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Author Topic: 7040 Jammer  (Read 4905 times)
W7SOM
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« on: May 12, 2011, 08:44:03 PM »



I can find an internet post at radioreferance.com  (works best to google 7040 jammer) that discusses this carrier.  He shows up on or near 7040 quite often.   The post at radioreference.com is 3 years old.  Does anyone know anything new?  He's taken over the 7040  frequency at times.

John W7SOM
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K0OD
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« Reply #1 on: May 12, 2011, 10:25:09 PM »

Why don't you move to 7039 or 7041?

Seriously, 40 meters is shared with many broadcast, military and other services from around the world. The area around 7040 used to be home to many Russian single letter beacons. The famous V-beacon on 7002 was located near Tashkent (I spent a lot of time DFing it when I had a phased vertical array). WSPR is around 7.039 as I recall. Could it be the carrier of an AM broadcast station far away? In that case the frequency might be precisely on 7.040.000 (get someone with frequency measuring experience to measure it).

How loud is it? Is the signal always on precisely the same frequency? (a ham wouldn't likely be). Does it drift?  Does it ever ID (some carriers do). When do you hear it? If you hear it near high noon it is probably within 500 miles. In the evening or at night it could be almost anywhere.   

From what is said elsewhere, it doesn't sound like an intentional jammer.
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W7SOM
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« Reply #2 on: May 13, 2011, 07:56:58 AM »

K0od

Thanks for you comment.

Yes I do move to other frequencies. So if there were ten of them, I guess you could give in to the bullies and keep avoiding them.  If it happened on W1AW's frequency, you can bet the jammer would be found. It is on a qrp calling frequency,  and I would like to use that frequency, but I don't loose any sleep by moving elsewhere.  

My interest in this is human.  Why would someone do this?    I'm pretty sure its local here in Washington State or at least in a Western State.  It's loud and wide. It seems not to be heard outside of the West Coast, but I'm not sure of that.

There is no doubt whatsoever that it is intentional or there is senility or ignorance involved.   It the same frequency and it appears on a regular basis.  It is not someone tuning up, it is someone putting on a carrier for 3-5 minutes, then quiet for a while.  Does't sound like foreign broadcast -no QSb at all.  No drifting.   I don't track this so I can't tell you how ofter the jammer is on, but other hams have noted it.  I hear him about half the time I am on 40 cw.

73s all

W7SOM
« Last Edit: May 13, 2011, 08:29:56 AM by W7SOM » Logged
KB2FCV
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« Reply #3 on: May 13, 2011, 01:40:48 PM »

The area around 7040 used to be home to many Russian single letter beacons. The famous V-beacon on 7002 was located near Tashkent

Those are still there! I routinely here the C and D beacons when on my Rockmite

But back to the topic, while I haven't heard any jammers on 7040, there is a TON of digital modes in the area (which sucks because all my QRP crystals are on 7040...)  Have you ruled out anything in the house causing the interference? I had one computer that threw carriers all over the place. Our TV puts out some sort of sweeping interference that always seems to find right where I want to operate! As other stated we also share the bands with other services. If you can listen to 30m, you'll hear a digital mode right at the bottom of the band  that is not amateur radio!
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K0OD
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« Reply #4 on: May 13, 2011, 02:23:51 PM »

The most famous Russian beacon was the one on 7002 that sent V's in Morse over and over. You'd occasionally hear American's "yelling" at it, thinking it was some "jammer" down the road. Occasionally it would collide with a rare DXpedition. But the world pretty much learned to stay clear of 7002. It was a wonderful indicator of openings, long or short path, to central Asia. I still have some tapes I made of it and some charts showing its strength as the sun rose and set in Tashkent. Really a lot of fun. But it's been gone for about 15 years.

I tried to compare the strength of the V-beacon with nearby Russian hams. I guessed that the beacon was running about 100w to a good omnidirectional antenna.

I was surprised to learn that many similar single letter beacons remain around 7038-7039. Their locations are pretty well known. The big mystery is their purpose. Oddly they would sometimes send Morse... by hand or by paper tape!

