Date
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ULDXIndex and MWDXerDB V22.03
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Paul Blundell
Fair point and clearly I have misread the feeling of how this should work. Paul |
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Jorge Garzón <iberiaDX@...>
When I introduced back in april 2021 the ULDX Index I wanted to get a math value (an Index) easy to be recognized internationally, obtained in a quantitative way, as always numbers show. Under these premises, experienced DXers face the challenge: distance and power of a given station. To achieve a difficult DX we experiment, design antennae or choose a vantage spot to hear weak signals. How difficult is DXing a station with an UL receiver? That's the value shown by the Index: the higher the score, the most difficult challenge to face! The way to calculate is easy: D (distance, km) / W (power, watts). Thee is also a world recognized code to show a signal quality: the SIO and SINPO codes. Scored from 1 to 5 gives an idea of the listening conditions: S: Signal strenght, I: Interference (QRM), N: Noise (QRN), P: Fading, and O: Overall quality. Signal strenght can be accurate with a signal meter, but a few ULR have implemented them, and those with give erratic readings. Interference can vary in very short distances or depends on electronic devices around. Noise increases or decreased according to regional conditios or meteo conditions. Fading is related to surroundings, combination of waves and propagation itself. Overall signal is a combination of the former ones and includes the subjective sensation of listening comfortability. Quality of the signal values have then more to see with QTH conditions, meteo, or qualitative aspects. Use them as ULDX index modifiers would distort a quantitative math index. That's why they are not included as a part of the index score itself and that's why SIO/SINPO was implemented by DXers many years ago. Of course DXers can achieve the challenge as they prefer, but in my opinion the way to calculate the index should be kept in a quantitative method as this is a global way to compare by numbers the challenge to get that wanted DX with an ULR. Saludos Jorge |
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On Thu, Mar 10, 2022 at 07:24 PM, James Rohrer wrote:
I think it's time for a reality check here. Long range DX is very dependent on seasonal changes, especially transoceanic DX on medium wave. For example, here in the USA I can routinely receive transoceanic DX from Asia in the fall, and from Australia in the spring and summer. What Paul is doing is receiving the same eastern Australian stations over and over, which can be routinely received by anyone with a radio at night in his location. Everyone is free to choose the style of DXing they prefer, of course, but if you are interested in long range and/ or transoceanic DX on medium wave, you will need to learn the seasonal propagation changes in order to have much chance of success. Gary DeBock (in Puyallup, WA, USA) |
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Paul Blundell
I would not think so, I have found that the time of day is a bigger factor. Paul On Fri, Mar 11, 2022 at 2:24 PM James Rohrer <Jim.rohrer1955@...> wrote:
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Paul |
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James Rohrer
Do you expect the ULI scores to be lower during the spring and summer? On Thu, Mar 10, 2022 at 9:20 PM Paul Blundell <tanger32au@...> wrote:
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Paul Blundell
The latest version is now online: https://ultralightradiodxing.blogspot.com/2022/02/software-mwdxerdb.html |
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Paul Blundell
I have now made a change to how this is handled. Instead of adding them to a single file, I have created a file for each frequency and station, this will be updated each time I log the station and add the ULDXIndex. Paul |
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Paul Blundell
Yeah, that is one way of doing it. The original way didn't include the signal level, it was something I have added. On Wed, Mar 9, 2022 at 2:34 PM James Rohrer <Jim.rohrer1955@...> wrote: See if I did this correctly. WWL New Orleans 870 AM came in tonight. 1635 km / 50000=.0327. Signal strength five so multiply and get .1635 as my index value. --
Paul |
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James Rohrer
See if I did this correctly. WWL New Orleans 870 AM came in tonight. 1635 km / 50000=.0327. Signal strength five so multiply and get .1635 as my index value.
Yesterday evening KCJJ in Iowa City 1630 AM came in 5 by 5. Distance is 330 km. Night watts are only 1000. Index value is 1.65. This is ten times better than the index i got from hearing the Clear Channel station down at the end of the Big Muddy. This suggests to me that instead of searching for strong signals I should make a list of 1000 watt broadcasters in my area and go hunting for them on my radio. |
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Issac Quincey
Is that what you have coded this with? Would you think about my offer to review the code for security holes and bugs?
Sent with ProtonMail Secure Email.
------- Original Message ------- On Wednesday, March 9th, 2022 at 8:17 AM, Paul Blundell <tanger32au@...> wrote:
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Paul Blundell
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Paul Blundell
Yes, that is the formula I use. I did also look at using two numbers but this got a bit confusing so I just give each signal a single index score. On Wed, 9 Mar 2022, 12:46 am James Rohrer, <Jim.rohrer1955@...> wrote:
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FenDrifter
BODMAS Paul?
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James Rohrer
Paul, Do you compute like this? Dividing before multiplying. ULDXIndexValue = (DistanceKM / PowerW) * SignalLevel Regarding signal level, I guess '5by5' could be guideline. If the signal is both strong and clear, then give it a 5. |
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Paul Blundell
I don't use the signal meter, it is more a mix of signal level, audio quality and how "clean" the signal is. On Tue, Mar 8, 2022 at 12:45 PM James Rohrer <Jim.rohrer1955@...> wrote: Now I understand the importance of taking Station power into account and not just distance. tonight I heard I in 1630 Iowa City. Only 200 miles away but not heard before. 10,000 watts. My radio does not display signal power so I cannot compute the index . I need another radio. --
Paul |
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James Rohrer
Now I understand the importance of taking Station power into account and not just distance. tonight I heard I in 1630 Iowa City. Only 200 miles away but not heard before. 10,000 watts. My radio does not display signal power so I cannot compute the index . I need another radio.
Focusing just on AM sensitivity, not SW, which UL is best value? Needs to display signal strength. |
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Paul Blundell
Yes, here in Australia we have the ACMA database which gives the "straight line" distance between my location and the station Ihear, this is the distance I use. Paul On Tue, Mar 8, 2022 at 3:08 AM James Rohrer <Jim.rohrer1955@...> wrote: My inclination is to use miles to the farthest station heard in a session. Google miles gives shortest road distance. This like bragging about the biggest fish you caught. --
Paul |
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Paul Blundell
Hi Bill, I rate all the signals out of 5 and then use the below to work out the index value. 1 = 1.1 2 = 1.4 3 = 1.9 4 = 2.4 5 = 3 ULDXIndexValue = DistanceKM / PowerW * SignalLevel Paul On Tue, Mar 8, 2022 at 3:04 AM mediumwavedx <desertbilly@...> wrote: Hi Paul, --
Paul |
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Paul Blundell
Those are just callsigns of some stations to use as examples. Paul On Tue, 8 Mar 2022, 12:45 am James Rohrer, <Jim.rohrer1955@...> wrote:
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FenDrifter
Yea, whatever you do, don’t use the evil Google. I use this site to obtain ‘as the crow flies’ distances:
https://www.doogal.co.uk/MeasureDistances.php Drifter |
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