Strong Plasma cloud in offering on Jul. 2nd for Sporadic E

Must be global warming...

 

Thanks Alex for the Plasma Prediction for Sporadic E propagation. Keep up the good work.

Ronny KG7A

 

Mike,

Acquiring skills, including both technical and people-minded, to successfully communicate despite adverse conditions, including QRM, is an important part of advancing in the amateur radio art. Your opinion may differ, which is OK.

A good notch filter works great on taking out even loud CW in an SSB channel. But not all rigs have them.

Inadvertant and malicious QRM happens on the digital sub-bands too; when a local fires up on JT65 with QRO EIRP aimed at you on 50276 KHz, you can kiss working most any weak signal DX goodbye until they go QRT. This happened to me last night!

If the JT signal is loud enough to hear on speakers, it could be probably be copied as CW / SSB, in far quicker time, which would enable more QSO's or with far more meaningful information throughput. I find it sad if that opportunity is missed.

Ham radio is losing an important social network quality that was about getting to know others on-the-air, not just online (like in these forums). No matter the reason, a move to JT modes en masse doesn't help.

Hope to have a QSO with you some day OTA, any band / mode, but would enjoy CW / SSB more.

73 , John - WØPV

 

I prefer SSB if the path supports it, CW I am way to rusty so if copy requires CW I fall back to digital. But the sun has little to no effect on e-skip, band was open today to east and west and south and I heard 2 stations in EU on JT65 but I was tied up cooking so couldn't sit at the computer to make contacts.

 

Alex,

Its hard to draw a positive conclusion on this. Frankly, I am of the opinion that you wasted peoples' time, including mine.

May I suggest you consult other amateurs before future 'news' items on this subject, which exhort us to get OTA to test a highly speculative hypothesis.

KL7AJ is a fellow amateur who is familiar with issues of propagation. W4HM also. Perhaps you might consult them. I honestly think you need to do so.

73
Chip W1YW

 

Again,

I don't want people to come back to me and say I started some 'anti-JT-65 campaign'. Nope. JT-65 has obvious value. My concern is that it has gained a biased majority of 6m contacts this season, and that was unexpected. The downside of that is it will--and has-- turned off most 'human based' 6m activity and reduced the need for the 4 MHz of 6m spectrum. IMO if 6m continues this trend, you will see at least 3.8 MHz of it disappear in the next 5 years.

The 'social network value' is obviously important. Otherwise I, for one, would just get on Facebook and sell the radios.

K1JT is not aware of this, but the idea of using multiple frequency, monochromatic transmissions for weak signals goes back to work I published in SETI from a conference in 1993.

(Disclosure: I am a 'card carrying' radio astronomer as well; my recent emphasis has been on array development. Last week I announced a new technology called 'aperture engine arrays' at a Quasar Conference at Brandeis University, for example. The first (of many) patents issued two weeks ago.)

Joe's work is terrific and derived independently. I never had interest in its development as a ham mode. If there is interest I will cite the 'polychromatic SETI' reference.

I do want to state how weird it makes me feel to see this idea flower as a 'QSO killer' on ham radio. Or 'QSO ENABLER' . Depends on your point of view, and we are all entitled to different views.

73
Chip W1YW

 

Here is the reference....written with Charleton, who was at Yale at the time.

http://articles.adsabs.harvard.edu/full/seri/ASPC./0074//0000313.000.html

 

Chip,

Especially in this case, nobody is to blame for unintended or unanticipated consequences of technology development.

I would bet that the makers of Twitter had no clue their invention would cause such disruption in politics and mass media journalism either.

My beef is not analog versus digital mode. It's in the appropriate use of each. Your SETI idea followed up by the work of Joe and his gang (now Steve K9AN too) have produced great new tools for hams to use in making QSO's under unusual and marginal propagation conditions.

Essentially "software data amplifiers"; analogous in benefit to SSB vs. AM. Some of the DX capable of being worked with modest means, traditional gear, via these digi modes, is indeed a wonderful breakthrough. I've even popped off a few new grids with it so far, and think these modes may even be shining a new light on how propagation occurs on six meters.

So I can understand a rush to using them for that reason, but the abandonment of more traditional modes for that does not come without a significant if less tangible loss. Two steps forward, one back (?)

