Posts Tagged ‘LF’
630m Crossband Activity Night
630m to HF Crossband |
Our plan is to operate from 0200Z through 0700Z, (1800-2300 PST Saturday). Beginning at the top of the hour, we will both be calling CQ on CW and listening for any callers on HF. CQ's will continue until there are no more callers and will begin again at the next top of hour time slot. This should allow for a wide variation in propagation and the possibility of eastern contacts as the evening progresses.
The frequencies will be:
- VE7SL TX 473.00KHz QSX (listening) 1808KHz (160m) and 3535KHz (80m)
- VE7BDQ TX 474.00KHz QSX (listening) 1813KHz (160m)
If you have not had a look for any 630m stations, hopefully you will take the opportunity this coming Saturday night ... you really do not need any special antennas for receiving on 630m. Many of the stations that I have worked on crossband have been using HF dipoles for low-noise reception.
I'll be promoting this event on several of the reflectors and groups that I regularly enjoy and I also invite you to pass the word on to others. Please watch the blog for further updates.
See you Saturday I hope!
House Number Four – Update
Regular readers will likely recall my early January blog describing the sudden and very unwelcome appearance of a severe noise problem badly affecting my LF reception. I had spent an afternoon D/F'ing the noise source (which was being radiated via the local power lines), only to discover that the residence in question was not occupied ... and has been vacant for the past seven weeks as the noise continued.
The culprit |
Yesterday I noticed that the home was once again occupied and this morning, with radio in hand, I paid visit. It seems that the part-time residents had been spending the past several weeks in Hawaii and had just returned to the house to check up on things. I explained to the owner what I believed to be the problem and, as suspected, it was a CFL light ... a particularly noisy one. Turning the light on and off quickly verified the culprit light and swapping the bulb out for a different one produced no observable noise, as was the case for one that had been left switched-on in the living room.
Whether the offending bulb was just a poorly designed one, a very early manufactured model or one that was about to fail, I do not know ... but I am amazed at the strength of the QRN (and QRM) that the bulb was able to produce at such a distance, about ten properties away!
CFL Crud on LF |
The owner was very concerned that he had unknowingly caused a problem and was very apologetic, as I have found with similar situations in the past.
One of the worst was also a CFL bulb that had actually burned-out and was located in a nearby (three properties away) crawl space. When finally traced, the bulb was heavily charred and had partially melted at the base, yet was still producing an ear-shattering level of crud right into the HF spectrum.
In cases like these, it is often difficult to get an accurate D/F on the signal through normal means since the signal is being propagated via the overhead powerlines. Attempts to D/F the signal almost always point to the closest powerline and not to the signal source. Usually such a noise generator will be confined to your local power grid ... that is, the homes that are powered between the two large power distribution transformers in your local neighborhood. In my case, this limits the search to about 15 homes.
I have found that the best way to tackle this is to make a 'noise map' and to try and measure the noise intensity at a similar point for each property - ie. directly beneath the powerline as it enters the property. This will usually put you at the same vertical distance from the line and will give you a better noise sample that is directly (or not) associated with that property. After mapping this out, if the culprit property is not obvious, then you will at least have narrowed it down to a very few choices. Other types of noise, that can be detected into the VHF range, are probably best detected using normal D/F methods.
After bringing the offending bulb home, I Google-searched the product name and number and came up with a 'product recall' for this particular model.
"According to a Health Canada and Electrical Safety report, the lamp may overheat and melt the enclosure exposing live parts, posing a risk of fire and/or electric shock."
Apparently they were indeed manufactured incorrectly and it's just as well that it was found and removed before causing serious damage!
Once again LF sounds as it should. Hopefully it can remain this way for a long time but with the proliferation on noise-making appliances and 'improvements', I have my doubts.
