DX Windows and the ARRL Band Plan

Discussion in 'Discussions, Opinions & Editorials' started by AG6X, Nov 21, 2007.

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  1. AG6X

    AG6X Ham Member QRZ Page

    As some new hams are passing their Amateur Extra exams this may be a good time to revisit the ARRL band plans.  The ARRL and other international entities have established special frequency "windows" that are set aside for special operation.  One such window is the 75 meter DX window that occupies a mere 10KHz  between 3.790 to 3.800MHz.

    For years, a major problem with this DX window is that many operators feel its necessary to crowd the window; operating 1 to 3KHz from the DX window's edge.  Additionally, new operators are being heard rag chewing (and not IDing) within the DX window and are unaware of the DX stations on frequency.  This happened this morning as W5 stations occupied 3.790 for over an hour while UA0 and BY stations were heard calling DX.

    Guys, this is not a witch hunt!  Let's all remember that we are able to stretch our legs to 3.600 MHz now...use this wide open space for ragchewing on 75/80 meters.

    There are other established DX windows that we all should learn and respect...maybe some of these are new to you.  Pick your favorite band and monitor the DX window for the DX we all want to work and if we recognize these DX windows, our favorite bands will be better off for it.

    Take a look at the following link that shows the ARRL band plan along with the DX window locations:


    73's de AG6X
  2. KC2PBJ

    KC2PBJ Ham Member QRZ Page

    Wise counsel! Thanks for the gentle reminder (or as George Patton said, "No, just give me a swift kick in the a**". Operating courtesy prevents total anarchy and chaos.
  3. KJ3N

    KJ3N Ham Member QRZ Page

    Additionally, we have on ocassion (since about Feb of this year) newly minted Generals ragchewing on 3800 or 3801. Learn your priviledges and how SSB signals are generated, boys and girls.

    I have also caught a couple of new Generals working DX well into in the window. Do any of these guys bother to learn where they're supposed to be? [​IMG]
  4. K5RCD

    K5RCD XML Subscriber QRZ Page

    The ARRL list of DX windows only shows two for HF, one at 80 meters, and the RTTY / Data DX window for 40 meters.

    Where do they show the MF DX window for 160 meters ?  

    Hell, the 160 meter DX window is even a question on the Extra written exam.

    Having only a partial list of the DX windows is worse than having none at all. Anybody relying on the ARRL list will assume there is none for 160 meters.

    If ARRL is going to provide such a list, they need to get their act together and do it right.

    This is not meant as a bash against ARRL. I am a member.

    How about some of Y'all providing a complete and correct list of HF / MF DX windows on this thread ?  As a relatively new ham, I am only aware of those two listed on the ARRL site and the one at 160 meters. Aren't there others ?    [​IMG]
  5. AG3Y

    AG3Y Ham Member QRZ Page

    How about some of the other "specialty modes" RTTY, digital, SSTV? [​IMG] Here is the ARRL band plan as it stands, warts and all:


    I'm listening, at the very moment I'm typing this, to a station calling "CQ" using SSB, EXACTLY on top of the 14.230 SSTV frequency as suggested in the ARRL band plan.

    Maybe we should contact our representatives, and do some serious recommending!

    73, Jim
  6. N8YX

    N8YX Ham Member QRZ Page

    Stuff that.

    Break out the Wouff Hong and begin to apply it liberally.

    A good starting point might be with a few selected WinLink PMBO operators...
  7. AG6X

    AG6X Ham Member QRZ Page

    Regarding 160[​IMG]

    Here's what CQ magazine says about the 160 Meter DX window when promoting their 160 contests:

    "Intercontinental DX Window: 1830 to 1835 kHz should be left clear for DX stations for intercontinental QSOs in both contests. This is still voluntary but essential if the contest is to continue to attract rare DX as entries. USA, Canadian, and European stations should refrain from using the window for local contacts. Please stay away from the window edges, too. This is a gentleman’s contest and band, so let’s help make intercontinental contacts happen".

    If you review any contest rules for the big DX contests you'll find specifc verbaige pertaining to proper conduct in the resepective band's window.  Sadly, none of these rules of conduct were followed as MANY stateside stations polluted the 75M DX window during the latest sweepstakes contest.

    Bottom line?  Here is what the IARU says about the INTERNATIONAL BANDPLAN that will take effect January 1st, 2008.  


    The IARU just opened the DX window on 75 to 3775 -3800...they have also added a LOT of DX windows to all of the bands...check it out!!!

  8. G8ADD

    G8ADD Ham Member QRZ Page

    If only!

