Unlocking the Mystery: Why the HF Bands Are DEAD

แชร์
ฝัง
  • เผยแพร่เมื่อ 15 พ.ย. 2024

ความคิดเห็น • 131

  • @JohnHill-qo3hb
    @JohnHill-qo3hb 6 หลายเดือนก่อน +8

    I have several comments:
    1. Excellent explanation, I could never get to grips with the solar physics, you made it so simple, will view this video a few times till it sinks in.
    2. Your high school science teacher would be proud of you.
    3. I didn't know that Daleks could get an amateur radio license!

  • @johnorrells3797
    @johnorrells3797 4 หลายเดือนก่อน +2

    20m has been very good in the middle of the night. I am in UK and have been hearing stateside strongly even on short telescopic whip.

  • @Macjohn1419
    @Macjohn1419 6 หลายเดือนก่อน +6

    Aurora activity is a bonus for 6 meters. You can bounce signals off of the aurora and contact stations. A 4-element beam is ideal to get great DX. I’ve been doing it for years.

  • @oldfartonabmx2122
    @oldfartonabmx2122 6 หลายเดือนก่อน +8

    And yes, heard a few fellow farmers complaining their GPS systems were playing up!

  • @youtubeaccount931
    @youtubeaccount931 6 หลายเดือนก่อน +3

    It was weird, there was nothing, then I had one QSO to New Zealand (I'm in California) with 50 watts and a dipole, and then nothing the rest of the time. I'm glad I got on the air, I hadn't played radio in weeks and the aurora got me motivated.

  • @Bill_KL7TC
    @Bill_KL7TC 6 หลายเดือนก่อน +3

    Cool seeing the lights from Australia. Being in Alaska, we see them all the time, but of course this time we had too much daylights and clouds to see them in Alaska. Normal solar flares usually create so much absorption here in KL7, we can't work anyone, much less hear anyone.

  • @mikeZL3XD7029
    @mikeZL3XD7029 6 หลายเดือนก่อน +4

    Hayden,
    I remember this very same thing happened during the sun spot cycle back in 1989.
    At it's peak, the HF and shortwave bands were damn near un-usable, but it got better on the down slope part of the cycle and returned to normality in 1996.
    Interesting things solar cycles.

    • @HamRadioDX
      @HamRadioDX  6 หลายเดือนก่อน

      Hopefully we get some good conditions soon!

    • @Jeff-sp7bg
      @Jeff-sp7bg 5 หลายเดือนก่อน

      In 1990-92 i could talk dx 24/7. Was booming day and. Night

  • @DrWorth-ez5es
    @DrWorth-ez5es 6 หลายเดือนก่อน +1

    Great discussion Hayden! At ~2:36, you mention that HF transmissions can get absorbed by the ionosphere during a geomagnetic storm, so they won't get refracted and therefore no skywave. There's another effect as well as described in the Wikipedia 'Ionosphere' page under the 'Storms' heading. 'During a geomagnetic storm the F₂ layer will become unstable, fragment, and may even disappear completely'. No F2 layer at all is certainly going to make the HF bands go quiet!

    • @HamRadioDX
      @HamRadioDX  6 หลายเดือนก่อน

      Yes very good point! Space weather is very interesting!

  • @kennethausten
    @kennethausten 5 หลายเดือนก่อน +1

    Many newly licensed hams seem to think it's lack of users. Cannot understand why they are not being heard. They got use to vhf uhf fm with Repeaters and some with dmr and dstar . Now HF is a completely different ball game. Many gone back to vhf.. many like me started on HF. HF was ham radio for us oldies. We learnt quickly about propagation. It will eventually get back to normal.

    • @Jeff-sp7bg
      @Jeff-sp7bg 4 หลายเดือนก่อน

      There is no "normal" on HF. I'm a 45 year ham and in the 4 cycles ive been through this is the quietest ive ever seen for such a prolonged period of time. It can be frustrating.

    • @RhettSparrow
      @RhettSparrow 2 หลายเดือนก่อน

      @@Jeff-sp7bgjust getting into amateur radio! If i had known this, i wud have stuck with my uv device and got the hf radio 5 yrs later!!

