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Elevated-quiet geomagnetic conditions continue plus big storms in the central region of North America make for a noisy night; Generally flat long-haul and domestic propagation; FCC 17-33 published in Federal Register but that DOES NOT mean you can get on the air in 30 days!; W5EST presents: ”Part 2: Smaller Footprint, 40′ High Top-Fed Inverted Delta TX Antenna on 630m”

– Posted in: 630 Meter Daily Reports, 630 Meters

The details for June 14, 2016 can be viewed here.

IMPORTANT REMINDER: Neither 630-meters nor 2200-meters are open to amateurs in the US yet.  Please continue to be patient and let the FCC finish their processes.  Click here to view the proposed “considerate operators” frequency usage guide for 630-meters under Part-97 rules that was developed with the input of active band users.

There is a rumor that has been circulated somewhere on the Internet that claims to allegedly know the UTC notification procedures.  These rumors are lies and seriously jeopardize this process! DO NOT CONTACT UTC TO NOTIFY THEM OF YOUR INTENT TO OPERATE on 472 or 137 AT THIS TIME!  Official procedures are forthcoming – please be patient.  If you find a website or social media post that is perpetuating this bad information, please let me know so action can be taken to rectify the problem.  We can still screw this up!

FEDERAL REGISTER PUBLICATION OF FCC 17-33 which created the 630-meter allocation in addition to rules for both 630-meter and 2200-meters has occurred.  This does NOT mean that the band will open under part-97 rules in 30-days rather it represents another milestone in the overall process.  We still await a “sign off” from OMB to fund the coordination process with UTC, which was agreed upon by estimate prior to the publication of the Report and Order in March.  Once the approval is formally granted, the details for the UTC notification procedures will likely be released.  There is also another comment period somewhere in the mix.   A formal “start date” may not be known for a while.  The timing and order of all of these remaining items is very fluid.  Please continue to be patient.  We are making good progress (Thanks JH3XCU for reporting publication early this morning).

Noise conditions were prolific on 630-meters due to a very active storm system stretching from North to South across North America.  I was actually unaware just how close this system was to my station here in North Texas.  Activity, particularly in the central US, was impacted and stations on either coast probably experienced a difficult time listening through the night.  Propagation appeared to be a bit flat overall but this could have been the result of high noise impacting reception reports.

11-hour North America lightning summary

 

Geomagnetic conditions were at elevated-quiet levels with the Bz showing lots of variability while pointing to the South for much of the session.  Solar wind velocities are at moderate levels, averaging near 460 km/s.  DST values have been variable but have generally remained close to the center line without any real surprises.

 

 

 

Larry, W7IUV / WH2XGP, reported “Moderate noise here, poor prop, low activity, unremarkable nite.”  He provided reports for five WSPR stations and he received reports from seventeen unique stations.  As W7IUV, Larry provided reports for six WSPR stations.

WH2XGP session WSPR activity (courtesy NI7J)

 

Rick, W7RNB / WI2XJQ, provided reports for five WSPR stations and he received reports from sixteen unique stations on a night that was similar to the previous.

Phil, VE3CIQ, reported that he decoded one WSPR station and he received reports from six unique stations, all of which were located within 1000 km.

Mike, WA3TTS, reported, “Only 9 decodes of XXP overnight, best -21. Total of 5 unique stations heard on 630m, no XND decodes on 2200m….QRN was a killer last night.”

Roger, VE7VV, reported that “Last night saw good RX S/N decode reports of my signal, although down from peak nights….Last night’s Wsprnet map showed only 3 RX stns from right on the west coast all the way to the Mississippi, a very big area with no activity.”  Roger also identified first-time reports of his signal by KR6LA, KK6EEW, and N6GN.

Ward, K7PO / WH2XXP, received reports from 27 unique stations.

WH2XXP session WSPR activity (courtesy NI7J)

 

Neil, W0YSE/7 / WG2XSV, was able to perform a comparison test between his transmit antenna and four-turn loop located in his attic.  Neil explains:

“Last night I did another antenna comparison (RXing on 630m) between my TLvertical and a 4 turn loop in the attic (The 4 turns heard better than the 3 turns of the previous night by ~6-8 dB).

Unique by distance comparisons between the TLvertical and the 4t attic loop:

6 UNIQUE spots (of 300 total) were received by the 40 ft top-loaded VERTICAL antenna:

5 UNIQUE spots (of 233 total) were received by the 4 turn attic loop antenna (12 ft wide by 5 ft high rectangle, oriented E-W):

Note that XCR is missing from the loop’s data….

No eastern stations were heard by either antenna, so I cannot yet tell what the radiation pattern is on the loop, altho’ I am guessing that it should favor E-W (I welcome any comments on that).

I need to wait until more stations are WSPRing before I can draw further conclusions. Maybe this weekend will bring more activity. My thanks to all stations that participated this session. Experimentation continues….”

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

Hideo, JH3XCU, provided this link detailing VK -> total JA DX and VK -> JA peak S/N for the session.

Roger, VK4YB, reported “Moderate to high QRN, and the path to WH2XCR was even weaker tonight. No sign of NA, but JA is still good.”  Roger received reports from JA1NQI/2, JA3TVF, TNUKJPM.  He shared two-way reports with WH2XCR.

