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Current Operating Frequency and Mode

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DK7FC -> WE2XGR/3, WE2XGR, WG2XJM -> G3XKR; VO1NA CW audible at PA0RDT; Enhancements and early propagation in the Pacific; Is forecast geomagnetic storm a ‘paper tiger’ or just late?; WH2XXP -> CE0Y??? What’s this?; Big night for WE2XPQ

– Posted in: 630 Meter Daily Reports, 630 Meters

Trans-Atlantic openings joined trans-Pacific openings once again in a mostly quiet session where the geomagnetic field remained relatively calm in spite of forecast storm conditions.  Domestic reports were significantly enhanced as well, with many stations reporting positive or single digit negative S/N numbers, even on longer paths.  Many stations noted very strong transcontinental reports very early in the evening as darkness enveloped the Pacific Northwest.  Neil, W0YSE/7 / WG2XSV, reported decodes of his 1W ERP signal as far east as WE2XGR/3 and it was before 0400z.

early-tx-wg2xsv-102416

In the West, similar early reports were noted by WA3TTS:

wh2xxp-wh2xcr-102416

WH2XXP early report at WH2XCR

 

Merv has been reporting many of us early, well before sunset in KH6 and has been making it a point to be QRV extra early so he does not miss these bizarre openings.

There were only a few terrestrial storms in continental North America although a number of stations continue to report high winds, limiting their ability to operate long term.

lightning-102416

10-hour North American lightning summary

 

Geomagnetic activity was quiet to unsettled during this session.  The Bz is pointing to the South although solar wind has returned to low levels below 400 km/s.  DST values are showing signs of  being effected by recent solar wind but the storm levels that were forecast to have started by now have not yet manifest.  Reports from KL7L indicate auroral activity but he indicates that it is currently not very strong.  It remains to be seen whether this event was weaker than expected or is just late in arriving.  In the past, the latter has been the most common answer.

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kyoto-dst-102416

 

australia-dst-102416

 

There was more activity in Europe than has been seen recently.  Stefan, DK7FC, reported that IW4DXW was activity on HELL mode during the evening:

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IW4DXW HELL at DK7FC

 

Joe, VO1NA, reported that he was active on CW on 477.7 kHz until 1000z on Monday and Roelof, PA0RDT, reported “excellent aural copy” at 2220z on the RSGB “blacksheep” reflector.

Domenico, IS7SLZ, reported:

“I’m cq’ing on MF using QRA64 mode included in wsjtx 1.7.0 version.  Qrg is dial 472.2kHz +1200 Hz. Tx even.  See on-line screenshots herehttp://www.qsl.net/iz7slz/OPDS/grabber.jpg Reports are welcome.  73, Domenico iz7slz”

Later in the evening, Tobias, DG3LV ,posted the following report:

“Hi Dom !
sorri, I did see your signal in the waterfall, but no decodes.
Later on heard G6AVK in mode QRA64 at JO53GV:

2033 -20  0.7 1201 :* CQ G6AVK JO01   ~England
2035 -14  0.7 1201 :* CQ G6AVK JO01   ~England
2109 -14  0.6 1200 :* CQ G6AVK JO01   ~England

73 de dg3lv Tobias”

Domenico added later,

“Tobias,  thank you for watching my signal yesterday evening. Colin G6AVK has reported also my signal there with thanks. There was also an attempted qso with Riccardo IW4DXW.  Since there are many wspr’s stations on-air in these days that, most probably,  can operate also QRA64 or JT9,   i will repeat ,  this night, the test with QRA64 signal starting at 20.00 UT.  QRG is dial 474.2 kHz + 1200 Hz .   Hope to have a 2-way qso using QRA64 on MF (maybe the first-one ?).  In case of difficulties i can revert in JT9.  QRA64 is designed for EME QSO, so i don’t think it is directly useable here on MF/LF. Its bandwidth is big compared to tipical modes in use on MF/LF but… it’s worth trying.  WSJT-X Version in use here is v1.7.0-rc1 r7107. Hope to have wspr-15 in the future again available on WSJT-X for the use on LF.  All the best.  Domenico, iz7slz”

Its good to see all of this varied activity.

Trans-Atlantic WSPR reports were observed on the signals of  DK7FC and WG2XJM during this session:

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WG2XJM, as reported by G3XKR

 

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DK7FC, as reported by WE2XGR

 

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DK7FC, as reported by WE2XGR/3

 

John, W1TAG / WE2XGR/3 added the following additional statistics for stations on longer-haul paths from this session:

“Heard WH2XCR (9x), DK7FC(9x), WI2XBQ(1x), WG2XSV(1x), VE7SL(16x).”