  • @basspig
    @basspig 6 หลายเดือนก่อน +1

    Just for curiosity sake, I put a digital volt meter across my vertical and horizontal antennas and I noticed that my horizontal antenna accumulated the most DC voltage reaching a high of 87 millivolts. Still a minuscule amount of energy induced into a 70 ft long piece of wire.

  • @Drew_TheRoadLessTraveled
    @Drew_TheRoadLessTraveled 6 หลายเดือนก่อน +2

    I got a new DJI drone the other day.... It is grounded because of solar flares. GPS and 2.4Gh spectrum hopping is affected.
    Outback South Australia is just one big magnetic solar collector.

  • @johndavidson1010
    @johndavidson1010 6 หลายเดือนก่อน

    Thanks for this informative information.
    Yesterday I experienced a strange happening, 20 and 40 meter bands allowed me to make contacts as close as 50 miles! Normal distant contacts were not possible. Other Hams were commenting on ability to make close contacts as well.

  • @erikk77
    @erikk77 6 หลายเดือนก่อน +2

    During the height of the storms I was not able to hear my state police on 155.58. The repeater is about 40 miles to the north. 18 hours later no problem.

  • @DK5ONV
    @DK5ONV 6 หลายเดือนก่อน +12

    I am going to take a Break from HAM Radio for like a Week or so. The Bands going to be super crappy...mostly dead as a Horse. Sporadically there is going to be some openings but not lasting long time. It repeatedly happens on every Year in the month of May.

    • @KD9ZHF
      @KD9ZHF 6 หลายเดือนก่อน +2

      6 meters was open for voice and CW in pockets, but it was strange though - everyone sounded like they were the Borg from Star Trek. I was tempted to call CQ saying that I was Borg!

    • @dannynova3412
      @dannynova3412 6 หลายเดือนก่อน

      40 meter in east side USA is great. Everything else here mud

    • @ChronicAndIronic
      @ChronicAndIronic 6 หลายเดือนก่อน

      Yeah i noticed the same

    • @jeffwright6685
      @jeffwright6685 6 หลายเดือนก่อน +1

      You have 1 more year 2025 is the height

    • @KD9ZHF
      @KD9ZHF 6 หลายเดือนก่อน

      @@jeffwright6685 and then it goes south for how long?

  • @johnwest7993
    @johnwest7993 5 หลายเดือนก่อน

    I recall during the last solar cycle maximum when I was working all over the place with 20 Watts, and the repeaters around the state were keying up one another in weird feedback oscillations to the point where control ops were having to shut them down altogether. The town cop stopped by my shack and asked me why his police-radio communications were so bad when he'd heard that radio communications were great due to solar activity.

  • @vk4uh96
    @vk4uh96 6 หลายเดือนก่อน +4

    Interestingly 10m (28MHz) did not receive the memo! Despite the complete dropout of most HF bands, 10m has been wide open (from VK4 at least) to all continents. Who knows how or why this single band was spared - actually enhanced to this amazing level. VK4UH

    • @paulsengupta971
      @paulsengupta971 6 หลายเดือนก่อน +1

      I would guess as the MUF goes up, the LUF (I just made that up!) goes up as well, so where we can't normally use 80m in the day, I'm guessing we couldn't use up to 15m or 12m, but could use 10m. There's also Sporadic E, there was a lot of that about as well.

    • @Tannerys
      @Tannerys หลายเดือนก่อน

      ​@@paulsengupta971The LUF is real. A radio blackout is when the LUF (lowest usable frequency) is greater than the MUF (maximum usable frequency).

  • @DonzLockz
    @DonzLockz 6 หลายเดือนก่อน +3

    Great info Hayden. Maybe it's a good time for DMR on hotspots.

  • @user-ef3nu1eh7z
    @user-ef3nu1eh7z 6 หลายเดือนก่อน +1

    Here in WI USA our radio been dead starting day before eclipse in april bheavy( 10+s units) static day before and of eclipse then reduced for week and dad since now over month hope turnaround coming

  • @dang48
    @dang48 6 หลายเดือนก่อน +1

    Pretty wild for sure. Last week we went out to get some pictures of the Northern Lights (I'm in Canada), and had to use our GPS. Took longer than usual for our GPS to acquire a satellite so there was the effect mentioned. Watching the lights was amazing.

    • @HamRadioDX
      @HamRadioDX  6 หลายเดือนก่อน +1

      Very cool indeed!

