[Premium-Rx] Looking for recommendations on high performance VLF receiver.

[Brooke Clarke]

Hi Tom:

I've had an interest in longwave for many decades, going back to when I ran a beacon "LAH" on 175 Khz in Los Altos 
Hills.  I found the Palomar Engineers VLF converter worked very well, See photo of CEI receiver rack control panel rear 
view:
http://www.prc68.com/I/CEI.shtml
It translated the band 10 to 500 Khz to be above 3.5 or 4.0 MHz on your HF receiver and so the dial reads the input 
frequency after dropping the MHz prefix.

The other antenna I used in that time frame was a long wire with a Miller 3 mH inductor with an adjustable core near the 
receiver. When the antenna capacitance was resonated the s/n improved a lot.

While a boat anchor the FRR-21 LF Receiver 145-600 kHz receiver brings in WWVB like a sledge hammer.
http://www.prc68.com/I/rack2.html

The AMRAD Active LF Whip would be great for NDBs, but not so good below 100 kHz because of conducted AC power line noise.
http://www.prc68.com/I/LF-Ant.shtml
http://www.prc68.com/I/Spec_0002.shtml

The McKay Dymec DA-100 active whip antenna works well for NDBs.
http://www.prc68.com/I/DR33.shtml#DA100

My ultimate receiver (although only for seeing signals since it has no way to "hear" them) is the HP 4395A.
When in Spectrum Analyzer mode it has a true 1 Hz Resolution Bandwidth (done using I&Q with a 12 MHz wide DSP IF).
http://www.prc68.com/I/4395A.shtml#SA
Here is a plot of 200 to 400 Khz:
http://www.prc68.com/I/Spec_0004.shtml

-- 
Have Fun,

Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html

-------- Original Message --------
> Hi Folks!
>
>
>    I've been having a blast pulling in VLF aircraft beacons in the 200-525 K/c range.
>
>    I am looking for recommendations for a premium receiver that will cover VLF. If it can cover say VLF to HF (maybe 10k/c - 30 Mc, that would be even better!)
>
>    Due to the nature and spacing of the signals, selectivity is an absolute must!  Signals can typically be 2 K/c apart from each other, creating all sorts of heterodyne issues.
>
>    My best receiver is the CEI-357 (R-1401): Sensitivity is good, selectivity is also quite good, but the noise blanker doesn't seem to work, and this a real performance killer (especially since we're getting into the noisy time of year!).
>
>    The CEI-357 has 6 K/c, 3 K/c, 1 K/c, and 100 Hz filters. For VLF work, the 3 and 1 K/c filters are what I primarily use. The 1 K/c filter gets used the most. Being able to use a .5 K/c filter would be a huge asset for pulling in the Canadian beacons that have the 400 Hz modulation.
>
>    Having the ability to go from AM to USB and LSB is also a huge plus: I bagged a beacon in the Caribbean (a 3900 mile path!) because I was able to switch to SSB and use a narrow filter.
>
>    Thanks in advance for your suggestions.
>
>
> -Tom
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