NJDTechnologies

Radio: it's not just a hobby, it's a way of life

Current Operating Frequency and Mode

CQ 474.5 kHz CW and alternately tuning 472 kHz - 475 kHz for signals.

High activity and good band conditions result in a fun night; Night one of the MF QSO Party in Europe; Trans-Atlantic activity in Southeastern US

– Posted in: 630 Meter Daily Reports, 630 Meters

A lot of operators are commenting about the large number of stations that were transmitting during this session in combination with really quite good band conditions.  It was a fun night with a significant number of big reports and the geomagnetic field appears to have behaved itself for the most part.

planetary-k-index 032016

 

Kyoto DST 032016

 

Australia 032016

 

Doug, K4LY / WH2XZO, received trans-Atlantic reports for his signal during the session and offers these additional comments and statistics:

WH2XZO 032016

 

John, WA3ETD / WG2XKA, experienced an open path to the west coast and Pacific Northwest, which has recently been somewhat anaemic:

WG2XKA 032016

 

WG2XKA map 032016

WG2XKA session WSPR activity

 

David, G0MRF, received quite a number of reports, including trans-Atlantic reports from WG2XJM and WD2XSH/17.  David provided these additional comments:

G0MRF 032016

Night one of the MF QSO Party in Europe has so far resulted in the following comments from Rik, OR7T, and Markus, DF6NM:

Thank you Vinny, for the nice idea and the invitation to the party!

For me, it sure was a lot of fun, and resulted in a number of JT9 QSO’s with OR7T, DG0RG, SV8CS, SV3DVO, DL6II, DD2UJ, IW4DXW, LA8AV, F6CNI, and DK7FC. Most signals were promptly decodable (except for my report from DL6II which was lost due to temporary drift). A copy of my receive log is at http://df6nm.bplaced.net/MF/jt9_party_160319.txt .
But operating workflow was not easy for me. I don’t have an MF SSB transmitter available here, just an AD8950 DDS-board with a three-wire serial interface. So I decided to modify my homemade WSPR software, such that it reads a message from the command line, converts it to tone numbers by calling Joe’s JT9CODE.EXE, and plays it at the beginning of the next minute. Lacking the “late-start feature”, the text had to be typed and ready on time, and it was practically impossible to immediately reply to a decoded message. This was further exacerbated by the lack of automatic message generation (“three click QSO”), and some uncertainties of shorthand versus free-text length. I’m sorry if I have been taxing the patience of my QSO partners!
Regarding the receive software, if I had two free wishes this is what I would suggest:
– Show decodes as spectrogram labels:
Coming from visual QRSS, I like to “see” who I work. With many stations in the spectrogram, it can be challenging to keep an oversight on who is who, and on which frequency. It would be nice to see the decoded messages as labels near or on the traces in a wide horizontal spectrogram. replying by clicking on colour-highlighted labels would seem more intuitive than clicking in the separate text decode window.
– Show partial decodes:
When the signal is not too weak, the software could already attempt to decode a message before it has been completely received. Decoding zero padded audio (e.g. two extra times after 30 and 40 seconds) would give the operator significantly more time to think up an appropriate (non-automatic) response.
Best 73,
Markus (DF6NM)”

 

OR7T 032016

87 MF WSPR stations were reported on the WSPRnet activity page at 0400z.  Regional and continental WSPR breakdowns follow:

NA 032016

North American 24-hour WSPR activity

 

EU 032016

Europe 24-hour WSPR activity

 

JA 032016

Japanese 24-hour WSPR activity

 

VK 032016

Australian 24-hour WSPR activity

 

There were no reports on the trans-African path, however ZS1JEN and UA0SNV were present during the session.

The trans-Atlantic path opened to the south eastern US once again resulting in WH2XZO being decoded in Germany.  G0MRF was also reported in the north eastern US.

WH2XZO DL4RAJ 032016

WH2XZO, as reported by DL4RAJ

 

WH2XZO DL4RAJ2 032016

WH2XZO, as reported by DL4RAJ/2

 

G0MRF WD2XSH17 032016

G0MRF, as reported by WD2XSH/17

 

G0MRF WG2XJM 032016

G0MRF, as reported by WG2XJM

 

In the Caribbean, Eden, ZF1EJ, operated two receivers during this session and provided a number of reports in North America:

ZF1EJ 032016

ZF1EJ 24-hour WSPR activity

 

ZF1EJ1 032016

ZF1EJ/1 24-hour WSPR activity

 

In Alaska, Laurence, KL7L / WE2XPQ, continues as a receive-only station, reporting stations in the western portions of North American and Hawaii.

WE2XPQ 032016

WE2XPQ 24-hour WSPR activity

 

WH2XCR WE2XPQ 032016a

WH2XCR WE2XPQ 032016b

WH2XCR, as reported by WE2XPQ

 

In Hawaii, Merv, K9FD/KH6 / WH2XCR, had a good session with the mainland of North America, reporting stations in the eastern US.  Merv also reported VK3ELV and was decoded by John, VK2XGJ.