CLE190 Logs
YJ-200KHz - Victoria Int'l |
CFL Crud |
25 04:00 198 DIW Dixon, NC, USA
24 06:00 200 YJ Victoria - Sidney Island, BC, CAN
24 04:00 200 YDL Dease Lake, BC, CAN
25 07:00 200 UAB Anahim Lake, BC, CAN
24 04:00 201 ZWN Winnipeg, MB, CAN
24 12:00 201 IP Lufthansa, AZ, USA
24 07:00 201 GV Greenville, TX, USA
26 05:40 201 YVZ Deer Lake, ON, CA
24 06:00 203 ZKI Kitimat, BC, CAN
24 06:00 203 YBL Campbell River, BC, CAN
24 06:00 203 TCY Tracy Municipal Apt, CA, USA
24 04:00 204 ZQR Regina, SK, CAN
24 11:00 205 XZ Wawa, ON, CAN
24 04:00 205 COR Corcoran, CA, USA
24 04:00 206 SOW Show Low Regional Apt, AZ, USA
24 04:00 206 EF Castlegar, BC, CAN
24 04:00 207 YNE Norway House, MB, CAN
24 04:00 207 PY Fort Chipewyan, AB, CAN
24 07:00 209 ITR Burlington, CO, USA
24 04:00 209 IB Atikokan, ON, CAN
25 14:00 209 HGT Tusi AHP, CA, USA
24 04:00 209 CYT Yakataga Apt, ALS
24 04:00 211 HDG Gooding, ID, USA
24 04:00 212 YGX Gillam, MB, CAN
25 04:00 212 MPZ Mount Pleasant, IA, USA
24 04:00 212 CGL Juneau, ALS
24 07:00 212 CFV Coffeyville, KS, USA
24 04:00 214 LU Abbotsford, BC, CAN
24 04:00 215 ZAB Edmonton (Intl Apt), AB, CAN
24 11:00 215 TQH Tahlequah, OK, USA
24 04:00 216 GRF Fort Lewis, WA, USA
24 04:00 216 CLB Wilmington, NC, USA
24 04:00 217 EC Enoch, UT, USA
24 11:00 218 RL Red Lake, ON, CAN
24 04:00 218 PR Prince Rupert, BC, CAN
24 04:00 219 ZRS Regina, SK, CAN
24 07:00 220 HLE Hailey, ID, USA
24 04:00 221 QU Grande Prairie, AB, CAN
24 04:00 222 WY Wrigley, NT, CAN
24 04:00 223 YKA Kamloops, BC, CAN
24 04:00 223 AFE Kake Apt, ALS
25 11:00 224 MO Moosonee, ON, CAN
24 04:00 224 DN Dauphin, MB, CAN
25 04:00 225 X5 Vegreville, AB, CAN
24 04:00 225 LWG Lewisburg - Corvallis, OR, USA
25 04:00 227 YAC Cat Lake, ON, CAN
25 12:00 227 MHM Minchumina, ALS
24 04:00 227 CG Castlegar, BC, CAN
24 04:00 229 AKW Klawock, ALS
24 06:00 230 YD Smithers, BC, CAN
24 07:00 230 VG Vermilion, AB, CAN
24 11:00 230 NRN Norton, KS, USA
24 07:00 230 BI Bismarck, ND, USA
24 07:00 233 QN Nakina, ON, CAN
24 07:00 233 OKS Oshkosh, NE, USA
25 14:00 233 LG Seal Beach, CA, USA
24 04:00 233 BWP Breckenridge, ND, USA
24 04:00 233 BR Brandon, MB, CAN
25 12:00 233 AZN Amazon, MO, USA
24 04:00 233 ALJ Hinchinbrook Island, ALS
25 04:00 235 CN Cochrane, ON, CAN
25 04:00 236 ZRJ Round Lake, ON, CAN
24 04:00 236 YZA Ashcroft, BC, CAN
24 04:00 236 FOR Forsyth, MT, USA
24 04:00 238 MPA Nampa, ID, USA
24 04:00 239 OJ High Level, AB, CAN
25 04:00 381.5 SJX St James, MI, USA
Listening for NDBs is a practical way to check out your LF receive capability, should you be interested in developing a good 630m station or in following the nuances of night-to-night MF propagation.
The Low Noise Vertical
There's been a lot of discussion lately on the Yahoo Groups ndblist regarding the "low-noise vertical" (LNV) and it's seemingly excellent performance. Originally described by Dallas Lankford as a good performer from LF to SW, ndblist member, Phil (KO6BB), recently refurbished his earlier built 'LNV', but this time with better feedline and appropriate ferrite cores for the antenna's matching transformers. Some of his description appears below.