John, WA3ETD, also got in on the transcontinental action with reports from WH2XCR:

“After being QRT for four days due to driving rain and 50 mph gusts, the session  here was very strong, XKA heard 14 stations and was heard by 40.  Both way spots were managed with several in the very active southwest and PNW.  WH2XCR also reported this station.  RX noise levels were surprisingly high due to the receding storms in the northeast.  I was forced to shut down around 0530 due to high SWR caused by sagging top loading as the support trees continue to struggle under gusty winds.”

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WG2XKA session WSPR activity

 

Doug, K4LY / WH2XZO,  installed a second “KAZ” style receive antenna facing to the west and early results suggest that its very good.  Doug presents his details and statistics below and reports that he will provide additional thoughts about the Super Kaz receive antenna in the future:

“Heard 17 unique stations, most for season (maybe ever) and heard by 28 unique stations, average for a good night.

The combination of good and fairly quiet conditions plus a new antenna resulted in my best ever reception to the west with all time best SNRs of VE7SL (-14), probably the other VE7s who were heard for only the first or second time this season – VE7BDQ, VE7CNF, and VA7MM.  Also WH2XXP (-8), WH2XXP (+4), WG2XXM (+14), and probably others were all time high SNRs.  Also 2nd ever decode of WI2XBQ who reports running much less power this time.

It’s difficult to quantify how much better the Super KAZ antenna is than  my other receive antennas, but last night I decoded WH2XCR 14 times.
In the last two weeks he decoded me most nights, 73 times in all, but not a single decode from him last night, and I decoded him an all time most of 14 times.
Hawaii and the VE7’s-“
wh2xzo-102416
Phil, VK3ELV, was reported by three JA’s including JF1LKS_3, who is reporting Phil for the first time this season based on my records:
vk3elv-7l1rll4-102616

VK3ELV, as reported by 7L1RLL4

 

vk3elv-jf1lks_3-102616

VK3ELV, as reported by JF1LKS_3

 

vk3elv-jh3xcu-102616

VK3ELV, as reported by JH3XCU

 

John, VK2XGJ, indicates that a few reports were not uploaded to the database and so he provided screen captures of his WSPR console in lieu of uploaded data:

vk2xgj-102416

VK2XGJ WSPR console

 

Roger, VK4YB, reported, “Widespread opening, low noise, mostly mid-twenties s/n. Unlikely to reach cw levels. Code 6”  His statistics and details follow:

“Rx 11*wg2xxm (-17) 24*wh2xnd (-15) 31*wh2xxp (-11) 3*ve7bdq (-24) 11*wi2xbq (-25) 10*we2xpq (-22) 31*wh2xcr (-12) 17*wh2xgp (-21)

Tx 20*ve6jy (-19) 6*w7iuv (-22) 1*ve7cnf (-29) 6*ve7bdq (-19) 1*wi2xjq (-30) 17*ve7sl (-22) 9*w1ck (-25) 31*we2xpq (-19) 43*wh2xcr (-7) 3*jh1inm (-23) 1*jh3xcu (-26) 4*ja3tvf (-24) 7*zl2bcg (-5)

vk4yb-ja3tvf-102416

VK4YB, as reported by JA3TVF

 

vk4yb-jh1inm-102416

VK4YB, as reported by JH1INM

 

vk4yb-jh3xcu-102416

VK4YB, as reported by JH3XCU

 

vk4yb-ve6jy-102416

VK4YB, as reported by VE6JY

 

vk4yb-ve7cnf-102416

VK4YB, as reported by VE7CNF

 

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VK4YB, as reported by VE7SL

 

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VK4YB, as reported by W1CK

 

vk4yb-zl2bcg-102416

VK4YB, as reported by ZL2BCG

 

There was a rather remarkable reception made recently that I am now authorized to report.  Referencing comments made in the September 8, 2016 report, Alejandro, LU8YD, solicited MF stations that were interested in possibly be reported from CE0Y, Easter Island while there on a DXpedition.  The reports were not real-time, instead the 472-479 kHz passband was recorded and decoded after return to Argentina.  Alejandro reports the following operating conditions:

“Signal level peak: –115 dBm in Perseus SDR receiver. Antenna: 200 meter long Beverage beam North.  Hard geomagnetic storm  K= 5 in that day.”