    That "International Bandplan" includes frequencies that I cannot legally transmit on:

    1.80 to 1.81

    3.80 to 4.00

    7.20 to 7.30

    On the other hand we have seven channels on 5 megs (by notice of variation to Advanced licensees only) [​IMG]


    Brian G8ADD
  9. G0GQK

    G0GQK Ham Member QRZ Page

    Is somebody using the SSB SSTV frequency ? If not, surely its available for anybody ? This is the same thinking as " this frequency has been used by the Dog bone Net for 50 years, just clear off ! Now !"

  10. AG3Y

    AG3Y Ham Member QRZ Page

    These "CQ Contest" rants are often heard right on top of an SSTV picture already being sent.  

    You can see in this first example that the SSB voice started about 15 seconds into the picture, and then went on through the rest of the frame.


    And this second example shows how a carrier ( tuner-upper ) can completely blank out a picture already being transmitted, if the frequency is right


    Note that the interference, in both cases, started AFTER the SSTV picture was already being transmitted.   A lot like MVL's examples of the WinLink lids !

    73, Jim
  11. K2GSP

    K2GSP XML Subscriber QRZ Page

    The bandplan I'm looking at has the dx window on 160 at 1.830 to 1.850 and says unofficial.
  12. KC7GNM

    KC7GNM Ham Member QRZ Page

    Look what you just wrote. It is a suggestion not a rule. There is no rule being broken. If their was no SSTV activity being interfered with then it is perfectly legal. If SSTV was on the freq first then there is a problem.
  13. KC7GNM

    KC7GNM Ham Member QRZ Page

    I see pictures like that all the time on 14.230 and it is because multiple SSTVers are transmitting on top of each other as well. Guess they are just as bad as the SSB guys.
  14. AG3Y

    AG3Y Ham Member QRZ Page

    No argument there, Greg. That has been one of my pet peeves for quite some time. However, you can tell the difference between voice transmissions and another SSTV transmission, because voice will generally not mess up the sync timing of the station being interferred with , and a carrier ( tuner upper ) will inject a solid band of gray, black, or white depending on the frequency of the tone being produced. Conflicting SSTV transmissions will often show two portions of two completely different pictures, if they are being sent with the same protocol ( mode ) or result in a severely slanted pattern during one part of the picture if another completely different sync rate is being received at the same time . ( such as mixing Martin I with Scotty II , for instance ) Here is an example of that, in fact that was my transmission in the top half of the frame that was being QRMmed ( taken off a webcam ):


    14.230 can certainly be a mess at times, and the problems are NOT always a result of an SSTV transmission being QRMmed by a voice transmission! Point well taken.

    73, Jim
  15. KD4IFB

    KD4IFB Ham Member QRZ Page

    What! I cant go there??   [​IMG] I dont think ragchewing should be done there in the window..Our part of the DX window consist of all between 3800 and 3845 . And it should be for that...But to work the contact 3800 is my limit..And I will go there..
  16. WZ9O

    WZ9O Ham Member QRZ Page

    Operating below 3.803 lsb would put your signal below 3.800.
  17. KD4IFB

    KD4IFB Ham Member QRZ Page

    Yea well tell that to the yahoos on 3.799 then that bleed in over on us.. [​IMG]  [​IMG]   My Op. band is 3.800 to 4.000  I will not intentionally interfere with anyone.. But I will go there. [​IMG]  [​IMG]
  18. KB3LIX

    KB3LIX Ham Member QRZ Page

    Operating as a general below 3.803 (LSB) will be a willful violation of section 97.301 (d) where it clearly states that operation by a general is limited to the band between 3.800-4.000.

    Time to study and begin to understand the concept of single side band generation and the spectrum it occupies.


    Yours is a CHICKENBANDER attitude !!!!!!

    I sincerly hope you get NAILED
    You deserve it !!!
  19. K0RGR

    K0RGR Premium Subscriber QRZ Page

    What he is saying is that if you set your rig to transmit on 3.800, LSB, your lower sideband signal will be entirely out of the General band! The (suppressed) carrier will be at 3.800, with your LSB signal from approx. 3797 to 3800. You could, theoretically, if you totally trust the calibration of your rig, operate LSB on 4.000 Mhz. and still be in the band, but none of us would ever wager that our frequency readout is that accurate.

    An Extra operating just outside the general band can certainly generate a strong enough signal that your receiver will still hear him quite a few Khz. away. It's possible that he could be overmodulating or 'splattering' but most likely, he's overloading your receiver. Try turning down the RF gain on you receiver and see if he's still tearing you up. If your radio has a built-in attenuator, that's what it's for - to reduce overload from the kilowatts out there.
  20. KD4IFB

    KD4IFB Ham Member QRZ Page

    Yea I know what hes saying..Thnx..73
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