NJDTechnologies

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

Current Operating Frequency and Mode

QRT but I'll be back tonight, WX permitting

SCHEDULED ACTIVITY: CQ 474.5 kHz CW by 1000z through sunrise most days, WX permitting

Average session in North America with variable noise and periods of elevated geomagnetic activity; Did the Perseids impact 630-meter propagation?

– Posted in: 630 Meter Daily Reports, 630 Meters

Band conditions were only average with variable noise depending on when you were listening, what direction you were listening and where you are  located.  Reports for my station suggested both JT9 and CW levels to a number of stations, particularly those found in the southern US.  Activity took a bit of a hit as a few stations are waiting out bad weather.  A major storm system is approaching my station that will likely have me in dry dock for the entire coming week.  I’m not complaining.  We need the rain and my water bill needs a break.

Geomagnetic conditions continue at elevated levels with unsettled periods followed by periods of quiet conditions.  Its my feeling that the magnetic field never really returns to quiet levels in spite of what is being reported.  The Bz has been variable with much of the session pointing to the North but in the last few reporting periods, a South-pointing Bz has been observed again.  Solar wind velocities are averaging 530 km/s, which is an improvement, with a few periods below 500 km/s. DST values continue to suggest disturbed conditions.

planetary-k-index 081216

 

Kyoto DST 081216

 

AUstralian

 

Merv, K9FD/KH6 / WH2XCR, reported yesterday that he may be hearing-challenged until he can resolve a receive antenna complication:

“Well the inevitable happened yesterday,
the last rope that raises the 80 dipole must have busted,
When I fired up on 630M noticed the receive static was
way down,  went out side and the 80 antenna is laying
on the ground.  Either busted or someone cut it, have to see.
This is on the mast that the raising ropes broke several weeks
back.   So in trouble I am..
Will try and figure this all out,  meantime receive on 630 will be
inhibited with the antenna laying on the ground.
More later.
73 Merv”

 

The Maritime Radio Historical Society reports that they have been granted, through a license modification, the original KPH frequencies and will begin transitioning to these frequencies.  Of interest to 630-meter operators, KPH frequencies close to the 472-479 kHz allocation include 426, 460, and 500 kHz.  It does not appear that there are active frequencies within the proposed “amateur” allocation.

A special operating event is being scheduled for Saturday, November 12 (Sunday, November 13 GMT) to commemorate the signing of the Berlin Treaty which created the 500 kHz emergency frequency for the maritime service.  The Marine Radio Historical Society will be active in addition to a number of Canadian stations making cross band QSO’s with amateur stations.  Its my hope that experimental stations will operate their stations, perhaps passing some traffic on CW or digital modes, rather than simply beaconing.  I’m hoping to generate maritime-themed NTS-formatted traffic and pass it to other stations.  This worked well last year and I got quite a bit of good feedback.  The event will only be one night this year, hopefully creating less of a time commitment problem from prospective operators and listeners.

Doug. K4LY / WH2XZO, was decoded here for the first time in months while using 25-watts from the MF Solutions transmit converter driven by the Elad Duo.  He provided the following comments:

“Conditions may not have been as good last night as the previous, based on my reception, but  with about 6 db more power using the MF SOLUTIONS MF Transmit Converter,  WH2XZO was heard by three additional stations.   The transmit converter was easy to set up with my Elad DUO transceiver and has the following specs-

INPUT: 3.66­3.68 MHz (80 meter band) or 4.46­4.48 MHz @ 0.1­1.0 Watts

OUTPUT: 460­480 KHz, 22­25 W into 50 Ohms, non­reactive @13.6V

EFFICIENCY: 85% ­ 93%

DC INPUT: 13.6V @ 2.2A maximum (1.8­2.0A typical)

HARMONIC OUTPUT: minimum 50 dB below fundamental

NO TUNE DESIGN: No special test equipment required, “Plug ‘N Play”!