Would it have been possible on a day of quiet geomagnetic conditions?  Who knows.   As it turns out, one of our own was reported on this trip, Ward, K7PO / WH2XXP.  Alejandro sent screen captures an audio clearing showing the WSPR signal and CW ID in addition to a raw audio file where Ward’s CW ID can be heard.  Kudo’s to Ward and Alejandro on this remarkable achievement and perhaps this means good things are truly possible for MF DXCC someday:

 

wh2xxp-ce0y-102416

WH2XXP WSPR and CW ID at CE0Y (Courtesy K7PO and LU8TD)

 

Ward’s session report details of seven VK’s and ZL2BCG:

wh2xxp-102416

WH2XXP session WSPR activity

 

wh2xxp-ejtswl-102416

WH2XXP, as reported by EJTSWL

 

wh2xxp-vk2ddi-102416

WH2XXP, as reported by VK2DDI

 

wh2xxp-vk2eik-102416

WH2XXP, as reported by VK2EIK

 

wh2xxp-vk2xgj-102416

WH2XXP, as reported by VK2XGJ

 

wh2xxp-vk3elv-102416

WH2XXP, as reported by VK3ELV

 

wh2xxp-vk4yb-102416

WH2XXP, as reported by VK4YB

 

wh2xxp-vk5abn-102416

WH2XXP, as reported by VK5ABN

 

wh2xxp-zl2bcg-102416

WH2XXP, as reported by ZL2BCG

 

Ken, K5DNL / WG2XXM, reported that 56 unique stations decoded his signal, including VK4YB:

wg2xxm-vk4yb-102416

WG2XXM, as reported by VK4YB

 

Ron, NI7J / WH2XND, reports that he received WSPR decodes from EJTSWL for the first time during this session.  Ron reported yesterday that he was using a different antenna but that was apparently a misunderstanding.  He indicates that his “…antenna is up at 95 ft with a 220 ft long by 16 ft wide rectangle…total top loading is 480 ft.”  Its essentially the same antenna he has been using, only with a network for 472 kHz.  His statistics follow:

wh2xnd-102416

WH2XND session WSPR activity

 

wh2xnd-ejtswl-102416

WH2XND, as reported by EJTSWL *FIRST TIME REPORT

 

wh2xnd-vk2ddi-102416

WH2XND, as reported by VK2DDI

 

wh2xnd-vk3elv-102416

WH2XND, as reported by VK3ELV

 

wh2xnd-vk2eik-102416

WH2XND, as reported by VK2EIK

 

wh2xnd-vk4yb-102416

WH2XND, as reported by VK4YB

 

wh2xnd-vk5abn-102416

WH2XND, as reported by VK5ABN

 

wh2xnd-zl2-bcg-102416

WH2XND, as reported by ZL2BCG

 

Ken, SWL/EN61, in Indiana reported “…a pretty strong night for all. I ended up with a best -3db on Steve [VE7SL] overnight. Activity very high… had 18 unique stations decoded… another record.”  There seem to be a lot of guys breaking their personal records already this season!

Dave, N4DB, reported a new “best”, decoding VE7SL at -16 dB S/N at a distance of 2338km.

Mike, WA3TTS, submitted the following comments and statistics from his station in Pittsburgh:

“John: I had my EWE to SW overnight. Seems to have been a good NW path so my SNRs would be down 4~5 dB that direction

Four XCR decodes

2016-10-24 08:26 WH2XCR 0.475796 -26 0 BL11je 1 WA3TTS EN90xn 7439 54
2016-10-24 08:14 WH2XCR 0.475796 -27 0 BL11je 1 WA3TTS EN90xn 7439 54
2016-10-24 09:20 WH2XCR 0.475796 -25 0 BL11je 1 WA3TTS EN90xn 7439 54
2016-10-24 09:08 WH2XCR 0.475796 -25 0 BL11je 1 WA3TTS EN90xn 7439 54

17 VE7SL decodes best at -10

2016-10-24 05:04 VE7SL 0.475633 -10 0 CN88iu 5 WA3TTS EN90xn 3489 89

15 VE7BDQ decodes best at -16

2016-10-24 08:00 VE7BDQ 0.475735 -16 0 CN89la 5 WA3TTS EN90xn 3470 89

9 VE7CNF decodes best at -16

2016-10-24 04:14 VE7CNF 0.475780 -16 0 CN89ng 5 WA3TTS EN90xn 3458 90

10 VA7MM decodes best at -16

2016-10-24 04:14 VE7CNF 0.475780 -16 0 CN89ng 5 WA3TTS EN90xn 3458 90

2 WG2XJQ decodes best at -19

2016-10-24 08:26 WI2XJQ 0.475633 -20 0 CN87ts 5 WA3TTS EN90xn 3425 88
2016-10-24 07:58 WI2XJQ 0.475633 -19 0 CN87ts 5 WA3TTS EN90xn 3425 88

