Re: LF: Ferrite antennas

[Roger Lapthorn <rogerlapthorn@gmail.com>]

Mike

If the ferrite rod was the drain load what was on the gate?

73s
Roger G3XBM

Via my iPod Touch 4g 2.4GHz handheld. 

On 12 Sep 2011, at 13:36, "Mike Dennison" <mike.dennison@ntlworld.com> wrote:

> I have been following the discussion on ferrite receiving antennas - 
> due to work pressures I am a few weeks behind in reading the mail.
> 
> The use of this type of antenna for LF amateur radio is not new. I 
> used it successfully as a portable antenna on the old 73kHz band 
> several years ago. 
> 
> I used the existing winding (LItz) an ordinary long-wave broadcast 
> radio antenna. The rod was about 150mm long. The coil, tuned with a 
> large fixed C and a variable C, formed the drain load of a 2N3819, 
> with the output taken from the source. The selectivity was very high 
> indeed (essential to reduce the huge commercial signal on the 73kHz 
> band) and sensitivity was adequate to overcome the noise level of my 
> very sensitive Datong LF converter.
> 
> The interesting thing was that Peter, G3LDO, tried to replicate this 
> and had poorer results, perhaps indicating that not all long wave 
> radios had ferrite that worked at 73kHz.
> 
> Mike, G3XDV
> ==========
>