Re: receiver overload

K9HZ <bill@...>
 

Here: https://www.arraysolutions.com/antennas/static-bleed-inductor



Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ

Owner - Operator
Big Signal Ranch – K9ZC
Staunton, Illinois

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Soufriere, St. Lucia W.I.
Rent it: www.VillaGrandPiton.com
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Moderator – North American QRO Group at Groups.IO.

email: @Doc_Bill

-----Original Message-----
From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Tim Gorman
Sent: Saturday, April 21, 2018 11:25 AM
To: BITX20@groups.io
Subject: Re: [BITX20] receiver overload

Noise from static buildup varies with the weather and wind. If you think you have static buildup then all you have to do is disconnect your antenna, use a jumper cable to short each element to ground, and then reconnect the antenna. If your noise level drops significantly then you had static buildup. If not, then you are hearing atmospheric noise and/or phase noise in the receiver. The two can be differentiated by just disconnecting the antenna to see what kind of noise drop you see.

Noise from static buildup is typically not static. It does not sound like the white noise, more like a buzzing or popping, and sometimes even like a musical tone.

A tuner, even one that is isolated by a capacitor from the antenna, typically won't "tune" static buildup noise. The noise is basically from small discharges caused by charge equalization. Can you use your tuner to to "tune-in" or "tune-out" the noise from the static discharge of a lightning strike? Mine won't. The "noise" from the lightning strike comes through no matter where the tuner is set.

If noise in the receiver goes up and down as you operate your tuner to find the best match between your receiver and your antenna it's because it is actually working. It is highly unlikely that the noise you hear going up and down is from static buildup on the antenna.

tim ab0wr

On Fri, 20 Apr 2018 20:21:25 -0500
"K9HZ" <@Doc_Bill> wrote:

I guess that then assumes you have a very simple tuner (Cap-L leg)?
No impedance transformers, inductors to ground, etc.


Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ
PJ2/K9HZ

Owner - Operator
Big Signal Ranch – K9ZC
Staunton, Illinois

Owner – Operator
Villa Grand Piton – J68HZ
Soufriere, St. Lucia W.I.
Rent it: www.VillaGrandPiton.com
Like us on Facebook!

Moderator – North American QRO Group at Groups.IO.

email: @Doc_Bill



-----Original Message-----
From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Tim
Gorman Sent: Friday, April 20, 2018 8:18 PM
To: BITX20@groups.io
Subject: Re: [BITX20] receiver overload

I agree! But if the problem here is static buildup then a tuner won't
help any more than the coax connector on the rig!

tim ab0wr

On Fri, 20 Apr 2018 17:37:45 -0500
"K9HZ" <@Doc_Bill> wrote:

That is not where you want static charges dissipating! Chokes to
ground, resistors, at the antenna. All a better place for it (the
fire) to happen.


Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ
PJ2/K9HZ

Owner - Operator
Big Signal Ranch – K9ZC
Staunton, Illinois

Owner – Operator
Villa Grand Piton – J68HZ
Soufriere, St. Lucia W.I.
Rent it: www.VillaGrandPiton.com
Like us on Facebook!

Moderator – North American QRO Group at Groups.IO.

email: @Doc_Bill



-----Original Message-----
From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Tim
Gorman Sent: Friday, April 20, 2018 4:05 PM
To: BITX20@groups.io
Subject: Re: [BITX20] receiver overload

I'm sure it happens. But not consistently. You need wind and
something to create the charge like blowing dust. If the tuner is
dissipating the charge why doesn't the rig itself do it, at least
with an unbalanced feed?

tim ab0wr

On Fri, 20 Apr 2018 08:47:00 -0500
"K9HZ" <@Doc_Bill> wrote:

Unless the antenna is picking up a static charge and the antenna
tuner is acting like an impedance to ground draining that charge
off. Don't laugh, it happens.


Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ
PJ2/K9HZ

Owner - Operator
Big Signal Ranch – K9ZC
Staunton, Illinois

Owner – Operator
Villa Grand Piton – J68HZ
Soufriere, St. Lucia W.I.
Rent it: www.VillaGrandPiton.com
Like us on Facebook!

Moderator – North American QRO Group at Groups.IO.

email: @Doc_Bill



-----Original Message-----
From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Tim
Gorman Sent: Friday, April 20, 2018 8:42 AM
To: BITX20@groups.io
Subject: Re: [BITX20] receiver overload

Usually a tuner will increase noise, at least atmospheric noise,
as the tuner creates a match between the receiver and the antenna.
A matched antenna shouldn't "tame" the noise. If that is actually
happening then a closer look at the system might be appropriate.

tim ab0wr



On Fri, 20 Apr 2018 11:39:39 +1000 "John Sharpe"
<johsharpe@...> wrote:

Hi all,

I just had a thought about new users of the uBitx and the
Bitx40.

I have both of these fine rigs but with my good antenna - a
ZS6BKW
<http://www.nc4fb.org/wordpress/zs6bkw-multi-band-antenna/> at
30 feet
- the receivers are swamped by noise and big signals on 40
metres.

When I tested just now a 59+ 10 signal on my IC-7300 was
unreadable on the Bitexes with the big antenna (which has a low
SWR at 40 metres) because of noise. With an antenna of just 6
feet of wire in the shack the signal was readable (but weak) on
the Bitexes!

I usually use a tuner beween the antenna and the Bitexes - that
works fine to tame the noise. Also I have fitted an RF control
to the Bitx40 that helps quieten big signals.

But if you have lots of noise in the receiver and no tuner - try
a smaller antenna on receive (it will be no good for
transmitting). If that improves things maybe you need a tuner or
an RF control.

73s John V2VOL



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