XGP was in early around 0230 at -15 so I knew the path would be open. Several XGP decodes at -5 of the 76 total

2016-10-24 11:08 WH2XGP 0.475688 -5 0 DN07dg 5 WA3TTS EN90xn 3227 89
2016-10-24 10:18 WH2XGP 0.475687 -5 0 DN07dg 5 WA3TTS EN90xn 3227 89
2016-10-24 06:20 WH2XGP 0.475687 -5 0 DN07dg 5 WA3TTS EN90xn 3227 89
2016-10-24 10:10 WH2XGP 0.475687 -5 0 DN07dg 5 WA3TTS EN90xn 3227 89
2016-10-24 08:14 WH2XGP 0.475687 -5 0 DN07dg 5 WA3TTS EN90xn 3227 89

I left my antenna pointed SW overnight in the slight chance of a VK detection….

73 Mike wa3tts”

Neil, W0YSE/7 / WG2XSV, reports that his transmitting success during the evening to the East may have been the result of his radial additions last season.  He submitted the following details and statistics:

wg2xsv-102416c

WG2XSV session WSPR activity

 

wg2xsv-102416a

wg2xsv-102416b

Neil notes in RED on the lower dataset false reports generated due to strong signals and noise mixing in the sound decoder.

Larry, W7IUV / WH2XGP, reported the following in the ON4KST chat this morning:

“Pretty good night here, lots of activity.  Heard (as XGP) 17 (a new record for me) including several east siders…Heard (as IUV) 16, including VK4YB and a few east side. This on westward RX antenna…XGP used east BOG for RX…XGP was heard by 56 (possibly a new record for me) including 4 VK’s, ZL, ZF and lots of east side…[VK4YB] prbly you got clobbered by all the strong east & north signals on the BOG…Did not hear Laurence this time but was heard by him…Think condx overall pretty good in all directions but unsettled with fast moving spotlight”

vk4yb-w7iuv-102416-102416

VK4YB, as reported by W7IUV

 

wh2xgp-vk2eik-102416

WH2XGP, as reported by VK2EIK

 

wh2xgp-vk2xgj-102416

WH2XGP, as reported by VK2XGJ

 

wh2xgp-vk3elv-102416

WH2XGP, as reported by VK3ELV

 

wh2xgp-vk4yb-102416

WH2XGP, as reported by VK4YB

 

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WH2XGP, as reported by ZL2BCG

 

Joe, NU6O / WI2XBQ, was looking for a good night of trans-Pacific openings and it looks like he got it with “4QR, 612khz already 20db out of the noise.” at 0800z.  Joe was reported by four VK stations before morning and added, “Good SR enhancement, vk2ddi 16 min before official SR. Great night, only thing missing was JA”:

wi2xbq-vk2ddi-102416

WI2XBQ, as reported by VK2DDI

 

wi2xbq-vk2xgj-102416

WI2XBQ, as reported by VK2XGJ

 

wi2xbq-vk3elv-102416

WI2XBQ, as reported by VK3ELV

 

wi2xbq-vk4yb-102416

WI2XBQ, as reported by VK4YB

 

John, VE7BDQ, was reported by VK2XGJ and shared two-way reports with VK4YB:

ve7bdq-vk2xgj-102416

VE7BDQ, as reported by VK2XGJ

 

ve7bdq-vk4yb-102416

VE7BDQ, as reported by VK4YB

 

vk4yb-ve7bdq-102416

VK4YB, as reported by VE7BDQ

 

Rick, W7RNB / WI2XJQ, experienced and enjoyable night of reports, decoding sixteen WSPR stations including VK4YB and receiving decodes from 34 unique stations:

vk4yb-wi2xjq-102416

VK4YB, as reported by WI2XJQ

 

wi2xjq-102416a

wi2xjq-102416b

Steve, VE7SL, reported in the ON4KST chat that he “Hrd 19 hrd by 46 over ~90 min session before going to bed..excellent E-W path last night.”  Steve’s extensive reports for VK4YB were detailed under Roger’s entry above.