MODES: CW, MSK, FSK, “WSPR” supported (NO linear modes)

It’s probably a better choice for 630M than the 5 W Chinese linear amp I used the previous nights unless you want to use linear modes such as PSK and SSB.  I bought the Chinese amp a year ago before I knew about the MF Solutions transmit converter or the NJDT Class E amp.

As John cautioned yesterday, the claim by the Chinese amp seller that it is appropriate for 630M is bogus.  Its low pass filter attenuates 160M harmonics, but not the 630M 2nd and 3rd harmonic.  Using the Chinese amp without an outboard LPF, I could hear the 2nd harmonic beating with a local 950 kHz station up to a mile away, but with the MF Solutions transmit converter, there was no indication of the 2nd harmonic even one tenth mile from my home.  For the Chinese amp, I used one of the QRP Labs very inexpensive LPF kits, good for up to 10W and appropriate for the Chinese amp or their own low power 2200M, 630M, and higher frequency transmitters. “

Neil, W0YSE/7 / WG2XSV, reports that his “ears are better than my voice” and provided the following comments and statistics:

“Hearing AK and HI on both antennas last night. Database wont report results for “w0yse/e” which was on the e-probe

(XSV used the TX vertical for both RX and TX as usual)

WG2XSV
Hearing: WE2XPQ, WG2XIQ, WH2XCR
Heard by: N6RY, N6SKM, NO1D, W0YSE/E, W6XY, WI2XBQ

My hearing was better than my reach this session. N01D in AZ was my DX for outbound…”

Regional and continental WSPR breakdown follow:

NA 081216

North American 24-hour WSPR activity

 

EU 081216

European 24-hour WSPR activity

 

JA 081216

Japanese 24-hour WSPR activity

 

VK 081216

Australian 24-hour WSPR activity

 

There were no reports from the trans-Atlantic, trans-African, or trans-Equatorial paths.  UA0SNV was present but no reports have been filed at this time.

In the Caribbean, Eden, ZF1EJ, once again reported my station.  I am a little surprised that he did not decode Doug in South Carolina but  if Eden were using a direction antenna that was directed across North America, it might have been broadside to the southeastern US.

ZF1EJ 081216

ZF1EJ 24-hour WSPR activity

 

Laurence, KL7L / WE2XPQ, reports missing data for KL7L as data file was empty.  Regarding WG2XSV’s signal, Laurence indicates that “you were better on the W1VD probe by avg 2dB but XCR was equal on both”.  He thinks this is the result of trees in line with the probe 100-foot away in the same direction causing the attenuation.   As the rain and his ground wave profiling continues, he adds “marconi is 2dB down on 400ft loop at 40 miles off main lobe by 40deg”:

WE2XPQ 081216

WE2XPQ 24-hour WSPR activity

 

WH2XCr WE2XPQ 081216

WH2XCR, as reported by WE2XPQ

 

Merv, K9FD/KH6 / WH2XCR, began night one of being hearing challenged due to the loss of his receive antenna.  He continues to be heard well enough.  Lets hope a solution can be found soon since the dipole used on receive is also used on HF:

WH2XCR 081216

WH2XCR 24-hour WSPR activity

 

WH2XCR VK2DDI 081216

WH2XCR, as reported by VK2DDI

 

WH2XCR VK4YB 081216

WH2XCR, as reported by VK4YB

 

WH2XCR VK2XGJ 081216

WH2XCR, as reported by VK2XGJ

 

Jim, W5EST, presented this discussion entitled, “PERSEIDS HIGH POINT: LET’S CHECK OVER 630M SNR SEQUENCES”:

“Last night was a predicted high point for the Perseids meteor shower.  Although meteor scatter propagation is not expected on LF/MF/low HF, taking a look at SNR data is useful just in case there’s a surprise. After all, hams and Part 5 experimenters are still learning the vagaries of 630m!  Bottom line: I found no surprise.  Nevertheless, checking SNRs affords us an opportunity to review 630m SNR behaviors on various paths in N. Hemisphere mid-summer.  But first, let’s do a memory refresh about meteor trails.