  • @mattstosh6960
    @mattstosh6960 6 หลายเดือนก่อน +1

    Welcome to my almost daily issue here in Alaska. Another reason why logging Alaska is difficult for DX certificates. The Aurora Steel pot. Good video and thank you.

    • @HamRadioDX
      @HamRadioDX  6 หลายเดือนก่อน

      Thanks! I never thought about it that way - how often do you get disruptions?

  • @chairforce0928
    @chairforce0928 6 หลายเดือนก่อน +1

    I was able to chat with a guy that's 90 miles away off of a repeater that's WAY out of line of sight (other side of a large formation of rolling hills) for my handheld GMRS.

  • @vu3mes
    @vu3mes 6 หลายเดือนก่อน +1

    Complete washout on Saturday and Sunday and slightly picking up today..even the regularly heard hf nets were not copy able here in Chennai.

  • @centurionC100
    @centurionC100 5 หลายเดือนก่อน +2

    Because there are few licensed HF operators and 20% listed are dead, 60% don't use their HF license, and the last 20% are only on occasionally. Ham radio is not growing, it is not dead, however it is stagnate and has been for decades. Band conditions have nothing to do with it.

    • @Jeff-sp7bg
      @Jeff-sp7bg 5 หลายเดือนก่อน

      Yes it does have to do with conditions when the HF bands are open 10 meters and 11 meters especially 27.385 calling frequency is absolutely slammed from sunup to sundown and sometimes at night. When theres poor conditions like now. Theres zilch. That makes no sense at all

    • @rrt08
      @rrt08 หลายเดือนก่อน

      Not Dead Yet, just a flesh wound, CQ, CQ…

    • @rrrrsorry8408
      @rrrrsorry8408 หลายเดือนก่อน

      @@rrt08nice , Monty python would be pleased, lol

  • @OldCanadianguy953
    @OldCanadianguy953 5 หลายเดือนก่อน +2

    There’s no mystery. Hams have become lazy, they’re all on FT8 instead of picking up a mic or a key. 73s.

  • @HamRadioPrep
    @HamRadioPrep 6 หลายเดือนก่อน +2

    Great info! 👌🏼

    • @HamRadioDX
      @HamRadioDX  6 หลายเดือนก่อน +1

      Thanks! Hope you enjoy Hamvention 👍

  • @timmotel5804
    @timmotel5804 5 หลายเดือนก่อน

    Good Day and Thank You. Very educational and interesting for this HAM "listener". Best Regards

    • @HamRadioDX
      @HamRadioDX  5 หลายเดือนก่อน

      Glad you enjoyed it!

  • @k6usy
    @k6usy 6 หลายเดือนก่อน

    Worked VK9DX on 6m FT8 with 100w and a HO loop from central CA. The bands are not completely dead you just have to hunt harder for DX.

  • @mattbates6887
    @mattbates6887 4 หลายเดือนก่อน

    This is certainly true, HF propagation and the sunspot cycle does affect activity when the bands are dead. But there are other reasons worth a mention. When you factor in digital modes such as FT8, DMR , and modern SDR rigs it all becomes very clear indeed. A lot of Hams have moved over to DMR now, given up calling CQ on HF preferring instead to stare at the bandscope, and if they see no activity switch the rig off. Plus the HF bands are very noisy now in most urban areas, so weaker signals get buried in the noise, and you just can't hear them. Finally contesting seems to have become more popular over recent years, so for a lot of Hams they only operate during contest activity, which decades ago wasn't an issue. Back then, Hams held nets and regularly talked to one another on 160, 80 and 40 in the evenings during the week, even in periods of high sunspot activity as I remember. Ham radio was the first social network for radio technically minded individuals, to get together on air and discuss radio. Ham radio has changed so much now, from what it was decades ago, you're bound to get less activity on air.

  • @oldfartonabmx2122
    @oldfartonabmx2122 6 หลายเดือนก่อน +3

    Was 6 meters any good? (don't have a 6M antenna yet so idk ?!)