WH2XCR 032016

WH2XCR 24-hour WSPR activity

 

WH2XCR VK2XGJ 032016

WH2XCR, as reported by VK2XGJ

 

 

In Australia, Phil, VK3ELV, received reports from Hawaii and Japan.

VK3ELV WH2XCR 032016

VK3ELV, as reported by WH2XCR

 

VK3ELV JH3XCU 032016

VK3ELV, as reported by JH3XCU

 

VK3ELV JH1INM 032016

VK3ELV, as reported by JH1INM

 

VK3ELV EJTSWL 032016

VK3ELV, as reported by EJTSWL

 

Additional comments, statistics, anecdotes and information:

Joseph, NU6O / WI2XBV, reports that band conditions were above average but that wasn’t enough to yield reports in the East.

Toby, VE7CNF, reports that John, VE7BDQ, was operating both WSPR and JT9 during the session.  John notes that he would probably QRT by 0900z.  Toby went on to report that he was reported by twelve stations and reported 28 stations including KB0EMB, KG7GVF, WE2XGR, and WG2XPJ.

Phil, VE3CIQ, reports that he decoded ten unique stations while being decoded by 21 unique stations, with my station here in Texas being the most distant.

Doug, K4LY / WH2XZO, reports that he decoded thirteen stations and was decoded by 42 unique stations including DL4RAJ, WH2XCR, and VA7JX.  He add that this was a top-five best session.

Ron, NI7J / WH2XND, reports that he decoded thirteen stations and was decoded by 42 unique stations.

Ken, SWL/EN61, in Indiana reports high activity and sixteen unique stations decoded.

Ken, K5DNL / WG2XXM, reports that he decoded fifteen unique stations, three of which were in VE, and was decoded by 44 unique stations, six of which were VE.  He also reports that he decoded Merv’s one-watt ERP ten times, with the best at -22 dB S/N.

Larry, W7IUV / WH2XGP, reports a much better session compared to the previous week, decoding thirteen unique stations and being decoded by 42 unique stations in the last 24-hours.

Jim, W5EST, bring us a continuation of yesterday’s discussion on current readings entitled, “EXTRAPOLATING ANTENNA RF CURRENT READINGS, PART 2”:

“Recall the example from yesterday’s blog—Get a desired level, say 1.50A, of RF current using an RF ammeter at the base of your 630m or 2200m top-hatted transmit vertical.  In the example, you measured I1 =0.63A antenna base current with TPO 11 watts.

You then upped the TPO to four times as much power– 44 watts. If the RF ammeter were calibrated right, it should show 1.26A– double the earlier 0.63A.  You could use yesterday’s method and calculate  P =44 x (1.50/1.26)2 watts.

Today the harder, less-satisfactorily calibrated scenario is our topic.  At 44 watts TPO, suppose you see the ammeter reading I2 = 1.15A instead.  Also, you check what the meter reads with the TX off.  Let’s say it reads I0 = 0.02A that way.  Of course, it should read precisely zero.  While it’s possible that in yesterday’s example the ammeter had some consistent error in it too, today’s example gives considerable reason to doubt the accuracy of readings this ammeter gives.

The hypothetical goal in this example is 1.50A actual antenna base current, not a 1.50A reading on the less than perfectly calibrated RF ammeter.  So how much TPO should you set in the shack to get that 1.50A?  Plainly, TPO should come out close to the 62 watts figured with the perfect meter yesterday. But how can we determine the correct TPO from an imperfect RF ammeter?

One good solution is get a better ammeter or have a friend calibrate it in a lab.  If possible, great, do that.

Otherwise one can take a couple of approaches.  First approach (hard) would move the ammeter to the ATU input, get a 1:1 SWR match to the ATU input and then calibrate with respect to 50Ω according to the formula  I = sqrt(TPO/50Ω).  You would laboriously graph ATU input current values as shown on the meter versus calculated current values according to I = sqrt(TPO/50Ω).  Then you would reconnect the ammeter to the base of the antenna and use yesterday’s procedure P =P2 x (Idesired /I2)2 watts.  The calibration graph would help you measure I2 properly.

You might try a simpler method: Get an accurate RF current for just one reading on the meter. You’d can move the ammeter to ATU input do one meter reading and calculate just one value of I = sqrt(TPO/50Ω). Then reconnect the meter to the antenna base itself, take readings as described yesterday (Part I) and do some math.  The math is the $64 question for another post.

If even that simpler method is too inconvenient, then simply assume the mid-scale meter values are the least inaccurate ones and do a math correction for the rest.  Ditto more about that, another post.  Thanks for getting this far, and GL!”

 

Additions, corrections, clarifications, etc?  Send me a message on the Contact page or directly to KB5NJD <at> gmail dot (com)!