To recap. I put the LNV up last spring to overcome the bad IMD products
from local BCB stations I was seeing in the LF region when using the
Roelof Active Whip located about 36 feet AGL. The low noise vertical is
... about 30 feet of antenna, set at roof-line level in this mobile home. As I wasn't sure how well the antenna would perform, I first made it a "Zero Dollar" project, using items I had on hand. Those items included two toroid cores salvaged from a defunct computer PS. I figured that since the supplies operate in the kHz range (as witness what a dirty supply will do to your LF reception), they would be suitable for at least a trial run of the antenna. The balanced feedline was some CAT6 cable I had on hand.
The antenna was a great success, because while it had much lower signal
output than the active whip, it also had ZERO IMD from the BCB stations,
and also less local 'junk' (read noise). The tunable pre-amp I use more
than made up for the lower output of the antenna, after all Signal/Noise
ratio is EVERYTHING in this hobby, NOT how high you can make the "S"
meter read.
The central valley summer heat (often in the 100's) took it's toll on
the CAT6 feedline outer jacket insulation, and while it still seemed to
work OK, I figured that it wouldn't be long before water started to get
into the line and probably degrade it in rainy/foggy weather.
Anyway, I went ahead and ordered the proper toroid coils I needed along
with 25 feet of nice 300 Ohm foam twinlead, and got a couple plastic
boxes to put it all in and made the toroid units. While I was at it ordered
two Amidon FT193-J toroid cores to complete the LNV the way I REALLY wanted to.
Today I installed it all, putting a heavy twist in the feedline to try
to reduce any stray noise pickup on the balanced feedline. I'd say
probably not likely but why take a chance.
OK, here are the results. I took signal level readings of eight 24/7
stations, both before and after changing out the wiring/baluns. The
bottom line is, the new antenna IS an improvement in the NDB range,
tapering off slightly at the high end of the broadcast band. Yeah, it's
'only' a couple "S" units at it's best, but when you're digging for that
weak NDB even 1 "S" unit is a LOT! I'm going to 'assume' 6dB per "S"
unit as I have calibrated the "S" meter of the R-71A receiver.
NOTE: This is 'fuzzy' math, don't take them as 'exact' on the dB readings.
FREQUENCY BEFORE AFTER DIFFERENCE
203 TCY S2 S4 2 S units (12dB)
205 COT S3 S5 2 S units (12dB?)
344 FCH S9+7 S9+15 (8dB)
374 LV S6 S7 1 S unit (6dB)
580 BCB Sta S9+35 S9+38 (3dB)
770 BCB Sta S9+32 S9+32 No Change
880 BCB Sta S9 S9 No Change
1450 BCB S9+10 S9+5 (-5dB)
SO, it looks like the antenna is definitely an improvement where I'm
REALLY interested in it (the NDB band). I could have probably tailored
the toroids for maximum performance, but just used the 81:9 turns ratio
on the outdoors (antenna) and 9:9 on the indoor unit as I'm FAR too lazy
to run up and down the ladder to remove the toroid box, change turns and
retry it again!!!
Some additional notes.
NOTE 1. I have three ground rods dedicated to just this antenna, two 8
footers and a 4 footer. While I was playing with the antenna taking
readings AFTER the work, I disconnected one of the 8 foot rods to see
what effect that had. Signal levels dropped approximately an "S" unit
across the board. So GOOD grounding on this antenna does make a difference!
NOTE 2. I'm NOT exactly sure why it happened, but after the antenna
work here, there was even LESS "local grunge" in the background than
before, even with the stronger signals, making for even better copy on
weak ones than I otherwise expected. . . It DOESN'T make sense to me,
but then, antennas ARE the magic art.
It appears that the grounding plays some importance in the performance of this "non-resonant" aperiodic antenna and the fact that it is non-resonant on the frequencies of interest likely also plays an important part in its good S/N performance.
Several years ago I noticed something similar. My own 10' tuned air-core loop made an excellent receive antenna on 160m, even though the loop was tuned to around 300KHz! Although signal strength was several S-units below my transmitting antenna, the loop was extremely quiet and weak signals were much easier to copy ... In fact I often heard signals on the mis-tuned loop that I could not hear on my resonant half-sloper radiator.
Another ndblist proponent of the low noise vertical is John, in Colorado, who employs three ... one of them a great-looking tilt-over version. The tilt-over is nicely demonstrated in his short you tube video below.
The antennas are also used in combination via his Quantum Phaser, when DXing the broadcast band. The excellent phasing results can also be seen in his short video, while using a wonderful, like new, Hammarlund SP-600 JX.
