AmateurRadio.com

I admit it. I have an extraordinarily kind next door neighbour!




Ever since erecting a new, much bigger LF antenna several years ago, she has allowed me to run its large, three-wire 100' tophat, directly over the top of her house to a tree on the far edge of her property. As well, she removed her only light dimmer, knowing that it was creating a LOT of nasty RF 'hash' throughout the LF / MF spectrum, seriously degrading my LF reception. To hear the RF noise-signature of a typical light dimmer, listen here, on the ARRL's helpful page of 'household' RFI recordings ... that's just how it sounded here as well!

She recently did a major renovation, which included a new multi-light dining-room fixture and expressed to me a desire to be able to dim it ... oh-oh, I was definitely not looking forward to this.

I did a little web-research and soon learned that some of the most RF-quiet dimmers were being produced by Lutron. One model in particular, claimed to pay special attention to RF noise-filtering and that was the "Centurion", whose smallest model is a 600 watt-capable unit, with a large finned heatsink front plate ... model #C-600P-WH.

I decided to order one from the only dealer I could find in Vancouver that seemed to carry this line of dimmers. The cost was just a little over $40 Canadian (sells for about $25 in the U.S.A.) ... cheap enough if it would do the job!


When the unit came in, I picked it up on my next ferry trip to the city and upon my return, installed it the following afternoon. Before doing the installation, I fired-up the receiving system, tuned to 300kHz, and with the baby monitor set up beside the speaker, took the portable monitor with me.

After installing the new dimmer, I turned on the baby monitor, held my breath ... and turned on the light fixture. Wow ... not a trace of hash could be heard! Adjusting the dimmer from high to low produced no difference in the noise level. I later did a more thorough bandscan and could find no evidence of RFI, on any frequency. The only RFI that I could detect was when placing my Sony ICF-2010 close to the actual dimmer. I was unable to detect any noise further than 6" away from the lights or the dimmer!

So it seems that this model can be highly recommended, for your own home or if you have a next door neighbour 'light-dimmer problem'.

I suspect there are probably a lot of Canadian amateurs still thinking that our new 630m is not very practical for anything other than local two-way contacts.



During the winter 'DX season', this is definitely not the case, as 630m shares many, if not all, of the propagation characteristics found in the lower end of our AM broadcast band. As well, a quick tune through the even lower NDB band on a normal night will reveal dozens of 25-watters, often from over a thousand miles away and with very robust signals.

With no 630m amateur activity yet coming from VE6, VE5 or VE4, it is difficult to get a sense of just how interesting the band could become on these normal nights, or how great it would be on a really good night of propagation. My recent CW contact with the nearest out of province station, VE3OT (Mitch), on a normal night, demonstrates that there is a lot of potential for some really effective two-way work over long distances.

So ... what do signals sound like between here and Ontario? Here is Mitch's CW beacon as heard here on the evening of February 11th, at around 2300 hours local time, using my 10' x 20' loop. I have heard Mitch at even higher levels than this, but his beacon is usually audible here on most undisturbed nights, sometimes as early as 2000 hours local time. His beacon signal runs 200 watts to a 340' circumference loop, from his London, Ontario, suburban backyard.


Even if you are not able to hear Mitch's signal audibly, it should be fairly easy to copy in one of the QRSS CW modes, such as QRSS3 or QRSS10 ... both of which could yield a reasonably quick two-way contact.

Judging from the reliability of the VE3 signal, any activity from the prairie provinces should be even easier to hear. Should any of you in the prairies take up the 630m challenge, I can assure you that you'll be very, very popular out west ... every night!

This blog also provides an opportunity for my initial use of the 'tunestotube' web site. It provides a nice online interface for posting audio files to Youtube, along with an image, or a slideshow. It seemed to work seamlessly and will save me having to link to audio files stored on my own web site, which really eat up what little space I have left.

courtesy: http://www.bing.com/mapspreview

Under most circumstances and on most bands, a contact between VE7 and VE3 would not be considered 'exciting' or 'challenging' ... but Saturday night's CW QSO between myself and Mitch, VE3OT in London, Ontario, met both of these criteria, as it was done on our new 630m amateur band on 475.0 kHz. As such, it represents the first-ever interprovincial contact as well as the furthest contact (2031 miles) between two Canadian stations on the 630m band. As usual, there's more to the story ...

Both Mitch and myself had been alerted to the excellent propagation earlier in the week, when VE3OT's CW beacon had reached S9 levels here for several hours on two consecutive nights ... but any late-night QSO attempts would have to wait until the weekend, when having to get up in the middle of the night would not conflict with Mitch's workweek schedule.

