EME Moon Bounce on 40 meters?

The thing he is pointing out is that the path loss is just too high for the amount of gain and power possible on 7MHz, for a ham. It is impossible from a physics standpoint, at that power level, and given antennas that hams are likely to be using. It is not impossible at 1000 times the ERP that a typical ham station could run.

So, if you take EME off the table, you look at other possibilities. Some have been mentioned, and linked to.

Joe

 

If all involved heard signals as 59, then it could NOT have been EME. Do a link budget! I accept that you heard a delayed echo. I've experienced that myself. I also copied the HAARP EME, and they needed a helluva lot of power and gain.

 

This is from W1YW's post: "If it was not man made (prank) then it was plasma ducting. the phenom is produced analogously with metamaterials in the lab."

I would like an explanation of how it could be a prank and who the prankster(s) might be. And what does it mean that the phenomenon of plasma ducting "is produced analogously with metamaterials in the lab"?

I'm sure Cecil will chime in here shortly.

 

since the thread has devolved anyways, I thought I would point out to the "Chief Editor, QRZ.COM"

and

echo's and "echos" -> echoes

 

Grammar and Spelling Police (GASP)

It should be "devolved anyway."

 

There is as much chance that this is moonbounce as the chances that this is uranusbounce. ZERO.
As was correctly pointed out, it would take an incredible amount of power and an enormous antenna array to do this

LDEs are unexplained mysteries, but they certainly do happen.

There is always the chance that someone (or a couple of people) with too much time on their hands are doing this a as gag. But my bet is on an LDE.

 

It doesn't take a rocket scientist to figure that one out.

Two kids with some kind of audio link between their ham stations. Only one is transmitting.

Actually, one person could do it. Figure it out. I'm not going to give anyone ideas.

 

Thanks Mike.

It would be a damn shame if the real phenomena became impossible because of the ease of spoofs.

I have no doubt these OM's heard LDE's this weekend. But it was not moonbounce.

I heard several 'DE's this weekend and they were unusual. They occurred on 17M and 30M CW. There were reverberations to in excess of 300miliseconds with discrete 30 dB short-term enhancements that sounded like (but presumably were not)sporadic E pings. Made it very hard to copy and in fact . I also heard some discrete pings of my transmissions. I used omni antennas.

One of the reasons LDE's are heard rarely, BTW, is that we use unidirectional antennas for the most part. This suppresses the received gain of the path. IOW, the echoes are often LP when we are pointed SP. Good luck changing that!

I listen all the time for such phenomena. In November such DE's were prominent on K3RA's CW from this location, for example, which I recorded.

These DE's are caused by ducting, turning the ionopshere into a 'whispering gallery'. I will let the OM's do the math to figure out the number of 'orbits'.

I am very dubious of reports of Doppler on HF LDE's. It is not physically possible. The confusion may arise from audio because there is a misnomer for phasing and flanging effects that is called 'Doppler'. Certainly there are multipath phasing effects that occur. But they are not Doppler, which invokes a differential velocity between transmitter (or its reflection) and receiver.

As I have stated, 40M moonbounce is impossible with radio amateur equipment.

I am very disappointed that anyone chose to take my comments in the negative, or a personal diss. I am merely helping with some facts. I have been interested in LDE's since I was 13, and published an article called "A LONG DELAY ECHO REVISITED" in 1978 in QST, as a grad student.

I am fascinated to hear what others are seeing with DE's and LDE's. Or seeing and hearing


73,
Chip W1YW

 

I want to congratulate you on experiencing this LDE phenomenon. More hams have then will admit it.

Unfortunately your explanation is not tenable, as the path loss to the moon, and HF ionopsheric absorption and reflection preclude this as an acceptable explanation.

Ducting effects can indeed produce discrete pings of reflection with substantial delay. As I mentioned in an above post, I heard 'delayed echoes' of shorter duration (up to 300ms) on my transmissions, and both reverberation and echoes on several other stations on 17M and 30M--this weekend.

What you heard was exciting and unusual. But not moonbounce.

73,
Chip W1YW

 

BTW,

My memory was indeed fuzzy: The actual path loss to the moon and back is of order 280 dB. Hence EME with ham equipment on 40M is impossible.

73,
Chip W1YW

 

This thread was delayed for 11 days due to multiple EME's.

 

ATTN KA8ERS:

Some other helpful info--- the moon was about 380,000 km away on 11 April. It hits perigee in a few days from now. That distance gives a 2W time delay of 2.53 seconds--unfortunately that's not "just shy of 3 seconds", as you describe in your bio listing. Your 'reflector', if this is a non-ducting reflection-- is about 450,000 km away. The moon's greatest distance is about 407,000 km.

BTW guys, I can measure your delay to about a millisec with the audio stuff I have in the lab. Let me know if you'd like some help.

73,
Chip W1YW

 

How's that paper coming along, the one you were going to publish in a ham magazine? Something about fractal antennas?

 

In the Wiki article, EME is mentioned as an explanation just before aliens

Link to Holm article.

 

All this talk about pranks and such...maybe a LDAF (Long-Delayed April Fool)?? Hi...Hi!! (Sorry, guys...couldn't resist!)
Very 73...Joe