Particle sizes are less than 1-2 grams. Minority asteroid material is dense-stony or metallic.  Majority of meteors are cometary: low densities, a fluffy conglomerate “dustball.”

Meteors speeds range 11 km/sec (25Kmph) to 72 km/sec (160Kmph). Meteor trails are less than 1 meter diameter, tens of km long. (I interpret this to mean low reflecting cross-section to wavelengths like 630  meters.) Wide range of speeds is due to Earth revolution speed 30 km/sec (67Kmph). On evening side, trailing edge of Earth, meteoroids are catching up and slow. On the morning side, or leading edge of the earth, they’re head-on and fast into the atmosphere.

http://www.amsmeteors.org/meteor-showers/meteor-faq/

If 630m signals mostly reflect from the E-layer, then meteor trails would need to be at least as low in altitude as the E-layer for 630m RF to encounter them, regardless of what then happens or not.  Apparently, meteor trails can often be that low in altitude. Sugar, Oppenheim, Bass, & Chau (2010) studied non-specular meteor trail altitude distributions and durations obtained by 50 MHz high-power radar. Quoting their abstract:

‘High-power large-aperture (HPLA) radars frequently observe nonspecular meteor trail echoes that result from plasma turbulence driven by the intense pressure gradients on the trail edges. This paper analyzes the altitude range, duration, and dependence on head echo strength of nonspecular trails using two large data sets from the 50 MHz HPLA radar at the Jicamarca [Peru] Radio Observatory. Over 2100 trails were used to build altitude profiles that extend from 86 km to 120 km altitude, with 97% of events occurring between 90 km and 110 km. Longer-duration trails tend to form at lower altitudes than shorter-duration echoes. The peak of the altitude distribution of trails lasting at least 5 s can be up to 12 km lower than the peak of the distribution of trails shorter than 5 s. Further, the data show a clear power law relationship for the frequency of both head echo and nonspecular trail power. An improved knowledge of nonspecular trails will allow researchers to better understand meteor trail evolution and their use in monitoring lower thermospheric winds.’  [I’ve bolded the altitudes.] http://onlinelibrary.wiley.com/doi/10.1029/2010JA015705/abstract

https://en.wikipedia.org/wiki/Jicamarca_Radio_Observatory

The WSPR decoder averages SNR, and the WSPR slots are about 2 minutes long. The Perseids meteor shower expected rate –about three trails per minute–was rapid compared to most nights, but still infrequent for WSPR purposes I believe.  If longer lasting meteor trails were mostly horizontal, one would not expect much 630m vertically polarized interaction even if trails lasted more than 5 seconds and could offer enough cross-section to affect 630m. 630m propagation often improves as night progresses, and Perseids sky prominence probably followed a similar arc. Lots of SNR variability exists in 630m SNR already, so meteor effect if any likely would be hard to distinguish.

I tried to see if unusual 630m SNR peaks stand out for particular path directions E/W, N/S, NW/SE, SW/NE.  The TABLE shows very few instances of prominent deep nighttime peaks, and these were not unique where other days’ sequences were available to compare SNR peaks other days.   Some peaks were close enough to eastward station sunrise (SR) to attribute the peaks to pre-SR enhancement instead. To distinguish possibly-important peaks, I eyeball-compared SNR variations with SIQ dB –the SNR interquartile range encompassing the middle 50% of # spots sorted by SNR.

Thanks to John WG2XIQ and Steve VE7SL for their reflector comments yesterday on this topic.

W5EST 081216——————————————————————————————————–

Notes:  No station’s all-night peak SNRs on 8/12 stood out vs. previous week peak SNRs.

‘No seq peaks’ means quick eyeball of SNR sequence no peaks stood out as much as the SIQ dB. “SIQ” is SNR interquartile range encompassing the middle 50% of # spots sorted by SNR.  Occasional peaks -over-sequence occurred other days in last week for stations that showed 8/12 peaks-over-sequence.”

 

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