    • @HamRadioDX
      @HamRadioDX  6 หลายเดือนก่อน

      Yes 6m was good via auroral propagation. Yagi or directional antenna is really needed, pointing south

    • @gavindouglas5581
      @gavindouglas5581 6 หลายเดือนก่อน

      Zl1gam bad on 80 and 40 metre band

  • @dustyroaddestinations
    @dustyroaddestinations 6 หลายเดือนก่อน

    thanks so much for this video - I'm basically VERY new at HF and even though there were questions on the test about this it has been difficult to udnerstand and put into practice. I did a POTA last weekend and it took 4 hours to be able to activate the park I was in and that included FT8 and SSB - I wanted to do it totally with SSD but I just couldn't hit 10 but at least with the handful of FT8 I was able to do it. It was brutal to say the least...

    • @HamRadioDX
      @HamRadioDX  6 หลายเดือนก่อน +1

      No problems glad it helped! Good luck on your next activation

    • @dustyroaddestinations
      @dustyroaddestinations 6 หลายเดือนก่อน

      @@HamRadioDX This weekend was pretty rough too - might have been my antenna...

  • @AdamDeal-KF0PRI
    @AdamDeal-KF0PRI 6 หลายเดือนก่อน +1

    It's quite amazing how the sun can be our friend one minute and then next our arch enemy!

  • @jamesalles139
    @jamesalles139 6 หลายเดือนก่อน

    thanks for the clarity, and kudos for the reference to Dr. Skov

    • @HamRadioDX
      @HamRadioDX  6 หลายเดือนก่อน +1

      Tamitha is the go-to for this kind of stuff!

  • @shanerorko8076
    @shanerorko8076 6 หลายเดือนก่อน

    I checked 7mhz on Saturday, it was pumping better than usual in my opinion, I don't know why people were saying HF was dead? Maybe the DX was down but NVIS was fine.

  • @jplewis01
    @jplewis01 6 หลายเดือนก่อน

    Pay attention to the BZ index as well. I negative value can indicate a stronger negative interaction of the Storm with our magnetosphere...

  • @jimgraham6722
    @jimgraham6722 6 หลายเดือนก่อน

    FT8 and JS8 40 and 17 still going somewhat though lower levvel absorption playing havoc. As the lower layers recombine more quickly they should unmask still highly refractive higher layers leading to some good DX off the back of this.

  • @yclept9
    @yclept9 5 หลายเดือนก่อน

    It all happens every day, just over a smaller frequency spread. On 40m, it's open worldwide in darkness, and goes local during the daytime. Why? The ionosphere is always ionized enough to reflect 40m signals back to earth. The radio wave excites an ionized +- pair, which moves and then reradiates the signal a quarter cycle later, inducing a height-dependent delay that does the reflection. In the daytime, the sun ionizes down to lower altitudes, where the mean free path is smaller, and the +- pair collides with something before it reradiates, and the radio wave is turned to heat (absorbed). Higher frequencies survive shorter mean free paths, and even higher frequencies don't reflect at all. So it's always 3 regiemes: absorbed (low freq), reflected (medium freq), unreflected (high freq). Exceptional solar activity ionizes deeper into the atmosphere, turning everything into daytime low frequency. Normal solar produces reflections at 20m and absorption at 40m daytime, and reflections at 40m and no reflection on 20m nighttime.

  • @kurtzFPV
    @kurtzFPV 6 หลายเดือนก่อน

    I did pick up a new country on ft8 40m yesterday, though it hasn't been confirmed yet.

  • @roberthopkins8089
    @roberthopkins8089 6 หลายเดือนก่อน

    Still working some dx on 11 mtrs from the uk tonight... All short stuff... North Italy Poland and Germany... Great for groundwave as well being quiet.

  • @IainDavies-z2l
    @IainDavies-z2l 5 หลายเดือนก่อน

    Are they? I get quite a lot on the SW bands.

  • @moozoowizard
    @moozoowizard 6 หลายเดือนก่อน +1

    Carrington Event was estimated to be an X45 flare. The largest of the recent bunch was X5 something. Its a log scale. X45 is 10^40 times stronger than an X5 !!!!

    • @HamRadioDX
      @HamRadioDX  6 หลายเดือนก่อน +1

      Imagine if that hit us - ouch!

  • @dxer22000
    @dxer22000 6 หลายเดือนก่อน

    some of the Australian MW frequencies also crashed, with no propagation

  • @1958johndeere620
    @1958johndeere620 5 หลายเดือนก่อน

    That audio clip just sounded like a normal QSO between 2 heavy smokers.

  • @MrFreddarama
    @MrFreddarama 5 หลายเดือนก่อน +1

    Dead? The bands seemed active where im at on 20 thru 6 meters.