Our first attempt, late on Friday night and 3A.M. for Mitch, found that conditions had deteriorated from midweek's enhanced propagation and the low signal levels, combined with some unseasonal lightning noise, resulted in rescheduling for another shot on Saturday.

Late Saturday night found the band much quieter and propagation much improved, but not as good as it had been earlier in the week ... somehow Murphy always seems to have a hand in pre-planned events, and it's never a helpful one. Mitch's beacon signal was readable here but had a deep ten-minute fade cycle with a short-lived peak before fading out to nothing.

VE3OT at his loop's loading coil

Hoping to take advantage of one of the peaks, we began short two-by-two calls from both sides shortly after 0700Z. I eventually heard Mitch fade up and sending a '339' signal report but my response and '559' signal report to him went unanswered as he had faded away again. I continued the short calls, along with my signal report to him and on the next peak heard him responding with 'RRR and 'QSL'! This time his signal continued to build and we had several short exchanges, with Mitch upgrading my RST now to '549' and with me advising of his stronger '569' signal. As the fade cycle took its grip once again, we exchanged our '73's', 'TU's' and 'SK dit-dit's', while we still had the opportunity ... I can't speak for Mitch, but for me it was a truly exciting contact and one I'll not soon forget.

LF / MF station at VE3OT

I'm sure the opportunity to work again will present itself fairly regularly as we both know that Saturday's conditions were not the best. It will be interesting to try again when signal strengths reach the levels previously heard during the week.

For those of you that worked VE3OT during the recent 630m crossband event, Mitch has put together a very special QSL card!


As the solar cycle winds down, the 'good' nights will happen more often, as will the truly 'great' nights. Hopefully there will be more Canadians on the band to take advantage of what lies ahead.

Hopefully the U.S.A. will soon have the band as well, which will really spark nightly activity. What is really needed right now is more Canadian activity, especially in the western provinces, where nightly CW contacts could be readily made. Time to reach for the solder iron! There are several VE7's, and one VE3, waiting and wanting to work you!

courtesy: http://www.leeszuba.com/projects/

A recent blog posting of four videos showing the installation of a new (Roelof-made) PAØRDT active E-probe antenna revealed that there appeared to be a difference between his earlier model and his latest. It was noticed that the noise ingression levels were different between them, with one showing less noise on LF than on HF, while the other one behaved just the opposite. The newer PFU has the antenna ground isolated from the receiver's ground while the older one does not. Noise coupling, with the new one was higher on HF and lower on LF, which was just the opposite of what was noted with the older unit with its un-isolated ground ... overall LF performance over the newer system was deemed to be better as seen in the final video here.

The only difference seemed to be in the coupling isolation transformer, used in the power feed unit (PFU), likely similar to the one shown at the bottom of this page.

Roleof's transformers are wound on a Magnetics 0W40705TC toroid, whose high mu ferrite has an Al value of ~8350. I mentioned to Roelof that is seemed unusual that the noise levels would be greater on HF than on LF, with the new transformer, as usually it's the other way around when it comes to noise. The changes noted in the video lead to further transformer testing by Roelof, who indicated :

The isolating transformer consists of two bifilar windings on a high mu core. My guess is that the interwinding capacitance spoils the isolation at HF. I have just tested an isolating transformer with two separate windings opposite each other on the tiny core. Sure enough, this solves the feedthrough at HF and VLF performance is not impaired at all.
I have never given this a second thought as I believed it was specific for my location. Never too old to learn!

I have evaluated both transformer types on my spectrum analyser and
found the following.

The current transformer with a twisted bifilar winding is a
transmission line transformer. In a 50 ohm system, it covers 4 kHz (!) to 200 MHz at -3dB. Which is very good.

The new one, using the same core and separate windings is an other
story. It covers just 4 kHz to 8 MHz at -3dB. At 30 MHz the loss is
13 dB. So, excellent for VLF / LF/ MF, it won't do for upper HF.

I will try other core material and see if a feasible compromise is
possible.

To be continued.

further...

I first tried a FT-37-43 toroid with 10 turns for each winding.
This core is suitable for higher frequencies and I expected it to
work better than my high mu (8300) cores.
Nope, it was far worse and at 30 MHz the loss was already > 20 dB.

I reverted back to my magical cores and reduced the number of turns
to 3. This yielded a nice bandwidth (-3dB)from 50 kHz to 50 MHz.

Used in the mini-whip interface, there is no more a difference
between shared grounds and isolated grounds on either VLF / LF or
HF.

Though the lower -3dB point is at 50 kHz, I still have excellent
reception of the Russian Alpha stations between 10 and 15 kHz.
It looks like this transformer is an excellent compromise for this
purpose.

