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OFF AIR but hope to be back by 1115z Saturday morning if I don't oversleep

Poor propagation from on going geomagnetic storm had a major impact on reports and QSO’s; Trans-Atlantic openings take a hit but a few openings persist; High noise in Oceania gives the impression of closed trans-Pacific paths; W5EST presents: ”MF/LF RX Antenna Coupling in the Midst of Local Noise”

– Posted in: 630 Meter Daily Reports, 630 Meters

The details for October 25, 2016 can be viewed here.

The UTC amateur registration database is here.

HERE are a few mode specific comments addressing where modes are located now and probably where they are best placed in the future

Curious about who is on the air making two-way QSO’s? Roger, VE7VV, is maintaining this list. If you complete QSO’s, be sure to let us know so he can add you to the active operator list.

Spot stations calling CQ on any mode here on DXSummit and help them find a QSO!

 

The bulk of North America was clear, however, the eastern seaboard into the Caribbean was party to a storm system with plenty of lightning.  Parts of New England were probably directly impacted by this system while others struggled with associated noise.  It was all quiet here in North Texas until twilight along the East coast when noise briefly spiked, presumably as the ionosphere tilted a bit and storm noise propagated West.  Heavy QRN was reported in Oceania by VK4YB while heavy weather in Hawaii cleared yesterday afternoon according to K9FD.

11-hour North American lightning summary

 

Geomagnetic conditions reached G1 storm levels during session with the possibility of G2 conditions over the next 24-hour according to Solarham. The Bz is pointing  to the South this morning but has generally remained at unity through the night.  Solar wind velocities peaked in excess of 650 km/s overnight. This morning velocities are averaging near 593 km/s.  DST values have decreased as expected but so far the decreases are not nearly as impressive as recent  events.

 

 

 

Propagation seemed pretty dead this morning in much the same way that it seemed dead last night.  Domestic openings have been hard to come by on CW and trans-Atlantic and Pacific reports are down significantly over the previous session.  So while the current G1 may not seem as impressive as recent coronal hole / solar wind events, it has definitely taken its toll.  Noise didn’t help the situation in a few key DX locations.

Reverse beacon network reports for the session follow:

 

PSKReporter’s presentation of digital modes for the previous 24-hours follows:

Courtesy PSKReporter

 

The following stations provided reports of their two-way QSO’s as well as any additional activity that might have occurred during this session (this is not necessarily a complete list – only what was reported!):

Mal, G3KEV, reported on an evening FT8 QSO with SV8CS on the RSGB-LF reflector.  No further details are available.

Eric, NO3M, observed a daytime (1604z) JT9 QSO between Wayne, N9EGT,  and Wayne, K9SLQ.  No further details are available.

Wayne, K9SLQ, reported a JT9 QSO with Al, K2BLA,  and Kermit, W9XA, this morning.

Ken, K5DNL, reported JT9 QSO’s with ZF1EJ.  He completed FT8 and JT9 QSO’s with W5EMC.  Overnight with WSPR, Ken provided reports for thirteen WSPR stations and he received reports from 72 unique stations including ZL2AFP, K9FD, ZF1EJ and nine Canadian stations.

Al, K2BLA, completed JT9 QSO’s with ZF1EJ and K9SLQ this morning.  A few WSPR transmissions yielded reports from 42 unique stations  including K9FD and KPH.  He provided reports for seven WSPR stations.  Al was also wondering where everyone was at this morning.  He’s right, it was pretty dead out there, but I suspect that poor propagation and the World Series last night is part of our answer.

Neil, W0YSE/7, was heard briefly at my station (KB5NJD) this morning in the noise but we couldn’t quite get it together for a QSO.  Neil submitted these comments about his QSO chase on CW and JT9 in addition to best WSPR DX overnight:

“Nice to have heard your CW, even if just barely, this morning. The band was kinda dead it seems. I did decode Ken, K5DNL on JT9 as he was working Eden, ZF1EJ. Ken was -24 dB here. I tried to give Ken a signal report on JT9 but I dont think he decoded it.  I got two spots on the VE7AB skimmer with my CW this morning.  Here are the best DX stations decoding my 1/2w ERP WSPR this session out of 25 unique spotters.”