Regarding digi modes and spectrum allocation within the 6 meter band - recently I have observed on 50 MHz that some well equipped stations may be running BOTH analog and digital modes simultaneously. scanning and working analog modes between 50.090 - 50.200 to areas where propagation is adequate, while simultaneously monitoring and making (only) weaker signal QSO's up on 50.276 with JT65.

If that's true, that's waaaay COOL! Making a few casual QSO's on SSB/CW while cranking away on JT65 would fill the "snooze time" between JT transmission periods so much more tolerable.

To that end, to configure a station to do essentially simultaneous SO2R on 6m, it would be best if there was MAXIMUM SEPARATION between the two operational sub-bands, to help isolate and prevent receiver overload. So why use some of that expansive spectrum that is allocated and put the digi modes WAY UP the band, like 53.276 MHz?

I imagine the JT channels ended up around 50.276 simply because at the time that seemed like enough separation. Plus, with single transmitter stations being the primary target, and most 6m antennas being Yagi-based and relatively narrow banded, this allowed stations set up and optimized for 50.125 operation to join in.

Further separating analog and digital modes on 6 meters for a good reason would utilize some of that spectrum to help deflect commercial interests in it.

There may be more elegant ways of doing 6m SO2R simultaneous analog-digital, with SDR's, but especially if there were a 3+ MHz separation, I imagine most would require a second antenna, one for each end of the band. Unless there was a nifty high-gain wide-band fractal-based design in the public domain ;-)

73 de John - WØPV

 

I like both digital modes and CW and SSB. I admit, I am surprised at all of the JT65 activity on 6m this season.

From my perspective there are pluses and minuses.
On the plus side:
- more operators are becoming familiar with digital VHF/UHF operations and this is generating side interest in things like digital meteor scatter which expands the spectrum usage.
-Some interesting propagation phenomena are being revealed.
-Maybe some new 6m operators are introduced to a fun band who otherwise thought 6m was always dead.
-possible to make contacts that are very weak or for locations where there is too much noise.
-Easy to leave a receiver on and look through the logs at received signals over time when you are otherwise occupied. Seems like a great boon to beacon like studies.

But on the negative side:
-Less CW and SSB operations as previously mentioned.
-Inefficient use of time. People are making strong signal contacts using slow modes(Defies logic but faster modes will be developed)
-Too many operators jammed in too narrow spectrum when the band is open(Similar problem on SSB and CW existed)
-Rude operating behavior (Non stop calling, Wrong sequence for local or DX, but this also is a problem on SSB and CW but seems worse now)

Things that really surprised me:
You would think it would be much easier to work tougher DX using this mode. Technically it probably is. But logistically not so much. Some rare DX shows up and the big guns still work it or work it again and again burying the weaker tougher paths. Some paths are very short or very weak and a station that is one or two hops closer will usually be orders of magnitude stronger and bury the others. JA to east coast NA openings are a good example of this. Probably EU to west coast has a similar problem.

It is hard to hear weak DX in the presence of strong signals adjacent without a lot of tweaking controls and filters. (Maybe spectrum blocks for this would be better?)

I think the comment that it does not use all the available spectrum is mixed. From a spectral use standpoint JT65 uses about the similar spectrum as CW ~ hundred Hz. So SSB operations use more spectrum and I like them and CW more than JT65. But the biggest problem is that most of the year even less spectrum is used (very little use + beacons) . So if the digital modes expand the useage for these other months that would be a plus. Maybe the novelty will wear off eventually and people will move back to SSB and CW and reserve these weak signal digital modes for the super weak signals that could not be done otherwise.

 

Those who are turned-off of 6m analog operation due to "rude" operators ought to try FM LEO SAT's - now THATS a free-for-all pile-on pile-up!

73, John WØPV

 

I wish people will stop posting 50.276 JT QSOs under SSB on DXWatch

 

Hi Pieter-
When using DxMaps on 6 and 10m, I confirm the zulu time of the plots/paths using a dx cluster because many times the spots on DxMaps are up to one hour old.
Another good site for 6 is :
http://www.on4kst.com/chat/start.php
Click on "50MHz/Region2 chat"
73, Eric n6spp

 

DX Maps has a drop down menu up top "See Only" you can check modes, and only last 15 minutes.

 

W0AAT-
Thanks for the info! I'll give it a look.
73, Eric