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 can't hear stations who can hear me clearly - angle rad? 
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Post can't hear stations who can hear me clearly - angle rad?
Hello Folks,
Id like your collective oponion on this one...
I reciently installed a linear in my shack which works very well (AL-80A).... infact too well it seems.

I am now reglarly informed (by other stations) that distant stations are calling me but i jusy can't hear anything.

I began to think perhaps my antenna could be to blame if it has a very high angle of take off.
The antenna is an 20m inverted Vee wire dipole with apex at 35 ft up and 30deg drops each side.

The thought also crossed my mind that perhaps this is a common thing when running a linear... when the distant station may be barefoot.
But even when I contact stations who are also running power (some at 1kw+) I still find they give me far better signal reports that i can honestly give them and were not just talking the usual "59".. time and time again I get far better reports from DX than i can possibly give... so Ive discounted this as the problem and returned to thinking about my antenna.

infact just today I was called by a VK who I could bearly hear, and he said i was 57 in the clear!!!

one other possibility... I live in a fairly built up area with many houses and 40kv power lines at about 200ft away.
I do see noise humps spaced at ~56 Khz intervals all across the HF band, these sit at S5 whereas inbetween the humps the grass is at S2 (rig is IC7600, preamp off).
I have started to look for a noise cancelation device like the MFJ 1026 to see if this is the cause of my aparent deafness.

so anyway...
I also want to try different antennas:
Option 1. A dedicated 20m delta loop, top fed in vertical mode, its max height would be 35 ft.
Option 2. A 1/4 vertical with ground plane, its base at 30ft, 3 ground radials at 30 degrees drop

which of the above has a chance to out perform existing inverted Vee dipole???
I'm thinking the 1/4 gp might be better but I'd like to hear other oponions.

appriciate your thoughts guys

Thanks
Ray


Fri Feb 24, 2017 10:15 pm
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 can't hear stations who can hear me clearly - angle rad? 
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Post Re: can't hear stations who can hear me clearly - angle rad?
I think you have answered your own question...,


Fri Feb 24, 2017 10:44 pm
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 can't hear stations who can hear me clearly - angle rad? 
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Post Re: can't hear stations who can hear me clearly - angle rad?
"Outperform" is interesting...its going to depend on so many things. You should have both. I ave a doublet and a vertical...some days ones better, some days tother way round. Just depends on where im listening to.

Simple answer is...try them and see.

As for tje VK...remember his noise floor is likely way way lower than yours...

Good luck

D

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Fri Feb 24, 2017 10:56 pm
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 can't hear stations who can hear me clearly - angle rad? 
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Post Re: can't hear stations who can hear me clearly - angle rad?
Having used a vertical on the higher bands, you may be disappointed with a vertical except for 10m probably.
These other stations you struggle to hear may be using beams which will give them an advantage both ways.
I use an mfj 1026 here and while its fiddley to set it is quite effective.
My antennas btw are a cobweb and a g7fek, only run 100 watts and havent heard anything I cant work although I am predominantly using CW.
experiments is the key, try a loop and try moving the feed point to see what works best.
so many variables and what works here may not work for you.
Anyhow good luck with trying things out.

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Fri Feb 24, 2017 11:47 pm
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 can't hear stations who can hear me clearly - angle rad? 
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Post Re: can't hear stations who can hear me clearly - angle rad?
Thanks for the comments guys , interesting reading.

I did once have a vertical on 10m , a few years ago when conditions were better.
It worked fine but the noise/grass level was higher than a dipole, I suspect this is normal with vertical antennas.

The delta loop in theory should have a low angle of radiation, but I read conflicting reports on performance.

Like someone just said, I will experiment with both .

I might also try a rotatable dipole, perhaps I can null out the noise source!


Sat Feb 25, 2017 7:44 am
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 can't hear stations who can hear me clearly - angle rad? 
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Post Re: can't hear stations who can hear me clearly - angle rad?
You're now what's known as an "Alligator" :P

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Sat Feb 25, 2017 9:01 am
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 can't hear stations who can hear me clearly - angle rad? 
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Post Re: can't hear stations who can hear me clearly - angle rad?
If you want to null a noise youll need a balanced aerial or . Loop.

Alternatively have a look at amplified receiving loops. Theres a very good kit by an LZ...google LZ1 receiving loops. I have one and its quiye useful

D

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Sat Feb 25, 2017 9:02 am
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 can't hear stations who can hear me clearly - angle rad? 
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Post Re: can't hear stations who can hear me clearly - angle rad?
ei9ju wrote:
You're now what's known as an "Alligator" :P


What's that about life is too short for QRP?

