I must have missed something, but shouldn't the ferrites be on the antenna
feed line near the antenna and not on the stove?
Mike
K4QET
-----Original Message-----
From: Topband [mailto:topband-bounces@contesting.com] On Behalf Of
topband-request@contesting.com
Sent: Monday, November 07, 2016 12:00 PM
To: topband@contesting.com
Subject: Topband Digest, Vol 167, Issue 4
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Today's Topics:
1. Re: RF interference from 160m to GE Electric stove (Bob K6UJ)
2. Re: RF interference from 160m to GE Electric stove
(JAYB1943@OPTONLINE.NET)
3. Re: RF interference from 160m to GE Electric stove (Gary Smith)
4. Re: RF interference from 160m to GE Electric stove
(Arthur Delibert)
5. Traditional or off-center fed 160m vertical design?
(Robert Fanfant)
6. Re: RF interference from 160m to GE Electric stove (Gary Smith)
7. Re: Traditional or off-center fed 160m vertical design?
(Herbert Schoenbohm)
8. Re: Traditional or off-center fed 160m vertical design?
(Clive GM3POI)
9. Re: Traditional or off-center fed 160m vertical design?
(David Cutter)
----------------------------------------------------------------------
Message: 1
Date: Sun, 6 Nov 2016 09:17:41 -0800
From: Bob K6UJ <k6uj@pacbell.net>
To: topband@contesting.com
Subject: Re: Topband: RF interference from 160m to GE Electric stove
Message-ID: <11ba6478-737f-2704-af48-265985a84faa@pacbell.net>
Content-Type: text/plain; charset=utf-8; format=flowed
Bob,
I had to chuckle about your experience on triggering all that stuff in
the house. :-)
Although not HF band RF interference but I solved an RFI issue on 2
meters with snap on ferrites also.
When I keyed up my 50 watt 2 meter xcvr it would activate the garage
door opener on the house next door. :-)
I probably could have changed the frequency code on his unit but the
ferrites worked fine. I don't know the mix
just tried a couple of clamp ons I had.
Bob
K6UJ
On 11/6/16 8:20 AM, Bob Lawson N6RW wrote:
Jay
If you use snap-on ferrites, make sure they are #31 mix. 31 mix is
substantially better than others (like 47 mix) at 160m. When I had a
vertical on the roof at my So Cal house, I would reset my DirecTV HD
receivers, trigger my home security alarm, turn off my air
conditioning fan and so on, when I transmitted on 80 meters. All
problems were solved with 31 mix ferrites.
73 de Bob N6RW
On 11/6/2016 8:58 AM, Lloyd - N9LB wrote:
Hello Jay!
Have you tried putting a string of "RF Suppression Snap-On Ferrites"
on the power cord?
Are the dimensions of the cord such that it is possible to use "RF
Suppression Snap-On Ferrites"? The largest I could find are .75"
inside diameter.
https://www.dxengineering.com/search/part-type/rf-suppression-snap-on-ferrit
e-beads
If the power cord for the electric stove is too large, perhaps the
Snap-On Ferrites could be added to the Romex cable feeding the stove
outlet if the wiring is accessible, such as in an unfinished basement.
73
Lloyd - N9LB
-----Original Message-----
From: Topband [mailto:topband-bounces@contesting.com] On Behalf Of
JAYB1943@OPTONLINE.NET
Sent: Sunday, November 06, 2016 9:34 AM
To: topband@contesting.com
Subject: Topband: RF interference from 160m to GE Electric stove
Hi guys ? I have recently added a 160m amp to my station and have
created an RFI problem I can?t solve.
When I transmit on 160 with any more than 150 watts, the GE electric
stove in the kitchen ALARMS and must be reset. I guess the 160 signal
from the vertical is getting into the AC power lines (just a few feet
away from the AC feed off the pole) and then into the electronics
into the stove. Reducing the output power to 125 watts or so does not
cause the problem. Not a permanent condition; hitting the stop button
on the stove controls stops the stove alarm but starts again when I
transmit. My XYL HATES alarms?she is a retired ICU RN and I think she
got conditioned to panic when ANY alarm goes off !
Anyhow I wondered if anybody has any similar experience with problems
like this on 160 and how to solve them. I am tempted to just have an
electrician come in and install a BIG RF filter on the AC line ?
either just on the Stove line or to the main feed but I fear this is
a lot of $$$. I am hesitant to do this one on my own for insurance
reasons if nothing else.
