Hi Ken,
Am 03.01.2011 10:07, schrieb Ken:
Hi Stefan.
I have just completed your VLF
Active Antenna except for the 4:1 transformer
Fine! You can try to run the antenna without the transformer. Just add
it later and see if there is an improvement! Compare it to the antenna
you used befor and see if there is a significant difference. Find a
suitable location and reduce the mains hum. This is essential for
proper working!
, considering all my previous
correspondence regarding sound card microphone input impedances being
anywhere between 4k ohms and 10k ohms, are you using this as a step
- up or step - down transformer,
I am using it as a step down transformer.
and which sound card input are you
using mic or line input?
I only have one input on all the 6 PCs i currently know/use. This is a
microphone input i assume.
I will be using Winrad 1.32, and
was hoping to complete in order to look for Chris G3XIZ today as his
QTH is 20km from my self.
Wishing you good luck with you
sub9kHz work in 2011.
TNX! Good luck and all the best for 2011!!
73, Stefan
73s.
Ken
M0KHW
----- Original Message -----
Sent:
Wednesday, December 29, 2010 6:16 PM
Subject:
Re: LF: DK7FC's VLF Active Antenna
Hi Ken,
I have not tested other JFETs so far. Is it just because of the SMD
housing? I don't use a SMD PCB but a "free air" soldering. So if this
is the problem, just solder the FETs legs directly on the next part,
e.g. solder the drain directly on the 390 Ohm resistor. Attached you
find a picture that shows how my current used VLF grabber antenna looks
inside. Don't be shocked ;-)
If you anyway want an alternative, the J310 or the (2SK170)
should be possible. There are some parameters like the noise and the
gain and the input capacitance which are affecting the performance but
this is all not so critical on VLF.
73, Stefan/DK7FC
Am 29.12.2010 17:58, schrieb Ken:
Stefan.
Could you please recommend an
equivalent to to BF862 which is not Surface Mount for use in this
circuit.
73s
Ken
M0KHW
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