I have often found that in practice, high mu cores are excellent for
wideband transmission line transformers. They are good for
traditional rf transformers as well!

and:

I just have tested a binocular core, the BN-73-202, available from
W8DIZ.

With two windings of two turns each of insulated hook up wire (to
keep interwinding capacitance low), gives a transformer from 80 kHz
to over 100 MHz. In practice reception down to 10 kHz is still
excellent.

There is no difference between isolated or common grounds either.
The coupling with this binocular core is a little better than with a
toroid. At LF / MW, I don't find any loss at all.

The FT-50-75 will do fine with two windings of 4 turns each.
I have some FT-50-77 cores at hand and will see how they work out.

I am surprised at the wide bandwidth that can be achieved.

and:

I have been testing a FT-50-77 ferrite toroid for use as wideband
isolation transformer.

Three turns on the Magnetics (aka magical) cores, give an inductance
of 60 uH. Used as a wideband Isolation transformer, the -3dB
bandwidth ranges from 80 kHz to 50 MHz.

For about the same inductance, the FT-50-77 core needs 6 windings.
Used as wideband isolation transformer, the lower - 3dB point is 100
kHz, the upper is 12 MHz. At 30 MHz the loss is already 8.5 dB.
Though not suitable as wideband isolating transformer, it still can
be used for the range 100 kHz - 3 MHz.

It looks that for good wideband performance the Al value must be >
5000 and the number of turns should be =< 3.

Interesting stuff and the best thing is that it has really lowered
my noise floor!

A summary posting to the RSGB's LF reflector indicates that the new transformer scheme is providing quieter VLF reception and good performance up to 200MHz

For years, I have been using a rf - isolating transformer to
separate antenna and receiver ground.

This is a home made transmission line transformer, consisting of 11
bifilar turns on a small high mu toroid (AL=8300). The inductance is
1.2 mH. The measured -3dB bandwidth in a 50 ohm system covers 4 kHz
- 200 MHz.

It appeared that the isolation was not perfect, due to the
inter-winding capacitance. I have made a new transformer on the same
core with two windings of each tree turns. The windings are opposite
each other on the core. The bandwidth is now 45 kHz - 50 MHz. The
loss is 1.3 dB.

Despite the raise in the lower -3dB point, reception at VLF is much
improved due to lower noise ingress. See attachment.
The screen runs from 1 kHz - 13 kHz. At the right hand the dashes
from the Russian Alpha system can be seen. The white band is with
common ground. Harmonics of the 50 Hz mains can be easily spotted.
In reality the picture will be better,as the sensitivity of the
PERSEUS drops considerable below 10 kHz.

The level of interference on 380 kHz caused by a plasma TV in the
neighbourhood is also much reduced.


An excellent video demonstrating the dramatic effects of isolating the ground in the e-probe antenna system on LF was posted today by PY3CRX. Marcus used the Magnetics hi-mu core with 5 + 5 turns (~ 390 + 390 uh).


For those not having access to the Magnetics material, it looks like the BN-73-202 binocular core is a good performer, from 10kHz - 100MHz. The FT-75 and 77 material also fair well but with differing bandwidths. Cores are available from Amidon as well as from W8DIZ's Kits & Parts.

Friday and Saturday evening's 'Midwinter 630m Activity' event was an interesting demonstration of the band's capability and, by most accounts, a real success.


At first-glance, the propagation gods appeared to favor Friday night but I'm not really so sure as both nights were quite different.

Friday night's extremely high winds and pounding rain played havoc with most of the west coast antenna systems, producing fluctuating SWR's and scopematch traces dancing crazily for most of the night. Geomagnetic conditions were playing tricks on both evenings as well, with the K-index varying between '1' and '4' ... but the sudden dip to '1' on Saturday night was immediately obvious out west. Stations that had struggled to hear any signs of the CQ-ing VE7's suddenly reported aural reception and several quick contacts were made before calling it a night at around 0700Z. Some of the lower ERP stations were never able to crack the Saturday night, generally high, K-curtain, making for a less interesting night.

courtesy: NOAA and http://www.solarham.net/planetk.htm

The highlight of the event was assuredly the activity from Canada's most recent arrival to the band, Mitch (VE3OT) in London, Ontario. A veteran 2200m operator, Mitch recently modified his system to add 630m capability and after a few setbacks, managed to provide a lot of excitement for the crossbanders back east. I'm sure that Mitch's participation has resulted in many eastern amateurs making plans for 630m in the months ahead.

