Crystal Radio
Post by: vu2nan on December 27, 2015, 02:20:39 UTC
Thanks, OM Dave!

73,

Nandu.
Title: Re: UHF Crystal Radio
Post by: vu2nan on January 06, 2016, 14:20:20 UTC
There's been an update.

http://nandustips.blogspot.in/2015/12/uhf-crystal-radio.html (http://nandustips.blogspot.in/2015/12/uhf-crystal-radio.html)

73,

Nandu.
Title: Re: UHF Crystal Radio
Post by: vu2nan on January 20, 2016, 06:28:40 UTC
Another update.

A folded dipole version, mounted on a terminal block.

It obviates the need for a coil / additional diode and works quite well too.

Regards,

Nandu.
Title: Re: UHF Crystal Radio
Post by: vu2nan on January 23, 2016, 18:31:13 UTC
Yet another!

The terminal block arrangement made it convenient to replace the folded dipole with a full wave loop.

Likewise with an AWX antenna.

Results were as good as with the folded dipole.

73,

Nandu.
Title: Re: UHF Crystal Radio
Post by: vu2nan on January 30, 2016, 17:55:38 UTC
The latest update!

A second Yagi Beam was then rigged up, with another diode providing the return path for the audio, instead of the coil.

The signal strength was not as good. During trials, a chance shorting of the second diode gave a considerable increase in signal strength.

The diode and capacitor were hence discarded. Performance of this single-diode UHF crystal radio is quite good.

73,

Nandu.