Dallas Lankford's original article may be found here, while an earlier more encompassing discussion will be found here. A third Lankford article, discussing 'Signal To Man Made Noise Ratios' and comparisons of various receiving antennas, also makes for interesting reading.
Perhaps the 'LNV' might be the antenna you're looking for to boost your LF/MW reception.
To recap. I put the LNV up last spring to overcome the bad IMD products
from local BCB stations I was seeing in the LF region when using the
Roelof Active Whip located about 36 feet AGL. The low noise vertical is
... about 30 feet of antenna, set at roof-line level in this mobile home. As I wasn't sure how well the antenna would perform, I first made it a "Zero Dollar" project, using items I had on hand. Those items included two toroid cores salvaged from a defunct computer PS. I figured that since the supplies operate in the kHz range (as witness what a dirty supply will do to your LF reception), they would be suitable for at least a trial run of the antenna. The balanced feedline was some CAT6 cable I had on hand.
The antenna was a great success, because while it had much lower signal
output than the active whip, it also had ZERO IMD from the BCB stations,
and also less local 'junk' (read noise). The tunable pre-amp I use more
than made up for the lower output of the antenna, after all Signal/Noise
ratio is EVERYTHING in this hobby, NOT how high you can make the "S"
meter read.
The central valley summer heat (often in the 100's) took it's toll on
the CAT6 feedline outer jacket insulation, and while it still seemed to
work OK, I figured that it wouldn't be long before water started to get
into the line and probably degrade it in rainy/foggy weather.
Anyway, I went ahead and ordered the proper toroid coils I needed along
with 25 feet of nice 300 Ohm foam twinlead, and got a couple plastic
boxes to put it all in and made the toroid units. While I was at it ordered
two Amidon FT193-J toroid cores to complete the LNV the way I REALLY wanted to.
Today I installed it all, putting a heavy twist in the feedline to try
to reduce any stray noise pickup on the balanced feedline. I'd say
probably not likely but why take a chance.
OK, here are the results. I took signal level readings of eight 24/7
stations, both before and after changing out the wiring/baluns. The
bottom line is, the new antenna IS an improvement in the NDB range,
tapering off slightly at the high end of the broadcast band. Yeah, it's
'only' a couple "S" units at it's best, but when you're digging for that
weak NDB even 1 "S" unit is a LOT! I'm going to 'assume' 6dB per "S"
unit as I have calibrated the "S" meter of the R-71A receiver.
NOTE: This is 'fuzzy' math, don't take them as 'exact' on the dB readings.
FREQUENCY BEFORE AFTER DIFFERENCE
203 TCY S2 S4 2 S units (12dB)
205 COT S3 S5 2 S units (12dB?)
344 FCH S9+7 S9+15 (8dB)
374 LV S6 S7 1 S unit (6dB)
580 BCB Sta S9+35 S9+38 (3dB)
770 BCB Sta S9+32 S9+32 No Change
880 BCB Sta S9 S9 No Change
1450 BCB S9+10 S9+5 (-5dB)
SO, it looks like the antenna is definitely an improvement where I'm
REALLY interested in it (the NDB band). I could have probably tailored
the toroids for maximum performance, but just used the 81:9 turns ratio
on the outdoors (antenna) and 9:9 on the indoor unit as I'm FAR too lazy
to run up and down the ladder to remove the toroid box, change turns and
retry it again!!!
Some additional notes.
NOTE 1. I have three ground rods dedicated to just this antenna, two 8
footers and a 4 footer. While I was playing with the antenna taking
readings AFTER the work, I disconnected one of the 8 foot rods to see
what effect that had. Signal levels dropped approximately an "S" unit
across the board. So GOOD grounding on this antenna does make a difference!
NOTE 2. I'm NOT exactly sure why it happened, but after the antenna
work here, there was even LESS "local grunge" in the background than
before, even with the stronger signals, making for even better copy on
weak ones than I otherwise expected. . . It DOESN'T make sense to me,
but then, antennas ARE the magic art.
It appears that the grounding plays some importance in the performance of this "non-resonant" aperiodic antenna and the fact that it is non-resonant on the frequencies of interest likely also plays an important part in its good S/N performance.
Several years ago I noticed something similar. My own 10' tuned air-core loop made an excellent receive antenna on 160m, even though the loop was tuned to around 300KHz! Although signal strength was several S-units below my transmitting antenna, the loop was extremely quiet and weak signals were much easier to copy ... In fact I often heard signals on the mis-tuned loop that I could not hear on my resonant half-sloper radiator.
