[Lowfer] VLF Alphas

[Douglas D. Williams]

Most VLF converters that I know of use cheap "computer" crystal oscillators
that drift too much for QRSS work. The only one I know that is adequate for
QRSS work is the AMRAD clone that Todd Roberts custom builds with a 3.0 MHz
OCXO. Don't know if he still builds them or not.

D.

On Wed, Nov 19, 2014 at 10:25 AM, Jay Hainline <ka9cfd at mtcnow.net> wrote:

> I also have the LF Engineering L-111 VLF converter box but I cant get it
> to tune accurately and it drifts like crazy. I can't recommend it. Maybe
> others have had better luck.
>
> 73 Jay
>
> Jay Hainline KA9CFD
> Colchester, IL EN40om
>
> -----Original Message----- From: Douglas D. Williams
> Sent: Wednesday, November 19, 2014 15:09
>
> To: Discussion of the Lowfer (US, European, &amp,UK) and MedFer bands
> Subject: Re: [Lowfer] VLF Alphas
>
> The only thing that I use is a 50 kHz low pass filter between the output of
> the DC coupler and the Mic input on my PC, but that isn't really necessary.
> Of course, I wouldn't leave it connected if there were thunderstorms
> anywhere near. An audio isolation transformer might work also.
>
> The e-probe I am currently using is the Clifton Labs model, and if I
> connect it as described above and unmute the mic input in the mixer
> setting, I can actually hear tweaks and spherics from my computer speakers,
> as if I were listening to a whistler receiver, except the low frequency
> cutoff is higher, at around 5 kHz or so.
>
> D.
>
> On Wed, Nov 19, 2014 at 9:52 AM, Jay Hainline <ka9cfd at mtcnow.net> wrote:
>
>  I should try that sometime. Any protection needed between the coax that
>> would go to your receiver to your mic soundcard input? I am using the LF
>> Engineering L-400B antenna.
>>
>>
>> Jay Hainline KA9CFD
>> Colchester, IL EN40om
>>
>> -----Original Message----- From: Douglas D. Williams
>> Sent: Wednesday, November 19, 2014 14:41
>> To: Discussion of the Lowfer (US, European, &amp,UK) and MedFer bands
>> Subject: Re: [Lowfer] VLF Alphas
>>
>>
>> Forgot to mention the maximum frequency you will be able to see will be
>> half the sampling rate of your sound card. So if you have a 48 kHz sound
>> card, you will be able to see up to 24 kHz on Spectrum Lab's display.
>>
>> D.
>>
>> On Wed, Nov 19, 2014 at 9:38 AM, Douglas D. Williams <kb4oer at gmail.com>
>> wrote:
>>
>>  Tom, a cheap VLF receiver can be your computer's sound card. If you have
>>
>>> an e-probe that is sensitive at VLF, you can often connect the receiver
>>> output of your DC power coupler directly to the mic or line in on your PC
>>> and view the output using Spectrum Lab software (free). Spectrum Lab has
>>> some included settings what have common VLF stations already marked on
>>> the
>>> spectrum display.
>>>
>>> -Doug
>>>
>>> On Wed, Nov 19, 2014 at 9:32 AM, Garry Hess <k3siw at sbcglobal.net> wrote:
>>>
>>>  Tom, the VLF captures were made with a rooftop eprobe and sdr-iq
>>>
>>>> receiver.
>>>>
>>>> Re: lowfer EAR: J.B., it's coming in well here too but MLS isn't even
>>>> detectable despite being a bit closer.
>>>> --
>>>> 73, Garry, K3SIW, EN52ta, Elgin, IL
>>>>
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