Calculating gain in dB.

Yes but Nigel I still would like to experiment.

rjenkinsgb, thanks for the link.

Lightium said:

Yes but Nigel I still would like to experiment.

Click to expand...

Feel free, buy why try and invent the wheel?.

I am not familiar with the sensitivity of RTL dongles at any frequency, let alone below 500kHz.
However, i suggest that you look at this old post where I showed an amplifier/antenna for 500kHz (ish)


The amplifier does work quite well.

As built it tunes from just below 500kHz to about 1600kHz, it has a modest gain (I have not measured it), but importantly it has a reasonably narrow bandwidth so that it is not overloading the following receiver.

As others have said, you will not get a significant improvement by dunking the amplifier in a bucket of ice or liquid helium!

JimB

JimB, thank you for your time. Oh, that schematic looks perfect for working with. I'll have lots of fun.