Another ndblist proponent of the low noise vertical is John, in Colorado, who employs three ... one of them a great-looking tilt-over version. The tilt-over is nicely demonstrated in his short you tube video below.
The antennas are also used in combination via his Quantum Phaser, when DXing the broadcast band. The excellent phasing results can also be seen in his short video, while using a wonderful, like new, Hammarlund SP-600 JX.
Dallas Lankford's original article may be found here, while an earlier more encompassing discussion will be found here. A third Lankford article, discussing 'Signal To Man Made Noise Ratios' and comparisons of various receiving antennas, also makes for interesting reading.
Perhaps the 'LNV' might be the antenna you're looking for to boost your LF/MW reception.
The Sun, QRM and CLE189
Courtesy: http://www.solen.info/solar/ |
The cause of the poor propagation was a continual coronal hole stream, from a very large area in the sun's southern regions, as shown here. Now it appears that Coronal Hole 649, in the north, is about to swing into a geoeffective position, and take over the task of disrupting propagation.
CLE189 covered the range of 275-425KHz, with the objective of logging at least one beacon (preferrably the farthest one) on each available channel (150 in total). There are a number of channels that have no NDBs as well as many that get completely clobbered by 1 Kw DGPS (digital QRM) navigation signals along the coasts and the Great Lakes. Additionaly, I was fighting the new noisemaker in my neighborhood, which has yet to be eliminated.
Here is a screen shot of my Perseus receiver, showing the crud being generated...every 60Hz and never constant...drifting in and out of the desired passband continually. The only way to hear signals was to wait until there was a short hole created by the drifters going by. I will be happy when this is issue is finally resolved.
My log shows 111 stations in total, a surprising number, considering the poor propagation and the QRM. If anything, this demonstrates just what a superb receiver the Perseus SDR is:
29 01:26 275 HIN 1053 Whitney - Chadron Muni Apt, NE, USA
31 13:00 277 ACE 1344 Kachemak - Homer Apt, ALS
31 15:00 278 1U 521 Masset Municipal Apt, BC, CAN
31 15:00 280 GYZ 1005 Camp Guernsey - Guernsey, WY, USA
31 15:00 281 CRN 1510 Cairn Mtn - Sparrevohn LRRS, ALS
31 15:00 283 DUT 1867 Dutch Harbor - Unalaska Apt, ALS
29 09:00 284 QD 1014 The Pas Municipal Apt, MB, CAN
31 04:00 286 EKS 600 Ennis - Big Sky Apt, MT, USA
29 09:00 287 ZWG 1168 Winnipeg, MB, CAN
29 09:00 290 YYF 171 Penticton, BC, CAN
29 09:00 292 ZET 518 Devon - Edmonton IAP, AB, CAN
29 09:00 293 MB 18 Mill Bay - Sidney, BC, CAN
29 09:00 295 8C 537 Fairview Municipal Apt, AB, CAN
31 15:00 296 LGD 349 La Grande, OR, USA
29 09:00 299 TV 417 Turner Valley, AB, CAN
29 09:00 300 YIV 1272 Island Lake Apt, MB, CAN
29 09:00 302 QW 705 North Battleford, SK, CAN
29 09:00 304 FH 485 Mc Leod (Whitecourt), AB, CAN
29 09:00 305 YQ 1362 Churchill / Eastern Creek, MB, CAN
29 06:00 308 ZZD 515 Calmar (Edmonton Intl Apt), AB, CAN
29 08:00 311 9Y 421 Pincher Creek, AB, CAN
29 08:00 312 UNT 173 Naramata, BC, CAN
31 08:00 317 VC 873 La Ronge, SK, CAN
29 12:00 320 YQF 469 Red Deer - Penhold, AB, CAN
29 12:00 323 HJH 1393 Hebron Municipal Apt, NE, USA
31 06:00 325 YJQ 312 Bella Bella (Campbell Island), BC, CAN
