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Re: QRZ.com "distance" reports are different.
Julio Jimenez
This is a good discussion y'all. I've put some thought into the same subject after following in AA4XX's footsteps as the QRP ARCI awards manager.
toggle quoted messageShow quoted text
I have no clue what algorithm QRZ uses for distance calculations, but based solely on my research I've found that calculation based on the Haversine formula can have a 0.3% error (3m per km), especially if the distance is not parallel to a latitude line, given that Haversine assumes the earth is a sphere, from what I understood.
I also found the Vicenty formula, which takes into account the elliptical (or spheroidal?) shape of the earth, with a margin of error of 1mm per km, or whatever that percentage is...0.001%?
Aaaaanyways, I've been thinking about building an "official" calculator specifically for the 1000 miles per watt award based on some of the above research. What do y'all think?
Oh, and someone let me know if I was way off track with the math-talk above. VY 72 DE AK4VL Julio Jimenez
On Thursday, August 15, 2013, Todd F. Carney / K7TFC wrote:
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Re: QRZ.com "distance" reports are different.
John Lonigro
There is a simple trigonometric method for computing the great
circle distance between any two points on earth. If the earth were
a perfect sphere, the accuracy of the method would depend solely on
how well you know the coordinates of the two points. Because the
equatorial radius is slightly greater than the polar radius, the
method isn't exact, but using an "average" earth radius should be
accurate enough for most purposes. Measuring the distance on a map
probably won't give the correct answer, since you need to be
computing great circle distance, the shortest distance between two
points on a sphere.
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If anyone is interested, I'll see if I can dig up the equations. They aren't very difficult. Or you could do a Google search and come up with them yourself. 72's, John AA0VE
On 08/15/2013 02:39 PM, Todd F. Carney
/ K7TFC wrote:
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Re: Net Report
Ge Charles
toggle quoted messageShow quoted text
Yes I agree 40 m signals were much better on the second net. Tnx for your participation 72 Johnny
On Thursday, August 15, 2013, Charles Moizeau wrote:
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Re: QRZ.com "distance" reports are different.
Glen,
I just checked the QSOs in my QRZ log and all the distances agree. I would be interested in knowing what software (or function on the internet) QRZ uses to calculate these distances. I think I'll cast about the web looking for online distance calculators.
I do think it's cool that QRZ include this service, but for an award I'd be inclined to use a good-sized map and measure with an good-quality ruler. What's good sized? Well, at least 2x4 feet perhaps. The U.S. Geological Survey has excellent maps. So does the National Geographic Society. They have one of the United States that's 30x43" with a scale of 1:4,560,000. http://shop.nationalgeographic.com/coupon.jsp?code=NG20214&url=%2Fproduct%2F304%2F1293%2F173%2Ehtml. Like most maps, it has a scale reference in the legend box--miles/inch, or (easier to calculate) miles/mm.
I would like to hear what QRZ says.
73, Todd ------------------------------------------------------------------------------------ K7TFC / Medford, Oregon, USA / CN82ni / UTC-7 (PDT) ------------------------------------------------------------------------------------
On Thu, Aug 15, 2013 at 10:36 AM, Glen <glene77is@...> wrote:
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Re: Wed. night PSK checkins.
Virgil R. Hammond <n0tgr@...>
Phil: Digipan and Fldigi are two of the psk programs in use today, just google them in and download. that's about all that I can tell you Dick, N0TGR
From: Phil Anderson To: 4sqrp@...; Virgil R. Hammond Sent: Thursday, August 15, 2013 11:26 AM Subject: Re: [4sqrp] Wed. night PSK checkins. Virgil,
It has been perhaps 15 years since I've been on a digital mode other than CW. Perhaps it's time to check back in? In that regard: 1. What is the most popular program people are using that is compatible with system 7? 2. Where is the current best starter documentation? Uncle Phil, W0XI, 4sqrp #13. Only 7 or 8 months until the next OZARKCON!
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Re: Wed. night PSK checkins.