Toby, VE7CNF, reported in the ON4KST chat that “Last night heard 15. Heard by 40 during 4 hour transmit period.”  Toby’s report of VK4YB can also be found above in Roger’s session detail.

Morning CW was very good with low noise although due to obligations I was forced to QRT before sunrise.  WSPR reports also yielded many CW level decodes and the number of stations received was larger than I can recall in recent times.  My WSPR transmission reports can be found here and my WSPR reception reports can be found here.

wg2xiq-kh6-zf1-102416

WG2XIQ 24-hour WSPR activity

There was a tremendous amount of activity on the band last night with 100 MF WSPR stations observed at 0200z.  Ken, K5DNL / WG2XXM, reported  99 MF WSPR stations at 0300z and 22 transmitting stations in North America.  Thats pretty good for any time of year.  Observed new receiving stations include, VE7EHP, W7CRK, W7RNA, N9VC, and NE4RD.  Welcome aboard!

Regional and continental WSPR breakdowns follow:

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North American 24-hour WSPR activity

 

eu-102416

European 24-hour WSPR activity

 

ar-102416

Central / Asiatic Russian 24-hour WSPR activity

 

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Japanese 24-hour WSPR activity

 

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Australian 24-hour WSPR activity

 

There were no reports from Africa or South America during this session.

Eden, ZF1EJ, reported many of the stations around North America including WG2XKA prior to his QRT for high wind:

zf1ej-102416

ZF1EJ 24-hour WSPR activity

 

Laurence, KL7L / WE2XPQ, experienced more trans-Equatorial activity than I can ever recall since starting to report on a daily basis over a year ago.  Laurence reports a weak glow at the horizon but it did not seem to negatively impact his operation, being decoded by five VK’s and ZL2BCG.  He also decoded VK4YB.  Laurence indicated that the WSPR map looked like 20-meters on a good night.  I agree!

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Glow on the horizon at KL7L / WE2XPQ

 

we2xpq-102416

WE2XPQ 24-hour WSPR activity

 

vk4yb-we2xpq-102416

VK4YB, as reported by WE2XPQ

 

we2xpq-vk2ddi-102416

WE2XPQ, as reported by VK2DDI

 

we2xpq-vk2eik-102416

WE2XPQ, as reported by VK2EIK

 

we2xpq-vk2xgj-102416

WE2XPQ, as reported by VK2XGJ

 

we2xpq-vk3elv-102416

WE2XPQ, as reported by VK3ELV

 

we2xpq-vk4yb-102416

WE2XPQ, as reported by VK4YB

 

we2xpq-zl2bcg-102416

WE2XPQ, as reported by ZL2BCG

 

wh2xcr-we2xpq-102416a

wh2xcr-we2xpq-102416b

we2xpq-wh2xcr-102416c

WE2XPQ, as reported by WH2XCR

 

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KL7L 24-hour WSPR activity

 

wh2xcr-kl7l-102416

WH2XCR, as reported by KL7L

 

Merv, K9FD/KH6 / WH2XCR, received reports from four JA’s, five VK’s and a host of stations across North America.  He also decoded four VK’s.  It was a very good night in the Pacific which has become typical:

wh2xcr-102416

WH2XCR 24-hour WSPR activity

 

vk3elv-wh2xcr-102416

VK3ELV, as reported by WH2XCR

 

vk3hp-wh2xcr-102416

VK3HP, as reported by WH2XCR

 

vk4yb-wh2xcr-102416

VK4YB, as reported by WH2XCR

 

vk5abn-wh2xcr-102416

VK5ABN, as reported by WH2XCR

 

we2xpq-wh2xcr-102416a

we2xpq-wh2xcr-102416b

WE2XPQ, as reported by WH2XCR

 

wh2xcr-7l1rll4-102416

WH2XCR, as reported by 7L1RLL4

 

wh2xcr-ja1pkg5-102416

WH2XCR, as reported by JA1PKG/5

 

wh2xcr-ja1pkg-102416

WH2XCR, as reported by JA1PKG

 

wh2xcr-jh3xcu-102416

WH2XCR, as reported by JH3XCU

 

Jim, W5EST, presents, “CW READABILITY: WHAT DOES WSPR SNR TELL US?”:

“Skilled workers know their tools. In the 630m toolbox, favorable WSPR decoder reports of SNR help indicate when CW is likely to reach and exceed the human auditory threshold so a distant operator can copy it. If -13dB WSPR SNR in 2.5KHz bandwidth is a nominal threshold for copying CW, what does that mean?  http://njdtechnologies.net/101816/

Surely QSB matters, doesn’t it? QSB can garble characters, or lose words or even whole transmissions. 630m QSB often can reduce CW readability from Q5 level or even prevent CW copy.  Today, I consider how the WSPR decoder appears to respond under QSB conditions.