I operated CW in the evening for more pre-sunset ground wave / skywave transition tests but stopped abruptly when the receiving station to the South indicated that he needed to stop for the night.  I did not operate WSPR overnight but did call CQ again prior to sunrise from 1027z – 1129z.  No additional QSO’s were completed.  It was relatively noisy this morning due to storms to my North but listening was not completely impeded.

Regional and continental WSPR breakdowns follow:

North American 24-hour WSPR activity

 

European 24-hour WSPR activity

 

Asian 24-hour WSPR activity

 

Oceania 24-hour WSPR activity

 

Eden, ZF1EJ, provided reports for three WSPR stations and he received reports from three unique stations.

ZF1EJ 24-hour WSPR activity

 

Merv, K9FD/KH6 / WH2XCR, provided reports for VK3HP and he shared two-way reports with VK4YB.  Roger noted that the path was not as good as previous sessions, however.  Merv received reports from VK2XGJ.  DX report details can be viewed here.  Merv added that “Forecast for next two days [include] thunder boomers and heavy rains, passing front to the north.  Hearing QRN on high bands and having 20 over peaks occasionally on 630.”

WH2XCR 24-hour WSPR activity

 

Jim, W5EST, presents, “PART 2:  SMALLER FOOTPRINT, 40’ HIGH TOP-FED INVERTED DELTA TX ANTENNA ON 630M”:

“Yesterday, I modeled a 70’ tall “▼-shaped” inverted delta TX antenna geometry to multiply antenna current about 2.4x, to increase radiation efficiency on 630m. Now let’s consider a downsized inverted delta TX antenna to achieve a less extensive footprint.

First I tried simply cutting all the dimensions of the 70’ ground mounted antenna roughly in half. Trial-and-error search for such a half-size antenna solution at ground level failed to find something satisfactory.

So, I tried modeling as if to raise the antenna ten feet off the ground.  That worked—to the tune of over 2x efficiency advantage over a top hatted vertical of comparable size and weight.  Putting the inverted delta base loading up ten feet and connecting via a down lead to ground apparently helped reduce the stray capacitance from the antenna to nearby ground.

In the process, I upped the model to a higher current multiplication level 4x-5x.  In other words, the top loaded ▼-antenna was driven with 1.0A RF current at top center 40’ up, and the circulating current in the inverted delta became set at 4-5A RF current.  This arrangement has high Q, which calls for careful tuning and antenna mechanical stability to avoid detuning.

In addition, the higher RF current and the high Q needing stability moved me to specify half-inch copper tubing for the inverted delta portion, with #12 copper wire for the slanted up-lead and for the 10’ ground connection. In practice, the weight of the antenna will need some physical support.  Mounting the LC base loading at 10’ can promote HV RF voltage safety as well.

Today’s four illustrations follow yesterday’s comparative approach—lossy and lossless inverted delta system 40’ high and 60’ wide and this time compared with lossy and lossless 40’ high vertical with 60’ top hat.

In Illustration #1, the lossy “▼” carries about 4.5A RF. Since the variometer inductance is 543 uH, I budgeted 5Ω RF resistance for it. With ground conductivity set to 5 mS/m, the input power 51.91wTPO is diminished by 15.08dBi to yield 2.0725dBw EIRP, or 1.61 watts EIRP.  This antenna presents 53.79Ω input impedance. Again, an omni azimuth pattern features a bulged elevation pattern featuring a 10dB zenith dip. The RF current chart tabulates its calculated delta currents and shows they are anti-phase as desired for wire segments 4 and 5.

Illustration #2 shows the lossless “▼” presents radiation resistance 0.8795Ω / 53.79Ω lossy system resistance, or 1.635% efficiency ratio.  Total radiated power TRP lossless is 0.8549w / 51.91wTPO, or 1.647% efficiency.

Illustration #3 repeats the drill, now for a 40’ vertical of 1.5” copper tube with #12 top hat 60’ long, over 9 mS/m ground to present 52.19Ω system resistance.  RF current distributes itself up the vertical tube, with 1.0A at bottom and 0.58A at top.  508 uH of load inductance has 5Ω resistance budgeted to it.  Input power 52.2wTPO is diminished by 18.39 dBi to yield -1.2133dBw EIRP, or 0.756 watts EIRP.

Illustration #4 continues with the lossless hatted vertical and finds TRP 0.3588w/52.2wTPO for 0.687% efficiency. Similarly, radiation resistance 0.3534Ω/52.19Ω system resistance yields 0.677% efficiency.

Comparing the lossy “▼” with lossy hatted vertical pursues an efficiency ratio this way:

-15.08dBi for lossy “▼” less  -18.39dBi for lossy hatted vertical equals 3.31 dB efficiency advantage for the lossy “▼”. 

That 3.31 dB means a serious 2.14x efficiency ratio even when handicapping the lossy “▼” with considerably lower ground conductivity: 5 mS/m compared to the 9 mS/m for the hatted vertical. That 9 mS/m for hatted vertical can represent a radial field, for instance, associated with 5 mS/m earth. As noted yesterday, folks with other ground conductivities may retune the values and may also use a matching transformer ahead of the ATU.

Can you demonstrate performance by this inverted delta antenna or some other inverted delta antenna design for 630m on limited real estate?  TU & GL!”

 

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