Courtesy W0YSE

 

Roger, VK4YB, reported that “Heavy QRN prevented any chance of 2-way QSOs. On WSPR heard 4 (best K9FD) heard by 22 (best VE6JY).”  Roger received WSPR reports from JA1PKG/2, KL7L, KPH, KR6LA, N1VF, VE6JY, N6SKM and  W6SFH. He shared two-way WSPR reports with K9FD.

The band was very quiet during the evening but propagation was very poor.  A handful of weak signals were observed to the East but there was no real chance to raise an operator under those circumstances.  I initially blamed the fact that it was early and checked back 45 minutes later only to find that the situation was much the same as it was when I was originally tuning the band.  I QRT’ed for the night around 0230z.  This morning around 0910z I got started again.  The band was quiet this morning but no signals were observed except for a few weak and watery WSPR signals.  I called CQ on 474.5 kHz CW intermittently and tuned the band checking a number of azimuths.  I received a few reverse beacon reports from VE6 and VE7 but those were short-lived as was a nice report from AA4VV in the Carolinas.  Weird propagation like this is not surprising but the lack of stations heard this morning is.  If it was not for the fact that I checked a number of antennas I might think something was wrong.  I should also note that I had no sked this morning.  W0YSE reported me at RST 119/229 this morning as we were both receiving pings from VE7AB.  Neil was similarly just perceptible in the noise but what this really indicates is that there is hope for a future CW QSO.  The band will improve again.

Trans-Pacific report details, excluding KL7 and KH6, can be viewed here.

Hideo, JH3XCU, submitted this link detailing DX -> JA decode totals and DX -> JA S/N peaks for the session, as reported on the Japanese language 472 kHz website.

Trans-Atlantic WSPR report details can be viewed here.  The trans-Atlantic WSPR summary follows:

AA1A -> DL4RAJ, EA2HB, F1AFJ, F59706, G0IDE, G4ZFQ, PA0O, PA0RDT

Mike, WA3TTS, reported on the ON4KST chat that he decoded fourteen WSPR stations including thirteen decodes of K9FD (/KH6) as his best DX (-20 dB S/N at 0934z).  Mike also decoded ZF1EJ twenty times, best at -21 dB S/N at 0936z.

Regional and continental WSPR breakdowns follow:

North American 24-hour WSPR summary

 

European 24-hour WSPR summary

 

Asiatic Russia 24-hour WSPR summary

 

Japanese 24-hour WSPR summary

 

Oceania 24-hour WSPR summary

 

Eden, ZF1EJ, completed JT9 QSO’s with K5DNL and K2BLA.  Overnight he provided reports for seven WSPR stations including WH2XCR. He received reports from 37 unique stations.  He shared two-way reports with K9FD (/KH6).  Eden’s reports out West were significantly better than recent sessions in spite of geomagnetic storm conditions.

ZF1EJ session WSPR activity

 

Laurence, KL7L, experienced a tough session under current geomagnetic conditions in addition to poor terrestrial weather conditions resulting in his remaining receive-only for the entire session.  He provided reports for four WSPR stations including VK4YB and K9FD.  Laurence noted that this was KR6LA’s first time to be heard at his station.  Select DX report details can be viewed here.

KL7L session WSPR activity

 

Merv, K9FD, provided reports for fifteen WSPR stations including VK3HP and ZL1EE. He shared two-way reports with VK4YB, ZF1EJ and ZL2AFP. Merv received reports from thirty unique stations including JA1PKG/2, KL7L and VK2XGJ.  Select DX report details can be viewed here.

K9FD session WSPR activity

 

Jim, W5EST, presents “MF/LF RX Antenna Coupling in the Midst of Local Noise“:

“Many of us have small real estate, inescapable local noise, and low budgets. We have to face the ogres of local noise and imperfect antennas.  As you read this post, depending on your station, (Endnote 1*) for RX or TX/RX you might have a vertical, vertical with top hat, inverted-L, low-band HF dipole, bidirectional loop, or unidirectional loop .

Yesterday’s blog showed a noise-resistant coupling circuit for outdoors at the RX antenna.  Today’s illustration shows a scenario of coupling to an RX antenna system indoors to the RX where it can be more convenient.