Mitch managed twenty-five two-way crossband contacts, all along the eastern seaboard and as far south as Texas, with his well-heard 200W and 340' backyard loop ... proving once again that you don't need to live in the country with several acres to have a ton of fun on 630m!

VE3OT's Crossband Coverage courtesy: https://www.google.ca/maps

'Backyarders' in VE7 land also had fun, with VE7BDQ, VE7CNF and VA7MM working crossbanders across the PNW and down into California, Utah and Nevada. Although my own system can also fit into a backyard (with kindly help from the neighbours!), it doesn't quite qualify for such description as my antenna is mounted almost over the ocean, with an unobstructed seawater horizon looking towards the rest of North America and to the north.

An interesting observation, noticed during previous events and reconfirmed once again, is the ability of the smaller and lower antennas used by some of the city stations, to propagate much stronger signals into closer regions such as Washington, Oregon and northern California.

On more than one occasion, my signal was reported as 'unreadable' or 'just above the noise floor', while the other backyarders were reported with, sometimes, 'booming' signals. I can only surmise that these antennas offer more high-angled (NVIS-like) radiation compared with my high seaside inverted-L, which likely has a lower takeoff angle ... Saturday night's activity tended to back up this observation. When it comes down to it, I think that all amateur 630m antennas are basically NVIS radiators due to their small size and low height but some are just a tiny bit 'less NVIS' than others!

As conditions enjoyed a short spike late on Saturday evening, NO3M and WA3TTS, both in Pennsylvania, reported good reception of my CQ's and crossband QSO's were quickly completed with both stations, as well as with KB5NJD in Texas. During the short propagation lift, ABØCW, in Colorado, also called in for a quick exchange, indicating that my previously unheard signal had quickly built from nothing to a 549.

Another highlight of the night was a report from Paul, K7CW, from his quiet receiving location in Tahuya, Washington. Paul reports reception of both VE3OT and VO1NA, with the latter being a 'first' from the west coast!

Hi Steve,

Here is my report of things I took part in or observed tonight:

0204Z - Worked VE7SL 473/3566 kHz RST 559.

0209Z - Worked VE7CNF 476.5/3558 kHz Pretty fast QSB RST 529 to 559.

0214Z - 0409Z WG2XSV 476.1 Beacon RST 559. Announced QRT and QSY at 0409Z.

0219Z - Heard VO1NA 477.4 kHz Weak with QSB. I could get or or three characters now and then. Too weak to attempt a QSO. Signal faded to nothing after about 15 minutes.

0225Z - Heard VE3OT 477.0 kHz Weak but much better than VO1NA. Also with QSB fading to nothing. I called several times, but couldn't tell if he came back to me. Strong enough to make a hopeful try. Also disappeared after about 15 minutes.

0241Z - Came across WD2XSH/20 RST 599+ in QSO with WH2XGP RST 589. 474.5 kHz.

0300Z - WD2XSH/20 472.0 599+ now in beacon mode.

0400Z - VE7BDQ 474.0 kHz RST 539 showed up and called CQ twice. I responded on 3555 kHz, but he did not call me back. He then disappeared from the QRG. There was a strong birdie on 475 kHz, but I don't think VA7MM came on.

0409Z - WG2XSV 476.1 Beacon interrupted by announcement of QRT and QSY.

0434Z - Came across VE7BDQ 474.0 kHz again calling CQ. He worked VA7JX, but apparently couldn't hear me.

With that, I took one more look for VO1NA and stopped.

Another interesting night.

73, Paul K7CW

Thanks also to AI8Z in Colorado and W7OIL in Washington for submitting  reception reports!

THE LOGS

From Mitch, VE3OT, in London, ON:

Friday night:

NØFW (OH)
WA3TTS (PA)
KB5NJD (TX)
K4LY (SC)
K3OO (PA)
VE3MM (ON)
N4PY (NC)
WA9ETW (WI)
K9LA (IN)
NO3M (PA)
N2TK (NY)
KK8X (MI)
N2ZK (NY)
N8RR (WV)
VA3SC (ON)

Saturday night:

WD8DSB (IN)
K3UL ( PA)
WB2QMY (NJ)
AA1P (MA)
W2JEK (NJ)
WA3LAB (PA)
K3PA (KS)
NF4C (NC)
W1VD (CT)
WØJW (IA)

From Joe, VO1NA, in Torbay, NF:

N1CGP (ME)
VO1FOG 
VO1BQ
reception reports from around the province, almost all reporting
a positive reception. Also got reports from DF6NM and PAØRDT


From John, VE7BDQ, in Delta, BC. (a description of John's station as well as other VE7's, can all be viewed here):

KGØD/7 (WA)
KU7Z (UT)
VE7KW
WØYSE/7 (WA)
VE7BGJ
W6RKC (CA)
WB2AWQ (NV)
VE7CNF
VA7MM
VE7SL
VA7JX


From Toby, VE7CNF, in Burnaby, BC:

Friday night:

KU7Z (UT)
WØYSE/7 (WA)
VE7KW
VE7BGJ
KGØD/7 (WA)
W6RKC (CA)
VE7BDQ
VA7MM

Saturday night: 

K7CW (WA)
N7BYD (MT)
WØYSE/7 (WA)
VE7SL
VA7MM

As well, Toby was copied on QRSS3 mode in Illinois, late Saturday night.