29 12:00 326 DC 131 Princeton Municipal Apt, BC, CAN
29 07:00 328 YTL 1465 Big Trout Lake, ON, CAN
29 12:00 329 YEK 1414 Arviat, NU, CAN
02 09:00 330 2A 1147 South Indian Lake Apt, MB, CAN
29 13:00 332 POA 2681 Pahoa - Hawaii Island, HWA
29 09:00 333 STI 540 'Sturgeon' Mountain Home, ID, USA
29 09:00 334 YER 1560 Fort Severn, ON, CAN
29 09:00 335 YLD 1813 Chapleau - Devon, ON, CAN
29 12:00 336 LF 1167 La Salle, MB, CAN
29 09:00 337 7D 956 Hudson Bay, SK, CAN
29 08:00 338 RYN 1316 Ryan Field Apt - Tucson, AZ, USA
29 09:00 339 6X 1237 York Landing, MB, CAN
29 09:00 340 YY 2452 Mont Joli, QC, CAN
31 15:00 341 ELF 1710 Elfee - Cold Bay, ALS
29 12:00 342 PFT 1232 Piney - Pinecreek Border Apt, MN, USA
29 12:00 343 YZH 571 Slave Lake Municipal Apt, AB, CAN
29 14:00 344 FCH 857 Chandler - Fresno, CA, USA
29 09:00 346 YXL 1401 Sioux Lookout Municipal Apt, ON, CAN
29 09:00 347 PA 814 Prince Albert, SK, CAN
29 12:00 348 MNC 112 'Mason Co' Shelton, WA, USA
29 09:00 349 GW 1999 'Teock' Greenwood, MS, USA
29 08:00 350 RG 1604 GALLY - Oklahoma City, OK, USA
31 08:00 351 YKQ 1948 Waskaganish, QC, CAN
29 09:00 353 LLD 2684 Lanai - Lanai Island, HWA
29 09:00 355 YWP 1572 Webequie, ON, CAN
29 09:00 356 ZF 995 Yellowknife, NT, CAN
29 09:00 358 SIT 750 Sitka - Biorka Island, ALS
29 09:00 359 SDY 879 Sidney, MT, USA
29 09:00 360 SW 1267 'Roadd' Warroad, MN, USA
29 09:00 361 E3 630 Wabasca, AB, CAN
29 09:00 362 YZS 1807 Coral Harbour, NU, CAN
29 09:00 364 4D 735 Helmet, BC, CAN
29 09:00 365 HQG 1362 Hugoton Municipal Apt, KS, USA
29 07:00 366 YMW 2179 Maniwaki, QC, CAN
29 09:00 367 R5 1038 Pukatawagan Apt, MB, CAN
02 10:00 368 PNM 1402 Princeton Municipal Apt, MN, USA
29 13:00 370 YBV 1169 Berens River Apt, MB, CAN
29 09:00 371 GW 1946 Jarpik - Kuujjuarapik, QC, CAN
29 09:00 372 ZPA 824 Glass (Prince Albert), SK, CAN
29 09:00 373 TF 1191 ARUBA - Pueblo Mem Apt, CO, USA
29 13:00 374 LV 776 REIGA - Livermore, CA, USA
29 09:00 375 BM 1163 Balmoral, MB, CAN
29 09:00 376 YAG 1345 Fort Frances, ON, CAN
29 09:00 377 EHA 1350 Elkhart - Morton County Apt, KS, USA
29 12:00 378 OT 381 EMIRE - North Bend, OR, USA
29 09:00 379 YBE 945 Uranium City, SK, CAN
29 09:00 380 OEL 1297 Oakley Municipal Apt, KS, USA
29 09:00 382 YPL 1461 Pickle Lake, ON, CAN
29 09:00 383 CNP 1146 Chappell, NE, USA
29 09:00 384 3F 792 Ile-a-la-crosse, SK, CAN
29 15:00 385 EHM 1693 Cape Newenham LRRS Apt, ALS
29 09:00 386 HAU 558 Hauser - Helena, MT, USA
02 09:00 387 CAV 1473 Clarion, IA, USA
29 08:00 388 AM 2596 'Picny' Tampa, FL, USA
29 13:00 389 CSB 1275 Harry Strunk - Cambridge Muni, NE, USA
29 10:00 390 HBT 1620 Borland - Sand Point Apt, ALS
29 09:00 391 DDP 3772 Dorado - Vega Baja, PTR
29 12:00 392 XVG 1344 Longville, MN, USA
29 09:00 393 BR 2101 'Depoo' Brownsville, TX, USA
29 09:00 394 RWO 1333 Woody Island - Kodiak, ALS
29 09:00 395 ULS 1342 Ulysses Apt, KS, USA
29 09:00 396 YPH 1923 Inukjuak Apt, QC, CAN
29 09:00 397 ZSS 760 Yellowhead (Saskatoon), SK, CAN
29 09:00 398 3D 965 Cumberland House, SK, CAN
29 09:00 399 ZHD 1371 'Thunder' Dryden, ON, CAN
29 09:00 400 FN 1071 COLLN - Fort Collins, CO, USA
29 09:00 400 CKN 1220 Crookston, MN, USA
29 09:00 401 YPO 1644 Peawanuck Apt, ON, CAN
29 09:00 402 L4 888 Nipawin, SK, CAN
29 13:00 403 AZC 971 Colorado City Municipal Apt, AZ, USA
29 15:00 404 GCR 1185 Glacier River - Cordova Apt, ALS
29 14:00 405 2K 538 Camrose, AB, CAN
29 09:00 406 YLJ 725 Meadow Lake, SK, CAN
