locked Re: VLF Reception

D R
 

Hi prog - would you recommend the 4.7nF cap in place of the short across R3 which I've had in place since early January, or would it not make much difference?  The short works very well with my loops, but every little extra is welcome.

Regards,
Dave


On Friday, 11 May 2018, 11:47:25 GMT+1, prog <info@...> wrote:


On Fri, May 11, 2018 at 03:35 am, Alan G4ZFQ wrote:
The only reception I get is on my discone, so I'd suggest anyone tries any "stupid" antenna they have.
Not uncommon. Good HF antennas are in general poor in the VLF band. In the other hand, the NF of the HF+ is so low that a small whip would work just fine and without modding anything. Just make sure you are not contaminating your antenna with your own noise. Leif posted a series of videos about this topic, so I invite everybody to check his YouTube channel: https://www.youtube.com/channel/UClmNy6VRE1YqOeBHwb3o0Yg/videos

FYI. The newer HF+ batches have a 4.7 nF coupling cap in the HF path and the RF front-end was programmed accordingly. This helps getting a better impedance matching with some antennas like the active loops/mini whips. Other antennas should work the same.

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