An antenna cable run that has a grounded cable shield can form a capacitive voltage divider to ground. The purpose is to reduce local noise (dashed gray) by shunting it to ground. If there’s low stray capacitance to antenna and cable center conductor(s),  then a higher conductor-to-shield capacitance can complete a capacitive voltage divider that divides down local noise but preserves signal strength.

Additionally, the shield braid around the cable’s inner conductor(s) may shield the conductor(s) from local noise even if the shield braid is grounded at only one end or isn’t grounded at all.  Much depends on the particulars of noise source and antenna and cable locations at your QTH.  Use of two center conductors, or only one, in the cable will depend on your RX antenna type.

Coax that runs even a long way to shack from a 630m/2200m RX antenna will be electrically short, far less than ¼ wavelength. Outdoors, the challenge on these bands is to isolate the feed line from local noise while delivering plenty of signal and some inevitable band noise.

Feed line shunt reactance 1/2πfC can be problematic if it shunts desired signal from an antenna that has antenna impedance considerably higher than 50Ω.  At 630m, shunt reactance is simply 1 megΩ /3C, calculating in pF with total capacitance C of the feed line. 2500-3000pF arises in 100’ of feed line that has 25-30pF/ft, http://w4zt.com/coax.html .

That amount of total capacitance corresponds to a shunt reactance XC = -j100Ω. 

If you have an RX vertical, the feed line’s shunt capacitance C should be less than 1/10 the antenna capacitance as well. If not, use a loading coil and/or step-down RF transformer outdoors at an RX vertical antenna to push more RF current to the shack RX and lose less antenna current in the feed line’s shunt capacitance.

If overall outdoor RX antenna & ground system impedance as seen from the shack isn’t matched to the receiver, then turning up the RX RF gain may handle the problem.  If not, use a coupling circuit in the shack to better match the RX antenna to the RX.

Returning to the illustration, the shack has optional Matching to resonate the antenna when desired.  Matching compensates for capacitive or inductive reactance in the system and can increase signal level and band noise levels enough to overwhelm local noise.  (Endnote 2**)

If local noise is still significant, try noise isolation by inserting an RF Transformer T1.  Also, you can augment T1 with a simple noise canceller network S3, S4, P1, S5.  (Endnote 3***)

RF Transformer T1 can be a toroid with some appropriate turns ratio N1:N2. Connect T1 by switch S4 to selectively deliver signal and noise from its secondary winding to the RX directly or adjustably via a potentiometer P1. (P1 has resistance comparable to the RX input resistance.  Avoid a pot type that gets noisy when you adjust it, like some wirewound pots can be.)

Meanwhile, a center tap on the primary winding connects via SPST switch S3 to switch S4. Switch S4 reverses the roles of RX input and pot P1 wiper. Polarity-switching of T1 secondary by switch S5 completes the picture.

Set pot P1 to center position.  Randomly set switches S3, S4, S5 until you hear some noise reduction. Then adjust pot P1 for best SNR for a 630m signal.  The switches put local noise in approximate antiphase with itself. Pot P1 down-adjusts the relative amplitude of whichever is the stronger antiphase local noise to reduce the total local noise at the RX.  A more sophisticated phaser can work well but may be expensive to buy or time-consuming to build.

TU & GL on 630m!

*ENDNOTE 1: Scroll through the Chapter 2 pictures and titles of posts about different MF/LF operators’ RX antennas at:  http://njdtechnologies.net/your-630m-blog-book-a-compilation-of-the-work-and-analysis-of-jim-hollander-w5est/
** ENDNOTE 2: For an RX doublet, insert identical series inductors in two incoming leads of open wire line or twinlead.  For a vertical, vertical with top hat, or inverted-L, provide a loading coil outdoors to prevent coax shunt capacitance from unduly shunting desired signal. For a loop instead, apply a series resonating capacitor to increase signal level. If your circumstances permit, dispense with a cable shield entirely as per “600m antenna choices…” by Dave AA1A Oct. 22, 2017, at:  http://w7ekb.com/pipermail/600mrg_w7ekb.com/2017-October/015745.html
*** ENDNOTE 3: For discussion of another analog noise canceller and antenna system including small noise antenna and main antenna, see http://njdtechnologies.net/052816/   Today’s illustration omits the separate noise antenna by playing off the differential mode and common mode local noises in the system against each other.”

 

 


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