Jeremy Utley
On 8/15/2013 11:26 AM, Phil Anderson
wrote:
Probably the two best are DM780 or FLDIGI. I personally use FLDIGI all the time, because of it's cross-platform capability (I can use the same software in both Windows and Linux). Works great on Win7 - that's what my radio desktop runs usually. As far as documentation, there's plenty out there. Most of the difficulty is getting your interface set up right, and your volume levels correct. For my own purposes, I feel that using the Signalink USB is the best solution - this device essentially becomes a second sound card connected to your computer - this way you can configure the software to use the signalink, while your "normal" windows sounds still use the primary sound card on the computer. Plus, the pre-made cables make the setup a no-brainer. I myself use the Signalink, with their cables and a plug&play jumper board to fairly easily change between my FT-920 and FT-817. Just my 2 cents worth, Jeremy, N9PH Iola, KS
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Re: Wed. night PSK checkins.
Phil Anderson
Virgil,
It has been perhaps 15 years since I've been on a digital mode other than CW. Perhaps it's time to check back in? In that regard: 1. What is the most popular program people are using that is compatible with system 7? 2. Where is the current best starter documentation? Uncle Phil, W0XI, 4sqrp #13. Only 7 or 8 months until the next OZARKCON!
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Re: Net Report
w2sh@...
With an additional hour of darkness, 40m signals in NJ were stronger for the second net than the first. However, strong SSB QRM kept me from repeating my earlier QNI. On 80m nothing was heard here. 72, Charles, W2SH To: 4sqrp@... From: jomatlock@... Date: Thu, 15 Aug 2013 06:20:16 -0500 Subject: [4sqrp] Net Report
Gm:
Here are the net reports for last night, not too bad, lots of QRN! 7:30 40 M WB5CTS STEVE KV6Z BILL K2HT DICK W2SH CHARLES 80 M N9RLO JOHN 8:30 40 M KC0PMH WAYNE N9RLO JOHN N0YJ/P BERT AA5CO BRUCE KV6Z BILL Thanks to all that all that tried and all who made it in, it was fun! 72 JOHNNY AC0BQ Sent from my iPad
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New pictures added to my photo file
Wayne Dillon
I was messing with the W3EDP antenna last evening and have added some pictures of the set-up to my photo album on the 4SQRP yahoo group page.
The BalUn is a home-brew 4:1 on a T-200-2 core, as you can see it's connected right on the back of the LGD QRP Autotuner,
Enjoy, 72/3 es God Bless de Wayne - KC0PMH http://www.qsl.net/kc0pmh/ Under construction but please visit anyway.
QRP - EFFICIENCY AND SKILL, NOT POWER.
I'm British by birth but American by CHOICE! Jesus came to pay a debt He didn't owe because we owe a debt we cannot pay... The Lord bless you and keep you The Lord make His face shine upon you, and be gracious unto you The Lord lift up his contenance upon you and give you peace. God Bless from Wayne Dillon - KC0PMH Joshua 24:14-15 2 Cor 5:17 1 Jn 2:17 4 State QRP Group NCS - 40m & 160m 4SQRP #95
FPQRP #342 (Flying Pigs QRP Club) G-QRP-C #11504 NAQCC # 0759
QRP-ARCI #11505 SKCC #1155C SOC #848 30MDG#1176 NEQRP #693 GORC #192
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Re: QRZ.com "distance" reports are different.
Dale Putnam
You think it is bad figuring that out? Try running back and forth, until they do......  Have a great day, --... ...-- Dale - WC7S in Wy To: 4sqrp@... From: glene77is@... Date: Thu, 15 Aug 2013 10:36:56 +0000 Subject: [4sqrp] QRZ.com "distance" reports are different. Guys,
I wonder if anyone else has spotted this intermittent problem at QRZ.com ?
I have noticed a difference in
1) the QRZ.com reported "Distance"
vs.
2) the "Bio page" "Detail map" reported "Distance".
Sometimes it may be 40% milage off.
Most of the time it is the same.
/Start Quote/
#59401804 Log
Date: 2013-08-13 23:04:33 MST
QSO Start: 2013-08-13 23:03:00 UTC:
20LW. 941. Dale WC7S in WY
2nd time today.
QSB flutter 73.
Think Dale parks at 14.060.
QRZ "Bio" "Detail" (via Google) reports "Distance: 908.5 mi (1462.1 km)".