When an approximate SNR threshold for CW has been blogged here, it’s instantaneous SNR (short-interval SNR). During each given short interval for which CW copy is characterized, steady signal and steady noise level are assumed.  How does SNR dB from the WSPR decoder relate to instantaneous SNR?

As we know, each WSPR transmission lasts about 110 seconds in its two-minute slot regardless of transmission percentage TxPct.  I have tested the WSPR decoder here using the steady daytime WD2XSH/15 ground wave signal at 10 miles distance while varying my noise canceller to inject or remove large amounts of local noise for differing shorter lengths of time on different 110 second test runs.

The SNR values reported by the decoder on my different test runs* suggest that it continually accumulates signal power and noise power respectively, after which the accumulated signal power is divided by accumulated noise power and converted to dB. In other words, many different graphs of varying signal and noise power could lead to the same measured SNR value.

This gets us to the question, “What does this tell us about reported SNR behavior in the presence of QSB?”  Indeed, the QSB that truly hurts CW readability is that which takes the instantaneous SNR below the CW auditory threshold repeatedly and/or persistently during a typical CW transmission.

In my opinion, WSPR SNR values taken alone will lead you to optimistically predict CW readability when you use those values in QSB conditions where the QSB is fading in and out several times in the 110 seconds.  Since the WSPR decoder does not characterize QSB (as far as I know), you’re on your own when trying to predict CW readability from its SNR values alone.  Going to CW on 630m customarily involves QSY away from the WSPR band. At a 630m station, the operator may find a middle-of-night switchover to CW more than something to just lightly undertake.

If QSB depresses the instantaneous SNR below the CW auditory threshold repeatedly and/or persistently, then CW readability plainly suffers.  A numerical example also suggests this general conclusion and adds some local color, next.

Suppose 630m noise is relatively steady in a 2.5KHz bandwidth and the average signal power suffers QSB every other five seconds (50% fade-up, 50% fade-down)–alternately taking instantaneous SNR from -6 dB down to -20dB where your CW ear can’t copy and then repeating SNR up-down that way.  I calculate that the 110 second SNR will come out about -9dB**, which is 4dB above a nominal -13dB CW threshold.Meanwhile the CW readability itself is suffering considerable QSB.

I hope this post has helped shed some light on SNR in a way that can help us even more intelligently use this very useful and sophisticated support tool, the WSPR decoder.  TU & GL!

*NOTE:  Request my test runs data by emailing mrsocion@aol.com .  Actually, SNR could be estimated across 110 seconds any of several ways as listed next. If you know how the WSPR decoder software is actually written in this respect, please let us know.
  — 1. Continually accumulate signal power and noise power respectively.  Divide accumulated signal power by accumulated noise power and convert to dB.
 — 2. Continually divide each short-interval signal power sample by the noise power sampled in the same short interval. Average the short-interval SNR values over 110 seconds, and then convert their average to dB. This method (2) gives essentially the same answer as method (1) provided the noise power is steady. On a night when 630m band noise doesn’t include much rapidly-varying storm noise, noise level is likely to be relatively steady during the 110 seconds due to the expansive patterns typical of 630m antennas.  (Converting SNR samples first to dB and then averaging those dB values would give a different answer and is probably not preferred.)
 — 3. Same as (2) except find the median of the short-interval SNR samples and convert the median to dB. (The median is the middle number in a list of numbers sorted by size.) Converting SNR samples first to dB and then taking the median would give an overall SNR number identical to taking the median of SNR samples and converting that median to dB.
**Figure overall SNR this way:  Convert each 5-second SNR to power ratio S/N = 10^(0.1 SNR).  S/N for -6dB is 0.25 and for -20dB is 0.01.  The average is about 0.13=(0.25+0.01)x50%. The overall SNR dB estimate would be 10log10(0.13)=-8.9dB, far above nominal -13dB CW threshold while actual CW readability itself suffers under QSB.”

Just an update on the possible changes to this blog:  plans have hit a bit of a snag but I am looking at a few other alternative options in order to reduce the number of files generated in a single day while I continue to maintain the same level of content we are currently enjoying.  I will keep you posted of impending changes.

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