[Lowfer] SDR RX Suggestions

[J D]

 >>> Was just looking for something better to snag KE, TIM and 22A.

The receiving setup is only half the equation. Remember Billy Preston's 
surprisingly apt lyric, "Nothing from nothing leaves nothing." NOTHING 
will pull a nearly non-existent signal out of the background, no matter 
how ultradigital the radio may be. Popular priced SDRs were not invented 
because analog radios were too deaf, but simply because it's easier and 
cheaper to implement and revise certain useful features in software. And 
to be frank, while I obviously can't generalize about all SDRs, the 
waterfall displays I've seen with some of them are not nearly as well 
matched to the characteristics of QRSS signals as Argo is.

The stations you receive all the time with the present setup are not 
exactly superpowered either, and are certainly nothing to sneeze at. KE 
may be improving gradually, but still has a ways to go before it's 
radiating signals comparable to those old-timers...whereas, so far as I 
know, 22A has never been reported publicly by anyone since shortly after 
it first went on the air, and it's presently unclear if TIM has made it 
out of Illinois yet.

 >>> For listening I use a LF Engineering Active antenna and a 1/4 wave 
insulated 160 meter vertical. Believe it or not the 160 meter vertical 
works the best which I wouldn't have expected.

As long as it's not sited in a noisy environment (and especially if the 
transmission line is decoupled from ground at one or both ends, per Low 
Noise Vertical principles), there should be no surprise when a big 
antenna outperforms a small one at LF. It inherently intercepts more 
energy from the EM wave. And even though impedance transformation is 
still desirable, especially at lower frequencies, the greater terminal 
voltage means the transformation can be passive instead of active, 
greatly reducing the odds of intermodulation products, clipping, 
internal or power supply generated noise, etc.

My own dream receiving setup would include a tall vertical such as yours 
on my farm, along with a loop and a phasing arrangement for when 
directionality is needed, working into an analog receiver front end with 
a low phase noise L.O. and robust mixer, a modest selection of good 
roofing filters, then at least a 32-bit DAC driving a floating-point 
I.F. DSP. (I have no need for full band spectrum display, wideband RF 
recording, built-in Morse decoders, dual or triple receivers, etc. Those 
who do can indeed get all that digitally, but there are always 
performance tradeoffs to take into account.) Your own setup sounds like 
it is already pretty close to my wish list in terms of performance.