QRZ "log page" reports "Distance: 464.0 mi / 746 km"
Glen, updated.
/End Quote/
So, the question next is, running QRPp ,
if I apply for a "1000 miles per watt certificate",
which figures do I use ?
Have submitted a Service Requist to QRZ.com.
This example is just the latest,
not the big one, at 1600 miles on a Watt of power.
This problem is not 100%, just often enough to be spotted.
Anybody else spotted this problem ?
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Re: Tonight's nets
Paul Smith
Hello,again, I tossed my call out a couple times hoping for a response on 3564,3565 and 3566...... I will keep riding along awaiting cooler wx of the fall de Paul N0NBD
On Aug 14, 2013, at 10:02 PM, Johnny <jomatlock@...> wrote:
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Net Report
Gm:
Here are the net reports for last night, not too bad, lots of QRN! 7:30 40 M WB5CTS STEVE KV6Z BILL K2HT DICK W2SH CHARLES 80 M N9RLO JOHN 8:30 40 M KC0PMH WAYNE N9RLO JOHN N0YJ/P BERT AA5CO BRUCE KV6Z BILL Thanks to all that all that tried and all who made it in, it was fun! 72 JOHNNY AC0BQ Sent from my iPad
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Re: LT SPICE circuit draw and simulate program DOWNLOAD
Glen <glene77is@...>
Nick, WA5BDU,
toggle quoted messageShow quoted text
Have purchased the HiPerMite and the NeScaf filter kits. Have designed/breadboarded a Butterworth BandPass quad stage audio filter. Has been interesting to research this field, in order to design/build my 'own' active filter. Plan to add my active filter into the HW-8 circuit, and put the other two in an off-board cabinet. Has been very interesting to go through all this process. Have Multi-Sym running, and my old LTspice on the shelf. Have not been great at either. Wish there were Linux versions of these. On the HW8, I have experimentally discovered that the "N"arrow filter is 600Hz. Have calculated from the schematic that this is so. Will be raising it to 750Hz, so that the "N"arrow matchs the Transmit Offset of 750Hz. The method is to alter the R(2) which pulls two caps down to ground, by lowering the value. On the Butterworth , I simply lower the R(2) value by -40% . Results will be that Q will drop -25% aprox, and the Freq(center) will raise +25% aprox. This works predictably on my five stage bread-board Active Filter Project. Matches my calculations close enough, monitoring with the O'scope. Regarding the HiPerMite Freq(center). Any suggestions for raising the HiPerMite Freq(center) from 700Hz to 750Hz, to match the HW-8 Transmit Offset of 750Hz ? It seems simple enough to move the HiPerMite #4 HiPass stage down with a padding cap. But that would make the mis-match worser. I want to move the three LoPass stages up 50Hz. Maybe I should just "breadboard" the kit, and tinker ? I am familiar with BandPass Butterworth calculations, but the HiPerMite is a Lo-Lo-Lo-Hi design, and I wanted some suggestions before I started re-calculating everything. Have designed a Butterworth BandPass Active Filter, of five stages, low Q, at 750 Hz. On the Butterworth , I simply lower the R(2) value to ground by -40% aprox . That pulls both caps down. Results are that Q drops -25% aprox, and the Freq(center) raises +25% aprox. Acceptable variations in my circuit. Everything is calculated prior to changes, and the O'scope is used for measurements. In the beginning of this study, I used a calculator for everything, however K7MEM had some modeling suggestions. So, now, in practice, I calculate everything, using the K7MEM website and MikeYancey website modeling pages. So, I wonder if there is a particular perspective to use in changing the HiPerMite ? Glen, KK4LPG, bio on QRZ.com
--- In 4sqrp@..., Nick-WA5BDU wrote:
> > Yes, LTSpice is one of the very best free technical programs out there. > True, there's a learning curve if you want to get into complex stuff, > imported models, etc., but you can start simple. > > BTW, I uploaded a model of the HI-PER-MITE filter recently. It's in the > "files" area of the 4SQRP Yahoo group page. > > 73- > > Nick, WA5BDU > > On 5/1/2013 11:14 AM, Phil Anderson wrote: > > > > Hi Guys, > > > > snip > > > > One of the programs I've used at least once a week is still available > > free as a download from Linear Technology; it is called LTspice and > > allows you to draw circuit schematics, save and/or print them, and > > simulate the circuit, showing calculations, signal traces, and frequency > > responses (and freq content)! > > > > Documentation is reasonable but it takes a bit of time to learn. You can > > download LTspice from www.linear.com and then go to tools to find the > > LTspice IV download. Download is very quick. It installed AOK on Windows > > 7 and I had previously used it on Windows Vista home edition too. > > > > 72, Uncle Phil, W0XI > > > > > > > > > > > > > > > > >
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QRZ.com "distance" reports are different.
