Hi Stefan,
Indeed - but for an existing design, the through-hole parts are favoured
(just flip the JFET around if the pinout is Gate-Source-Drain instead of
Drain-Source-Gate as for J310 vs BF245). In the meantime, one of my last
J310's has been salvaged from a 70 cm RX preamp, and installed in VLF6.
Hope it will pick up something below 1 kHz from you one fine day ;-)
73,
Wolf .
On 23.01.2018 13:45, DK7FC wrote:
http://www.iup.uni-heidelberg.de/schaefer_vlf/VLF/J310.jpg
They have been quite cheap ( ~ 0.6 EUR) just a few (< 5) years ago.
Now they are not available any more. Looks like it is good to invest
in such parts before they are not availble any more.
On the other side, the SMD parts can be used as well, just a bit more
effort. Like the BF862,
http://www.iup.uni-heidelberg.de/schaefer_vlf/VLF/BF862.jpg
73, Stefan
Am 22.01.2018 18:08, schrieb Wolfgang Büscher:
Greetings all,
Storm "Friederike" has taken her toll - the enclosure of my VLF6 had
a small crack, so water slowly crept in, which slowly killed the high
impedance input.
It's in for repair now. Hope the FETs survived - I'm slowly running
out of stock of these ancient J310 devices.
Hope to be back soon.
Cheers,
Wolf DL4YHF .
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