From Mark, VA7MM, in Port Coquitlam, BC:



From myself, VE7SL, on Mayne Island, BC:

Friday night:

VE7KW
KU7Z (UT)
W6RKC (CA)
VE7BGJ
KB5NJD (TX)
NO3M (PA)
KGØD/7 (WA)
VA7MM
WØYSE/7 (WA)
WB2AWQ (NV)


Saturday night:

K7CW (WA)
VE7CNF
VA7CNF
VA7JX
K7SF (OR)
VE7BDQ
KB5NJD (TX)
N7BYD (MT)
WØYSE/7 (WA)
NO3M (PA)
ABØCW (CO)
WA3TTS (PA)
VA7MM

For an even more detailed description of the weekend event, see KB5NJD's 630m blogs here.

Thanks to all participants ... you have created another successful 630m operating event. Hopefully U.S. amateurs will have access to the band before next winter, allowing all of the two-way activity to take place within the band itself ... how different that will be! Otherwise, another crossband weekend will be in store for the fall of 2016!

This coming weekend will host the "Midwinter 630m Operating Activity", an event that will have the 630m band no doubt sounding very crowded.



Not only will there be a dozen or more U.S. experimental stations in operation, but also six Canadian stations working crossband with other amateurs in both the U.S. and Canada.

Hopefully you will be able to participate as well, by listening for the 630m Canadians and then give them a call on their HF listening (QSX) frequency. Although specific HF QSX frequencies will be part of their CQ, the list below will provide further details regarding where and when the Canadians will be transmitting.

This event should be particularly interesting for amateurs from the central states eastward, as well as the southern states. For the first time, a mid-continent Canadian station will be on-the-air for both nights.

Mitch, VE3OT, will be looking for crossband contacts from his London, Ontario location and looking at the results of his past few weeks of CW beaconing, his 630m signal is being well-heard throughout the eastern half of the continent. For the north-easterners, VO1NA in Newfoundland will be also looking for two-way crossband contacts.

The last time this event was run, dozens of two-way crossband contacts were completed between the 630m Canadians and amateurs on HF. Canadians on the west coast worked as far as KH6 to the west and W3 to the east. With even better propagation looking very probable this coming weekend, the crossband activity could be very exciting!

Canadian Station Schedule

In addition to the crossband activity, the numerous U.S. experimental stations are also seeking your reception reports. These can be either sent to the individual stations (via their qrz.com info) or to myself, for forwarding and posting in the event summary. Several of the old high-powered Californian Maritime stations will also be in operation on CW, just below the 630m band.

More information regarding the weekend's event can be found here in the initial announcement as well as on the ARRL News page here.

As in past events, many of the participants will be found on the ON4KST (2200-630m) Chat page, allowing realtime updates to keep you in the loop ... the more the merrier.

If you are getting ready for the arrival of the 630m band in the U.S., this weekend's event offers a good opportunity to get a 'feel' for the band as well as to participate in the two-way activity with the 'VE' amateurs ... we hope to work many of you this weekend!

A recent posting to Yahoo's 'NDB List Group' by Mike, an ardent NDB DXer in the UK (Sussex), announced the recent completion of his four-part video series describing the installation and testing of a new PAØRDT active antenna.


If you may be contemplating the installation of an active antenna such as this, or perhaps making a start at DXing the NDB band or listening on 630m, then you might enjoy following Mike's journey as he demonstrates that living in the noisy suburbs need not keep you from enjoying the LF/MF bands. Mike includes some interesting tests involving his grounding system versus noise ingress and the results of keeping the electrical main's ground isolated (or not) from the antenna cable's ground.

The PAØRDT active whip is available from PAØRDT himself or if you are handy with a soldering iron, you might choose to build the same antenna in your workshop. These simple yet highly effective receiving antennas are being used successfully by hundreds of listeners all over the world and for their size provide some pretty amazing performance.












Much more information on the PAØRDT e-probe antenna may be found here in a previous blog posting. To see more of Mike's videos, you can visit his interesting Youtube Channel here.