Re: LF: DK7FC's VLF Active Antenna

[Daniele Tincani <danieletincani@yahoo.com>]

Hello Ken,

I bought the BF862's at RS Italy. The sell them in 10x strips. May be you could try and see if RS UK have the same policy.

Best regards

Daniele

 

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From: Ken <ken.h.wright@btinternet.com>
To: rsgb_lf_group@blacksheep.org
Sent: Thu, December 30, 2010 11:24:00 AM
Subject: Re: LF: DK7FC's VLF Active Antenna

Hi Stefan and all others.

Thank you for your most useful replies, the reasons I asked this question are as follows, firstly I was hoping to construct one this weekend possibly from components in my stock, a quick search on Google for UK suppliers came up with Farnell and RS, phoned Farnell and was informed yes I could purchase but there is a minimum  order policy of £20 which equates to about 50  BF862s, I assume that RS is the same, I also looked on Ebay non were found. If anyone knows of a UK supplier where I could purchase say 10 ff I would be grateful.

 

73s

Ken

M0KHW

----- Original Message -----

From: Stefan Schäfer

To: rsgb_lf_group@blacksheep.org

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