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Author Topic: Morse Code QSO  (Read 3520 times)

Luigi

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Morse Code QSO
« on: April 19, 2014, 11:08:54 PM »
I have been working with someone over the phone to train me in CW. My mentor is 375 km from me. We work on 40 meters because of the distance. Anyway, I an using a magnetic loop antenna, and my wattage is a as low as I can go on my radio (5 watts). He it using a possible beam antenna and running at a much higher wattage.

He could hear me very clearly as tapped out cw. I could not hear him at all until he pushed his power up to 400 watts. By then I could barely make him out above the noise level.
I think he was using a beam antenna with a low takeoff angle. My antenna radiates in both upwards and out towards the horizon when it is vertically aligned. The antenna is very directional in vertical mode. I worked with him before and my antenna was horizontally mounted (null facing up and down) and we both could hear each other. He still had to use high wattage.

I suspect takeoff angle has a lot to do with it. Anyone have a similar situation? For closer contacts I would say that NVIS is a better way to go. I think his signal was overshooting me. Perhaps someone int he middle of the pacific ocean was hearing him. Thoughts?

Luigi

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Re: Morse Code QSO
« Reply #1 on: April 19, 2014, 11:37:37 PM »
To me the situation you describe sounds more like a high noise floor at your QTH. The propagation is there since he's clearly hearing your QRP signal yet you can't hear him unless he runs 80 times as much power into a gain antenna.
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gil

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Re: Morse Code QSO
« Reply #2 on: April 19, 2014, 11:46:50 PM »
Hum... He could be skipping over, but then, even a fraction of power bouncing almost straight up would be sufficient for NVIS. I do NVIS with my PAR end-fed set-up vertically. It doesn't take much... The thing is, magnetic loops are not prone to noise. It's the only antenna I can use with my RockMite 40 if I don't want to listen to music! They have a very narrow bandwidth and greatly attenuate, practically eliminate anything outside of it. Mine is very quiet. Such a disparity of power is pretty weird.. You might want to ask more info on his antenna.. Anyway, QRO people don't know what they're doing, so...  ::)  ;D

Gil.

Luigi

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Re: Morse Code QSO
« Reply #3 on: April 20, 2014, 12:10:06 AM »
All,
Thanks for the information. About the RockMite. Can the Crystal be swapped out to change frequencies or bands?
Luigi

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Re: Morse Code QSO
« Reply #4 on: April 20, 2014, 12:17:00 AM »
Hum... He could be skipping over, but then, even a fraction of power bouncing almost straight up would be sufficient for NVIS. I do NVIS with my PAR end-fed set-up vertically. It doesn't take much... The thing is, magnetic loops are not prone to noise. It's the only antenna I can use with my RockMite 40 if I don't want to listen to music! They have a very narrow bandwidth and greatly attenuate, practically eliminate anything outside of it. Mine is very quiet. Such a disparity of power is pretty weird.. You might want to ask more info on his antenna.. Anyway, QRO people don't know what they're doing, so...  ::) ;D

Gil.

Disclaimer: I know very little about magnetic loops and have absolutely no experience with them so file my advice accordingly.

While it may be true that the mag loop is very narrow bandwidth and will consequently attenuate practically anything outside of it, if it's caused by wide band noise it won't matter much since the noise is already inside the pass band. On the other hand according to antenna theory mag loops shouldn't work but yet they do ;D .
"Those who would give up essential liberty to purchase temporary safety, deserve neither liberty nor safety" - Benjamin Franklin

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Luigi

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Re: Morse Code QSO
« Reply #5 on: April 20, 2014, 12:39:46 AM »
The mag loop has very high q. It will resonate tx and rx on a very small part of the spectrum. It has to be tuned when moving around on the dial. once there the signal is very potent (not a good idea to touch one while it is transmitting). Normally I hoist it up on a mast in the horizontal position. I think my vertical mount may have had something to do with it. Also take off angle of the the guy on the other end
Fun stuff.

gil

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Re: Morse Code QSO
« Reply #6 on: April 20, 2014, 01:46:40 AM »
I have a solution but it involves a live chicken and a hatchet...  :o

Gil.

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Re: Morse Code QSO
« Reply #6 on: April 20, 2014, 01:46:40 AM »