Re: Non-ultralight owner question(s)...


Kevin Schanilec
 

Hi Mark:

I'll take a stab. I think location is a huge part of it. Out on the west coast here, going to the beach on the Pacific makes Asian and Down Under signals quite doable, while the signals drop off if you trudge just a mile or two inland. If the signals are coming in well, you don't even need a very good receiver: for instance, one morning at the beach I had 774-Australia coming in on a barefoot Tecsun/Kaito R-911, which has only decent sensitivity and selectivity.

Allen and Diane's results in Newfoundland I think are testimonies to the advantages of their location, which is away from the RF clutter of the eastern seaboard, and even the more modest RF of St. John's, allowing the infamously broad-filtered Sony M37 to really shine as a DX receiver, and the SRF-39 is obviously cleaning up as well. Plus, they are about 2500 miles from the center of Europe, almost all by water path, while I am a lot farther away from Asia and Down Under.

For those of us with more mundane DX locations (such as Milwaukee?), the signals are attenuated, and the added selectivity of the newer DSP sets is much more important IMHO. The 1 khz spec on the DSP sets is per sideband (not total), and to my ear is actually not as tight as a Murata 2.3 khz filter; I would guess closer to 2.8 khz? With that actual filter width, AM signals are not too muffled. In fact, with a good sharply-tuned antenna (a Q multiplier helps), one can de-tune 2 khz and really get good treble response (and get away from interference). The skirts are pretty darn good on the DSP sets.

Timing is also critical. For trans-Pacific signals, there is generally an enhancement of signals around our local sunrise, while it is still quite dark in Asia and Down Under. There are nights when as soon as it starts to get dark over there (say, around midnight my time), the signals start popping up, but within an hour of my local sunrise is generally the best time to give it a go. For trans-Atlantics, as soon as it starts to get dark where you're at is likely the time to start checking.

Hope this helps - Kevin S
Bainbridge Island, WA

--- In ultralightdx@..., "airchecklover" <mdh@...> wrote:

Hey all and Allen in Newfoundland in particular; I've been reading this group for a while and am amazed at the DX reports, esp. for MW. As subject line states, I don't own an Ultralight but I do have several good non-DSP radios incl. an Eton E1, a Sony 2010 and Drake R4C. I've built several multi-turn open loops, own the Palstar amplified ferrite system and also a CCrane Twin-Ferrite - and I've been hamming on and off for 45 years. So I'm not new to radio. But i'm new to reading and believing you can hear MW stations from around the world while sitting on the eastern edge of the N. American continent. How si this possible? Is it the QTH allowing this? A 1 khz DSP-defined bandwidth? The advantage of a "super-Q" homebrew long ferrite antenna? In my experience, a 2.3 khz "SSB filter" is almost too narrow for intelligible Amplitude Modulation (AM) recovery while a 1 khz "CW filter" is too narrow. Yet I'm seeing reports of stations at 909 khz or 1089 khz or 1341 khz. How is this possible? Is there something about the DSP filter - with perhaps super-steep skirts that is allowing for this? But still, a 1 khz RF passband is not going to allow more than 1 khz audio, which is too narrow to discern anything more than vowels (ie, no consonant differentiation possible). Or have I been a student of theory too long and simply need to 'try it'?? Anyone care to take a swing at enlightenment? :)

Thanks in advance, Mark

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