Re: LF: Sub 9kHz antenna tests.

[Gary - G4WGT <g4wgt@tiscali.co.uk>]

Hi Eddie,

Yes, you will need a pre-amp, don' forget that the E-Probe has a pre-amp. I advise you to build the M0BMU VLF pre-amp with 7 to 10 kHz band-pass filter, circuit attached.

73, Gary - G4WGT.

On 5 March 2011 14:22, qrss@talktalk.net <qrss@talktalk.net> wrote:

Hi Gary

I am testing a very similar loop to your 1.1m square, mine is 800mm sq. and uses Litz wire. Results at the same hight as my E-Probe are disappointing as yet.

I have no pre amp on it, and am wondering whether it would be advantageous as when tuned to 8.9kHz the noise level rises by 10dB. I suppose I shall end up building an amp to try but I would welcome any thoughts from the group.

73 Eddie G3ZJO

On 05/03/2011 12:35, Gary - G4WGT wrote:

Hi All,

Whilst monitoring 9090kHz & 8970kHz using SpecLab at 423uHz, I am testing 3 different VLF Rx antenna types :-

1 - An 84mH shielded ferrite loopstick (10mm x 200mm), 1 metre above ground
2 - A modified PA0RDT Mini-Whip, 8 metres above ground
3 - A 1.1 metre square loop with 46 turns of 1mm insulated wire, 1 metre above ground

Both of the loops using M0BMU VLF pre-amp.

I have had No. 1 connected since 2000utc last night until 1030utc this morning, no signals detected on the SpecLab display. I have connected No. 2 at 1030utc & notice a fall in noise level of about 10dB & a greater visibility of the Alpha signals. Later today I will connect the large loop & report my findings.

73,

Gary - G4WGT - IO83qo.

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