29 08:00 407 CO 1157 PETEY - Fountain, CO, USA
29 09:00 408 MW 221 PELLY - Moses Lake, WA, USA
29 10:00 408 JDM 1270 Wheatfield - Colby, KS, USA
29 12:00 410 GDV 860 Glendive - Dawson Comm Apt, MT, USA
29 09:00 412 1W 996 Sandy Bay, SK, CAN
29 12:00 413 YHD 1361 Dryden Regional, ON, CAN
29 09:00 414 GRN 1094 Gordon, NE, USA
29 09:00 415 CBC 3129 Cayman Brac - West End, CYM
29 09:00 417 IY 1508 CHUKK - Floyd, IA, USA
29 09:00 419 RYS 1975 Detroit / Grosse Ile, MI, USA
29 09:00 420 FQ 1422 MONTZ - East Chain, MN, USA
29 09:00 421 VLY 1721 McKenney, TX, USA
Once again, the 10' x 20' loop was employed for the entire affair, surviving two bad wind storms during the listening event.
House Number Four
It seems that if I'm not chasing down noisy power poles or hunting for drifting wireless headsets, both of which have tried their best to tax my 6m reception this past year, I spend several hours each year chasing down delinquent noise generators!
I spent yesterday afternoon searching the neighbourhood for the source of an annoying and disruptive 120Hz hum. Testing my patience for about a week now, the AC buzz has been ripping-into my usually quiet LF reception, disrupting efforts to participate in the latest CLE (189) listening event. Although conditions have been poor, as usually occurs during these events, the signal-shrouding AC hum has made the event a real struggle.
I had been hoping that, whatever the source of the suddenly-appearing interference was, it would disappear as quickly as it had arrived. I had first noticed it several weeks ago, but it would always go off around bedtime and often was not there at all in the evenings...but the past week it has been there 24/7.
Yesterday I had finally had enough and with Sony 2010 in hand, along with its built-in ferrite bar antenna, I tuned the radio to 630m and started walking around the neighbourhood.
The first thing I noticed was that the signal was being propagated along the overhead powerlines and it was difficult to get a direction of the true source...all nulls pointed to the closest line. Walking to the north, the signal gradually became weaker and reversing direction to the south produced an ever-increasing AC hum...progress! I eventually found a corner where the QRN peaked, and walking in all directions from that point saw the noise diminish...getting warmer!
There were four possible homes here that could be the cause of the problem. I spoke with three of the four homeowners, all of whom seemed genuinely concerned about the source. They all let me into their homes and, with radio in hand, look for the source of the (by now) loud buzz. None of the three homes seemed to furnish the nasty noisemaker.
House number four was unoccupied but was, I was told, up until about a week ago. Venturing on to the property, the S9 buzz started to climb and by the time I had reached the porch, the Sony was on the verge of self-implosion...getting very hot now! A knock on the door confirmed that nobody was home but...behind the curtain, there it was...a floor lamp was turned ON!!
With the source now located I could now breath a little easier but unfortunately could not hear any quieter. Hopefully the owners, who go back and forth to the mainland frequently, will return soon and that LF will once again sound as it should.
What could be screwed into that floor lamp? I'm betting on a poor-quality or about-to-fail CFL bulb.