One person on the web has surmised that those beacons are part of the Russian defense network... A very primitive way to show that parts of Russia hadn't been destroyed in a nuclear attack. His theory was the Russians would launch their nukes when most of those beacons went quiet.

If true, you learn to love those beacons! 

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N3QE
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« Reply #5 on: May 13, 2011, 02:33:10 PM »

More than a couple years ago, it could be as others suggest an unmodulated AM carrier from a SW Broadcaster or a broadcast jammer.

Today, a solid carrier is most likely an unattended digital station gone awry. Most interfering carriers from  modern TV's or computers is less than stable (in my experience) and don't sound like a solid carrier.

I have gotten postcards from OO's, telling me that me operating CW on or near 7040 has caused interference to some kind of automatic digital beacon or PSK31 station. A little weird (I understand them not wanting to name the call of who I was interfering with, but I don't actively avoid beacons and know little to nothing about the automatic unattended stations and their patterns so I don't know exactly who I was interfering with. Much less why they would camp out on 7040. Maybe European? They think of 40M CW differently than we do.)

I do hear CW beacons on 17M and higher and can at least decode their calls to know who they are.
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NO2A
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« Reply #6 on: May 13, 2011, 03:03:33 PM »

Not sure if your qrp radio covers above 7100,but if it does the frequencies in that part of the band are good for qrp operation.I`d like to see improved band plans for digital and cw ops. Seems like the two modes are in each other`s way too much.
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W7SOM
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« Reply #7 on: May 13, 2011, 05:03:48 PM »

Thanks for all the comments.

Because I operate around 7040 I have heard all the stuff mentioned above.  PSK -31 is just below 7040,  and of course the Russian letter stations have been around for years.  No, its not something in my house or ham shack.  Other hams in the PAC NW hear it loud and clear, so if its coming from my house or station, I'm either senile or mad!  Guess that can't be ruled out.

Anyway, this is a very pure note - not modulated that I can hear.  I suppose it could be modulated but I can't hear it and I don't have the right equipment to analyze it.

There are hints that it is intentional.  It  seems to start up after you begin a QSO, but not regularly.

It's unlikely to be far away.  No QSB whatsoever, and very strong.  I could be wrong but I'm only getting reports of hearing this from Oregon and Washington, so far.

yes 7100 and above is a great spot to go especially when the contests are hot and heavy.

Now that I've posted my comments I've haven't heard the jammer.  So now I know how to make him go away.

John W7SOM
« Last Edit: May 13, 2011, 05:52:41 PM by W7SOM » Logged
K0OD
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« Reply #8 on: May 13, 2011, 06:16:57 PM »

"Now that I've posted my comments I've haven't heard the jammer.  So now I know how to make him go away."
  Do you hear him with your radio off? Smiley

-----------------------------------
Seriously (again), I doubt anyone has been intentionally jamming the QRP calling frequency (of all frequencies) for three years.

I've had my Flex-5000, which has a built-in scope and my 43' vertical on 7040 all day. My desk where I work is 15 feet away. I've heard many different carriers come and go. It is a very popular frequency and I imagine that many ops test crystal controlled homebrew transmitters there. As I write, 40 should be opening to the west coast. If one station is transmitting a jamming carrier throughout the evening, I'll know it.

One more thing: consider that the interfering carrier might be a harmonic from 80 meters or 160.

N3QE said:
Quote
I have gotten postcards from OO's, telling me that me operating CW on or near 7040 has caused interference to some kind of automatic digital beacon or PSK31 station.
That would really make me mad. I presume the "unattended digital beacon" is WSPR, but such stations have to be attended, theoretically, but often aren't. How would the OO know you were interfering with PSK, unless he got a complaint? Big deal if you were interfering with a WSPR beacon. They often transmit non stop for hours. They're certainly not a priority use of a key frequency. Morse was on 7040 (and saving lives) 100 years before WSPR.
 