Glen <glene77is@...>
Guys, I wonder if anyone else has spotted this intermittent problem at QRZ.com ? I have noticed a difference in 1) the QRZ.com reported "Distance" vs. 2) the "Bio page" "Detail map" reported "Distance". Sometimes it may be 40% milage off. Most of the time it is the same. /Start Quote/ #59401804 Log Date: 2013-08-13 23:04:33 MST QSO Start: 2013-08-13 23:03:00 UTC: 20LW. 941. Dale WC7S in WY 2nd time today. QSB flutter 73. Think Dale parks at 14.060. QRZ "Bio" "Detail" (via Google) reports "Distance: 908.5 mi (1462.1 km)". QRZ "log page" reports "Distance: 464.0 mi / 746 km" Glen, updated. /End Quote/ So, the question next is, running QRPp , if I apply for a "1000 miles per watt certificate", which figures do I use ? Have submitted a Service Requist to QRZ.com. This example is just the latest, not the big one, at 1600 miles on a Watt of power. This problem is not 100%, just often enough to be spotted. Anybody else spotted this problem ?
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Re: Tonight's nets
Tnx Paul for trying I swear I heard you on 80 meters???? I guess not? 72 Johnny ac0bq Sent from my iPad
On Aug 14, 2013, at 8:51 PM, Paul Smith <psmith61@...> wrote:
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Wed. night PSK checkins.
Virgil R. Hammond <n0tgr@...>
Wed. night PSK checkins: KA0KRN David, Ottumwa, IA AC0WZ Dan, Fulton, MO K0SSZ Jason, Emporia, KS K2HT Dick, Wellsville, MO Good net, no qrm, tnx fer checkins, N0TGR Dick, Augusta, KS NCS
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Tonight's nets
Paul Smith
Johnny,
I listened up and down and never heard anything but noise. Maybe another day. 80 was incredibly noisy! de Paul N0NBD Sent from my iPad
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Net tonite
Ge group:
Terry is out of town so I'm going to pick up NCS on 80 meters at 8:00 pm central time. I have some really strong local QRM so qsy up a little and look for me please around 3566? Either Wayne or my self will be NCS at 7:30 and 8:30, I am not sure which, but have a listen and someone will be calling Cq, who knows might be both of us?? Any way please join in tonight for the 4 SQRP Wednesday night net. 72 GL JOHNNY AC0BQ Sent from my iPad
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Luncheon Meeting Saturday
David Bixler <qrp@...>
Hello folks:
This is your reminder message that the August luncheon "chat and chow" get-together is this upcoming Saturday, the 17th at the Country Cupboard restaurant in downtown Seneca. Lunch is at 11:00 in the meeting room. Directions are posted on the 4SQRP web site. <http://www.4sqrp.com/CountryCupboard.html> 73, Dave W0CH
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RMRc net rpt and ??
Dale Putnam
8-13-13 WC7S (NCS) -7- WC7S AA7CU K2HT W5HNS KK4BNC KK4LPG K0DTJ (2045)
8-13-13 WC7S (NCS) -3- WC7S KK4LPG AA7CU (second session) (2245z) We had a total of 10 stations, checking into the two nets. In the expansion to two nets for the check of propagation, and avoiding the T-storms, the additional comment that maybe 40 would be better. It seems that 40 would be interesting to address, although, it likely wouldn't be long enough to gather in both coasts, at our net times. I'm looking for input, so if you have a "druther" bring it forth, or state your preference, Survey time:
Understanding that not all the net checkins read this reflector, consideration will be given to those that don't. Thanks for your help, Have a great day, --... ...-- Dale - WC7S in Wy
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