The one on the left is the actual bulb that I removed from a crawlspace, about four years ago, three houses away. It had been creating the same sort of buzz, only louder, as it was much closer. It was not emitting any light whatsoever yet continued to generate noise as well as present a real fire hazard. The house occupants had left it switched 'on' in order to discourage the local otter population from making a winter home in their crawlspace. Somewhere along the line the bulb had failed and started generating large amounts of AC hum.
This one was tough to find, as even several blocks away, it was very loud. It seems that power lines make wonderful LF antennas. I had to make a map showing signal strengths at many locations to find the source... my neighbours have since given me a key to their house, just in case it happens again!
So...what do you think is in house number four?
I spent yesterday afternoon searching the neighbourhood for the source of an annoying and disruptive 120Hz hum. Testing my patience for about a week now, the AC buzz has been ripping-into my usually quiet LF reception, disrupting efforts to participate in the latest CLE (189) listening event. Although conditions have been poor, as usually occurs during these events, the signal-shrouding AC hum has made the event a real struggle.
I had been hoping that, whatever the source of the suddenly-appearing interference was, it would disappear as quickly as it had arrived. I had first noticed it several weeks ago, but it would always go off around bedtime and often was not there at all in the evenings...but the past week it has been there 24/7.
Yesterday I had finally had enough and with Sony 2010 in hand, along with its built-in ferrite bar antenna, I tuned the radio to 630m and started walking around the neighbourhood.
The first thing I noticed was that the signal was being propagated along the overhead powerlines and it was difficult to get a direction of the true source...all nulls pointed to the closest line. Walking to the north, the signal gradually became weaker and reversing direction to the south produced an ever-increasing AC hum...progress! I eventually found a corner where the QRN peaked, and walking in all directions from that point saw the noise diminish...getting warmer!
There were four possible homes here that could be the cause of the problem. I spoke with three of the four homeowners, all of whom seemed genuinely concerned about the source. They all let me into their homes and, with radio in hand, look for the source of the (by now) loud buzz. None of the three homes seemed to furnish the nasty noisemaker.
House number four was unoccupied but was, I was told, up until about a week ago. Venturing on to the property, the S9 buzz started to climb and by the time I had reached the porch, the Sony was on the verge of self-implosion...getting very hot now! A knock on the door confirmed that nobody was home but...behind the curtain, there it was...a floor lamp was turned ON!!
With the source now located I could now breath a little easier but unfortunately could not hear any quieter. Hopefully the owners, who go back and forth to the mainland frequently, will return soon and that LF will once again sound as it should.
What could be screwed into that floor lamp? I'm betting on a poor-quality or about-to-fail CFL bulb.
The one on the left is the actual bulb that I removed from a crawlspace, about four years ago, three houses away. It had been creating the same sort of buzz, only louder, as it was much closer. It was not emitting any light whatsoever yet continued to generate noise as well as present a real fire hazard. The house occupants had left it switched 'on' in order to discourage the local otter population from making a winter home in their crawlspace. Somewhere along the line the bulb had failed and started generating large amounts of AC hum.
This one was tough to find, as even several blocks away, it was very loud. It seems that power lines make wonderful LF antennas. I had to make a map showing signal strengths at many locations to find the source... my neighbours have since given me a key to their house, just in case it happens again!
So...what do you think is in house number four?
Japanese Amateurs To Get 630m!
Courtesy: http://blogs.yahoo.co.jp/sapporo50w |
Add Japan to the growing number of countries now allowing their radio amateurs access to the 630m band. A recent note from JA8JPO and others, indicates that JA stations will have access to the band as of January 5th, 2015. Operation on their new band however, comes with a few provisos.
Operations on 630m will be permitted at 1W EIRP, not as high as some jurisdictions, but adequate for plenty of exciting experimentation and for some DX opportunity. Additionally, there can be no operation if there is a house or an office within a 200m radius of the station, unless it is owned by the station operator. This restriction can be lifted if permission from the home or property owner is received. As well, the station will be subject to inspection by Telecom authorities before the licence is granted. No reason for these additional caveats have been offered as of yet but JA amateurs speculate that it may be for fear of disruption (by radiated harmonics) to broadcast-band reception or with possible interruptions to ADSL modems, still commonly used in rural Japan....time will tell.
In the meantime, it is reported, that hundreds of excited amateurs in Japan are now readying their stations for two-way 630m work, happy to have the band under any restrictions...if only the same level of excitement were seen among Canadian amateurs for their new band!