  • @NukaVaultReadiness
    @NukaVaultReadiness 6 หลายเดือนก่อน

    Great stuff, and thank you for the deeper explanation!

    • @HamRadioDX
      @HamRadioDX  6 หลายเดือนก่อน +1

      No worries hope it was helpful!

  • @mayomayo7318
    @mayomayo7318 5 หลายเดือนก่อน

    Everyone needs to call, not just looking on the clusters....

  • @remaguire
    @remaguire 5 หลายเดือนก่อน

    Heck, I thought you were gonna say it was FT8!

  • @TheRFResistance
    @TheRFResistance 6 หลายเดือนก่อน

    Nice video mate!

  • @ethzero
    @ethzero 6 หลายเดือนก่อน

    Of course i would test my new SDRplay dx the first night of the aurora in the UK and wondered if i had a faultly unit!
    Quickly discovered that this was the same for my RTL-SDR then shortly after @TechMinds let me know of this unprecedented phenomenon 😂

  • @pixeluser175
    @pixeluser175 6 หลายเดือนก่อน +3

    VHF was great, though...

  • @eddiepiecart6030
    @eddiepiecart6030 5 หลายเดือนก่อน

    An observation.
    You do all the exams, get the best radio and antenna system and when the sun decides, no communications
    EXCEPT for good old 27mhz CB
    No matter what there is always some nong out there on 11 metre band.
    ALWAYS!!

  • @bashkillszombies
    @bashkillszombies 3 หลายเดือนก่อน +1

    For anyone not from Australia your bands seem absolutely dead even at your busiest. I suspect it's because you live in a nanny state with a government that dissuades you from ... well, having any form of fun what so ever, what with anything remotely fun being outlawed or heavily regulated.

    • @HamRadioDX
      @HamRadioDX  3 หลายเดือนก่อน

      Nope, we live in a great part of the world. People get jealous

  • @drsysop
    @drsysop 6 หลายเดือนก่อน

    AM Radio. Shortwave Radio. CB Radio including the Free Band has been awful last few days here in North America & this storm will continue.

    • @Jeff-sp7bg
      @Jeff-sp7bg 5 หลายเดือนก่อน

      It has been good for the past week now irs back to nothing. Ive been on 38 lsb call freq

  • @321CatboxWA
    @321CatboxWA 6 หลายเดือนก่อน

    Had great backscatter on 11 during storm and arora peak.

  • @stevefox3763
    @stevefox3763 6 หลายเดือนก่อน

    There have been mass ejections bigger than than Carrington event but earth dodged them as they were on the other side of the sun.

  • @VK4EA
    @VK4EA 6 หลายเดือนก่อน +2

    Sunday 6m and 10m FT8 was pumping - go figure?

    • @kafostad
      @kafostad 6 หลายเดือนก่อน

      Was plenty of Aurora and sporadic E aurora on 10m here in norway. No problem to work FT8 via aurora ES. Audio is clear

    • @HamRadioDX
      @HamRadioDX  6 หลายเดือนก่อน

      I noticed between VK4 and USA was good. VK4CZ was working them well

  • @lomgshorts3
    @lomgshorts3 6 หลายเดือนก่อน

    There is no mystery here at all !! This has happened many times in the past, just as severe. Hams have come to expect this every Solar Max.

  • @donausmus4281
    @donausmus4281 6 หลายเดือนก่อน +1

    The record auroras are an indication of our own weakening magnetic field and our own inevitable pole shift by 2050.

  • @JoeBorrello
    @JoeBorrello 5 หลายเดือนก่อน

    About 20 years ago I had a sked with K8WPI (now SK) on 40 meter CW, him in Long Island NY and me in Kalamazoo MI (about 1100 km). It was during a geomagnetic storm, and the HF bands were absolutely dead. Since it was a sked I tried anyway. His signal was extremely weak, barely budged the S-meter, but was easily readable because of the quiet bands. RST 519.

  • @TaylorHamRadio
    @TaylorHamRadio 6 หลายเดือนก่อน

    They aren't dead, they're just taking a nap. A really long nap....

  • @sogent56
    @sogent56 6 หลายเดือนก่อน

    Nice job.

