That would be my definition of noise power also. That would not help
explain the numbers produced by FT8.
It's curious that my VFO1 - VFO2 measurement produces numbers very close
to what FT8 reports. I have no information as to why that should be,
only measurements that produce those
Is the definition of "noise floor" being changed for FT8?
WSJT-X (and WSJT before that) defines noise as the integrated value
of noise (noise power) across the 2500 Hz (approximately based on
the receiver filter) receive bandwidth.
73,
... Joe, W4TV
On 2018-12-19 9:57 PM, K4SAV wrote:
Joe, thanks for the information. I am not exactly sure what all that
means. My conclusions were based on observed data. It seems pretty
obvious to me that a signal that is more than 50 dB above the noise
floor should not receive a S/N number of -1 dB, which is what FT8
gives. I don't know
On 2018-12-19 4:28 PM, K4SAV wrote:
> The official documentation for FT8 says it will decode signals 24 dB
> below the noise floor. That is not a correct statement most of the
> time.
No, that is a correct statement. Signal reports in WSJT-X for FT8, JT65
and JT9 are *all* measured *with
While sitting around being bored and recovering from a gall bladder
operation, I decided to do some experiments with FT8. First thing I did
was upgrade the software to WSJT-X v2.0.
I hope this post doesn't turn into another FT8 bashing session. My only
goal was to understand how this mode
ALL my antennas have Ohmite OX or OY resistors from the antenna to ground.
>From 56k to a megohm or three. Doesn't everybody? :-)
Ditto at dipole feedpoints.
73, Mike
www.w0btu.com
On Wed, Dec 19, 2018, 12:19 PM Jamie WW3S wrote:
> Since verticals are know to be "noisy" on receive, and a fix
thanks, makes sense.thats why I asked
- Original Message -
From: "Chuck Dietz"
To: "Jamie WW3S"
Cc: "Topband"
Sent: Wednesday, December 19, 2018 1:29:40 PM
Subject: Re: Topband: choke/bleeder resistor on RXvertical?
The choke bleeds off static charges that accumulate on
At least for the Hi-Z verticals - you can measure a DC voltage when they
are active on the antenna against ground. You would not want to short that
to ground with a choke!!
By having a voltage there - I think you can assume any static DC charges
will be quickly dealt with. Essentially a
The choke bleeds off static charges that accumulate on the vertical. While
I have witnessed noise from huge static charging to a 32 foot vertical
mounted on the roof of the engineering building at Texas Tech in West
Texas, the choke does not bleed off “noise”. Noise is radio frequency
emissions
Since verticals are know to be "noisy" on receive, and a fix is a rf choke or
bleeder resistor to ground, anyone try that on short verticals used for receive
only to quiet some noise?
_
Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
If your inverted L is any good at all it will suck as a receiving
antenna. This is one of the key things to accept about medium wave
but many casual 160 m. operators can't wrap their heads around it. A
flame throwing tx antenna will probably have a completely unacceptable
noise level on
OK,
I ran the random wire, It was a convenient length, from the eve of the
house just outside the shack with a like ten foot length of RG-58 from
the tuner, and out with the wire to a tree almost due south 75 feet away.
No ground system, wire connected to center conductor of the coax. braid
Greetings - I thought I would share a few comments from the recently
concluded visit with friends at the Ethiopian Amateur Radio Society
and our ET3YOTA (Youth On The Air) celebration. It’s been awhile
since I’ve been back here, so it was good to reconnect with everyone.
Bob, W9XY, and I traveled
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