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N3UPM
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« Reply #9 on: May 13, 2011, 09:03:10 PM »

Isn't 7040 also the RTTY DX frequency? Thought that was why many are recommending trying 7030 for QRP calling, in line with Europe.
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W7SOM
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« Reply #10 on: May 13, 2011, 10:05:09 PM »

First I've heard of moving the qrp frequency to 7030.  I like it.

No, the Jammer (or whatever it  is)that I was hearing has not been around 3 years.  I've only heard him for a few weeks and he may now be gone. But it seems the FCC found a real Jammer on 7040  three years ago that they shut down.  Hope he is not back.  

Also, I have heard this guy during the day when the skip is shorter. That's another clue that he is here in the Pacific Northwest.

I've heard a lot of vintage radios tuning up on 7040. We have all  heard the tuner's signal vary as he adjusts his LC network.  But none tune up for 5 straight minutes with not a bit of variance in pitch or signal strength. There is zero keying. Its an instant carrier pure in tone with no breaks and no QSB at least here at my QTH. Maybe its a harmonic of an AM station that is somehow not modulated. And its a powerful harmonic.  10 to 20 over s9.   Well he's going to make me look like a monkey because now I can't find him.  On  the other hand, I  have single handedly removed him from the airways.  Where's my trophy?

W7SOM
« Last Edit: May 13, 2011, 10:25:08 PM by W7SOM » Logged
N3QE
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« Reply #11 on: May 14, 2011, 05:15:05 AM »

I presume the "unattended digital beacon" is WSPR, but such stations have to be attended, theoretically, but often aren't.

Thank you for informing me about WSPR. To be honest I'm not sure that I would regard 6Hz wobulation as anything but a "solid carrier". I'm guessing I would need a hi-res waterfall to see that modulation. (My digital experience is limited to some RTTY back in the 80's and a little bit of PSK31 in the past couple of years.)

A similar thread on the QRP group here at Eham, postulating that the "7040 carriers" are WSPR: http://www.eham.net/ehamforum/smf/index.php?topic=67140.0

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N3QE
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« Reply #12 on: May 14, 2011, 05:20:23 AM »

(OO Postcard) That would really make me mad.

I've been getting OO Postcards for decades :-). They really are trying to be helpful and it's important not to take it the wrong way. Until I got the postcard and (a few years later) connected it with this thread, I never woulda thought an apparently unmodulated carrier might be a digital mode. I remember when 40M novice CW segment was packed edge to edge with overlapping SW broadcasters so I regard it as not unnatural to have carriers all over the place that I just ignore.
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K0OD
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« Reply #13 on: May 14, 2011, 08:28:56 AM »

My main gripe here is with hams who assume "some senile geezer" is intentionally QRMing them whenever they encounter crud on "their" frequency. You hear that attitude in every major pileup when someone accidentally reverses his split or a station not involved with the DX tunes up for a few seconds. Here, for example, a South African ham assumes that ancient Russian C beacon is "deliberate interference:"
Quote
I am hearing Carrier continuously on 7038,6Khz and also a  CW signal   _._.  C all the time .
Any idea who is putting these carriers and CW signals on, WSPR is useless in South Africa cos of the deliberate interference.

The worst manifestation isn't in gentlemanly jousting between QRPers and WSPR but rather in the heat of major pileups on 20 where the briefest mistake can set off an escalation of recriminations and jamming among monster stations.

In my opinion intentional jamming is extremely rare. (well, outside 20 and 75 SSB anyway). That "inconsiderate jerk" causing interference is more likely to be a trickle charger in your neighbor's garage or a ham station far away with a family cat dozing on a key. 
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W7SOM
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« Reply #14 on: May 15, 2011, 12:28:25 AM »

What more can be said. I've learned some new things from this group, mainly, that I think I'll be moving my qrp  activity to 7030

At this point I'm concluding  that WSPR is most likely to  be what I am hearing and that nothing I'm hearing is intentional.  There's  plenty of space  on 40 so one has to  jump around a  bit to find your crowd.

73   W7SOM
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