I discharge it thru' the xyl
first.
Rog.
----- Original Message -----
Sent: Thursday, August 02, 2007 7:54 AM
Subject: Re: LF: Re: Re: newbie help
Good point Ha-Jo. When using my antenna impedance analyser, I
always leave a
50 ohm load in parallel with the antenna, using a BNC
T-piece. Only when the
antenna is connected do I remove the 50 ohm
terminator, that way hopefully
any static on the antenna is discharged
through it.
73
Tom G3OLB
----- Original Message -----
From:
<[email protected]>
To:
<[email protected]>
Sent:
Wednesday, August 01, 2007 11:20 PM
Subject: Re: LF: Re: Re: newbie
help
> Dear all,
>
> I have heard of a case that a
german LF amateur had ruined his
> capacitance meter because of a static
loading on the aerial!
>
> Therefore I have always preferred to
measure aerial capacitance by
> checking the detuning effect of the aerial
to a tuned circuit. The coil
> of this circuit will always ground the
aerial for dc.
>
> HW?
>
> 73 Ha-Jo,
DJ1ZB
>
>
> "John GM4SLV" <[email protected]>
schrieb:
>>
>> Rog,
>>
>> That's an
interesting idea - I've never thought of trying a digital Cap
>> meter.
I must try it on the new antenna - and compare it to my homebrew
>> RF
bridge, calculations and - more telling - to the valuse of L I
>>
eventually need to resonate it.
>>
>>
>> John
GM4SLV
>>
>>
>> On Wed, 1 Aug 2007, GW3UEP
wrote:
>>
>> > Re ant cap: you can use a DMM [Rapid 328] to
gnd - I use 1000pF across
>> > its terminals to decouple RF for a
stable reading. Simply subtract its
>> > value. 73, Rog.
>>
>
>> > ----- Original Message -----
>> > From: James
Moritz
>> > To: [email protected]
>>
> Sent: Wednesday, August 01, 2007 12:05 PM
>> > Subject: LF: Re:
newbie help
>> >
>> >
>> > Dear
Paul,
>> >
>> > In a nutshell:
>>
>
>> > - You can tune up more or less any bit of wire for
reasonable results
>> > on 500kHz. For best results, make it as high
up as possible, and
>> > secondarily as long as possible. An HF long
wire, or dipole with
>> > feeders strapped would be
fine.
>> >
>> > -Work out the capacitance of the wire
(see formulas on ON7YD's
>> > antennas pages). and calculate the
inductance for resonance around
>> > 502.5kHz. For most HF-sized
wire antennas, this will be of the order
>> > of 100s of uH. The
resulting coil is
>>
>>
>>
>
>
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