  • @MrDschubba
    @MrDschubba 6 หลายเดือนก่อน

    Sounds like Steve and David need to ease up on the ciggies.
    Interesting stuff thanks

  • @evischlee5578
    @evischlee5578 5 หลายเดือนก่อน

    Das Problem ist das man nirgends mehr eine Antenne aufbauen darf.

  • @briankleinschmidt3664
    @briankleinschmidt3664 6 หลายเดือนก่อน

    As opposed to low frequency? No. FM is much better. Most of your radio stations are on high frequency wavelengths because AM suffers so much interference.

  • @DellFargus
    @DellFargus 6 หลายเดือนก่อน

    Aurora Borealis!? At this time of year, at this time of day, in this part of the country, localized entirely within your kitchen!?

    • @HamRadioDX
      @HamRadioDX  6 หลายเดือนก่อน

      Yes champ

    • @DellFargus
      @DellFargus 6 หลายเดือนก่อน

      @@HamRadioDX May I see it?

    • @HamRadioDX
      @HamRadioDX  6 หลายเดือนก่อน

      @@DellFargus All gone

  • @Jeff-sp7bg
    @Jeff-sp7bg 5 หลายเดือนก่อน

    Ive seen the sfi at 220+ and the k was 1 k 1. I heard nothing. Zilch. In my opinion those numbers are worthless

  • @eyeinidas
    @eyeinidas 6 หลายเดือนก่อน

    Like giant solar pimples popping and throwing junk at us.

  • @tmastersat
    @tmastersat 5 หลายเดือนก่อน

    Not if your on gmrs.....

  • @regularguy519
    @regularguy519 6 หลายเดือนก่อน +3

    Yep. It was dead! Yay first!

  • @MightySpaceman
    @MightySpaceman 6 หลายเดือนก่อน

    5:55 I think he needs a throat lozenge

    • @cariboooutlaw4852
      @cariboooutlaw4852 6 หลายเดือนก่อน

      That's Backscatter skip.

    • @MightySpaceman
      @MightySpaceman 6 หลายเดือนก่อน

      @@cariboooutlaw4852 yeah it was a joke

    • @paulsengupta971
      @paulsengupta971 6 หลายเดือนก่อน

      Check out "Aurora Propagation on 6 Meters Keith’s Ham Radio World" - he has a video of turning his antenna from a direct contact to auroral and back again.

  • @jameskaras4345
    @jameskaras4345 6 หลายเดือนก่อน +1

    cq from hell hahahahahahaha

  • @dronenuts1156
    @dronenuts1156 6 หลายเดือนก่อน

    Why is it nobody is talking about haarp? Its even on their website that the experiments can cause auroras, they transmit between 2.8 - 10mhz and amateurs are encouraged to follow along and send signal reports. The experiments were to run 8-10th may coinciding with the auroras. Nobody in amateur radio is talking about this and you all seem to think its a natural phenomenon

    • @paulsengupta971
      @paulsengupta971 6 หลายเดือนก่อน

      Did you not see the CME from the sun? People saw it happen and gave a warning it was going to hit earth.

    • @noimnotarobotcanubeleiveit7024
      @noimnotarobotcanubeleiveit7024 6 หลายเดือนก่อน

      America should stop messing around with the planets atmosphere. It belongs to us all

  • @skyking6989
    @skyking6989 6 หลายเดือนก่อน

    It's ATROCIOUS. I can't even get out on ft8.

    • @Jeff-sp7bg
      @Jeff-sp7bg 5 หลายเดือนก่อน

      Ft 8 doesnt even count

    • @skyking6989
      @skyking6989 5 หลายเดือนก่อน

      @Jeff-sp7bg oh boy here we go..🙄

  • @Philip-KA4KOE
    @Philip-KA4KOE 6 หลายเดือนก่อน

    Activated. Only made 33 qsos via ft8.

  • @odinnthor7795
    @odinnthor7795 2 หลายเดือนก่อน

    Just normal here in Iceland, radio blackout :( 73 de TF2MSN

  • @boydsharp
    @boydsharp 6 หลายเดือนก่อน +1

    I was able to make three 6M contacts on FT8 over the weekend. Saw on the spotter that some areas of the USA was open down your way.

    • @HamRadioDX
      @HamRadioDX  6 หลายเดือนก่อน

      Yeah it was open the following morning here (well not here but in Northern VK)