If everyone used a kilowatt then the bands would be a lot more active, bit like a big contest weekend, all those big signals and everyone able to clearly hear the DX station and him taking the time to talk to every single S9+30 station he can fear shouting at him. :blackeye:

Cheese, Dave.


Sat Feb 25, 2017 2:43 pm
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 can't hear stations who can hear me clearly - angle rad? 
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Post Re: can't hear stations who can hear me clearly - angle rad?
G7VQE wrote:
ei9ju wrote:
You're now what's known as an "Alligator" :P


What's that about life is too short for QRP?

If everyone used a kilowatt then the bands would be a lot more active, bit like a big contest weekend, all those big signals and everyone able to clearly hear the DX station and him taking the time to talk to every single S9+30 station he can fear shouting at him. :blackeye:

Cheese, Dave.


I do have to admit that since getting the Linear my success rate for DX contacts has shot up!
Life was harder with the 100w and a dipole, QSO's were short and sporadic... now I can have long QSO's with virtually any contact while still on the dipole.


Sat Feb 25, 2017 5:13 pm
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 can't hear stations who can hear me clearly - angle rad? 
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Post Re: can't hear stations who can hear me clearly - angle rad?
I've ordered a noise canceller from Poland... I'll give that a go before anything else.

Thanks for the input lads.

73
Ray


Sun Feb 26, 2017 9:22 am
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 can't hear stations who can hear me clearly - angle rad? 
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Post Re: can't hear stations who can hear me clearly - angle rad?
I used to have the same problem as yourself and mainly it is due to the local noise floor which gets progressively worse on the lower bands. What I thought was normal wasnt really that normal at all and signals were lost in the noise all the time. To solve it over xmas I built a battery powered remote rx that I could drop off when required. I have a selection of antennas in a tree out of sight in a field about 400m from the house away from the houses. This links back to the shack using a wireless bridge and I run SDR-Radio software to connect it all together and bring the recieved audio into the shack. It cost me a few quid and a lot of experiments but it works perhaps too well now I can hear stations who struggle to hear me even with 400w. On the up side a lot lf new DX in the log and I don't really struggle to copy stations now even the QRP'ers.


Sun Feb 26, 2017 10:40 am
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 can't hear stations who can hear me clearly - angle rad? 
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Post Re: can't hear stations who can hear me clearly - angle rad?
Intresting solution!

I was considering a WebSDR version of that, but most of the WebSDR have fairly poor antennas.

If all else fails I will consider it.

Cheers

Ray


Mon Feb 27, 2017 8:11 pm
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 can't hear stations who can hear me clearly - angle rad? 
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Post Re: can't hear stations who can hear me clearly - angle rad?
Drop me a PM if you want more info you will know if it suits your neighbourhood or not. Friendly farmer within line of sight is a good starting point. I tried the MFJ1025 and Wellbrook loops both work well but need tweaking as local noise seems a constant battle. I also looked at the online SDR's but none are really that local, dont cover CW on bands of interest or as you say have poor antennas.


Mon Feb 27, 2017 11:44 pm
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 can't hear stations who can hear me clearly - angle rad? 
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Post Re: can't hear stations who can hear me clearly - angle rad?
so by way of update.... here is the latest on this issue.... you might find it interesting.

I purchased an X Phase noise eliminator ( many kits out there) from a Polish maker.
it's based on an open source design and works very well indeed... at 50quid it's a good purchase.

I have dual band dipole as my main antenna (20m and 17m) made up of two dipoles with a common feed point, both running in same direction.

My 'noise rx' antenna is another dipole, roughly resonant on 15m due to space limitations, but receives well enough to feed the X phase noise eliminator.

So here is the interesting part.. on some stations the combination of Rx and Main antenna actually increase the signal level whilst reducing the noise !!!
I asked myself how can this be?... and it turns out that the RX and main antennas run in different directions, thus have different null directions.
the increase can be as much as 5 S-points.

So not only does the noise eliminator allow noise to be cancelled, it also allows two dipoles to be phased mixed, enhancing the gain characterises of a horizontal dipole into an omnidirectional... this was totally unexpected and a delightful discovery.

So even if you don't have local noise, any horizontal dipole can benefit from being mixed with another dipole at a different angle.

Especially useful if you don't have a rotary dipole (like me).
The downside is that it only works on RX.

73
Ray
EI3GD


Fri Mar 10, 2017 1:05 pm
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 can't hear stations who can hear me clearly - angle rad? 
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Post Re: can't hear stations who can hear me clearly - angle rad?
Glad its working. Which unit did you buy?
d

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Fri Mar 10, 2017 2:08 pm
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