Any ideas ?
Thanx ? Jay NY2NY
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Message: 2
Date: Sun, 6 Nov 2016 12:33:24 -0500
From: <JAYB1943@OPTONLINE.NET>
To: <topband@contesting.com>
Subject: Re: Topband: RF interference from 160m to GE Electric stove
Message-ID: <FC564F3D4E3145929473C04B81DD4926@jayPC>
Content-Type: text/plain; charset="utf-8"
Thanks to all the guys who answered my query ? seems unanimous that I should
add Mix 31 Ferrites to the stove ac feed so just ordered them from DX
engineering ? shud be installed and tested by the end of the week..
Will probably also add some .05 or so bypass caps to the line while I?m
there ? wouldn?t hurt !
tnx again ? keep y?all posted..Jay NY2NY
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Message: 3
Date: Sun, 06 Nov 2016 13:36:41 -0500
From: "Gary Smith" <Gary@ka1j.com>
To: Topband@contesting.com
Subject: Re: Topband: RF interference from 160m to GE Electric stove
Message-ID: <581F7839.26623.1E06AE0@Gary.ka1j.com>
Content-Type: text/plain; charset=ISO-8859-1
Another thing that might help if the
ferrites don't do the job is to run a wire
from a series variable capacitor and
variable/tapped inductor, to the stove or
possibly to the metal conduit the wires to
the stove are going through. This, with an
attachment to a counterpoise or ground.
My father had problems when he would
transmit on 80 and it would trigger the
system that used house wiring to turn on
various lights in the house when a phone
call came in on her line, or the door bell
was rung. She was totally deaf and needed
this to get to her TTY setup for a voice
operator to come in and translate speech
to her printout.
He did as I described and had a RF ammeter
in line. When the capacitor/inductor was
adjusted under a key down situation, you
could follow the result on the ammeter and
at the right setting, the interference
stopped triggering the in-line receivers.
Sometimes he needed to tweak the setting
but it always worked for him.
I think MFJ used to have something to do
just this, I don't recall what they called
it.
Good luck & 73,
Gary
KA1J
Thanks to all the guys who answered my query - seems unanimous that
I should add Mix 31 Ferrites to the stove ac feed so just ordered them
from DX engineering - shud be installed and tested by the end of the
week.. Will probably also add some .05 or so bypass caps to the line
while I?m there - wouldn?t hurt !
tnx again - keep y?all posted..Jay NY2NY
---
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------------------------------
Message: 4
Date: Sun, 6 Nov 2016 19:12:14 +0000
From: Arthur Delibert <radio75a3@msn.com>
To: "Topband@contesting.com" <Topband@contesting.com>, "Gary@ka1j.com"
<Gary@ka1j.com>
Subject: Re: Topband: RF interference from 160m to GE Electric stove
Message-ID:
<BN6PR18MB1314E6E12F4A79C3C92E1253E4A40@BN6PR18MB1314.namprd18.prod.outlook.
com>
Content-Type: text/plain; charset="iso-8859-1"
The product that does this is the MFJ Artificial Ground. Costs about $160.
Good luck.
Art Delibert, KB3FJO
________________________________
From: Topband <topband-bounces@contesting.com> on behalf of Gary Smith
<Gary@ka1j.com>
Sent: Sunday, November 6, 2016 1:36 PM
To: Topband@contesting.com
Subject: Re: Topband: RF interference from 160m to GE Electric stove
Another thing that might help if the
ferrites don't do the job is to run a wire
from a series variable capacitor and
variable/tapped inductor, to the stove or
possibly to the metal conduit the wires to
the stove are going through. This, with an
attachment to a counterpoise or ground.
My father had problems when he would
transmit on 80 and it would trigger the
system that used house wiring to turn on
various lights in the house when a phone
call came in on her line, or the door bell
was rung. She was totally deaf and needed
this to get to her TTY setup for a voice
operator to come in and translate speech
to her printout.
He did as I described and had a RF ammeter
in line. When the capacitor/inductor was
adjusted under a key down situation, you
could follow the result on the ammeter and
at the right setting, the interference
stopped triggering the in-line receivers.
Sometimes he needed to tweak the setting
but it always worked for him.
I think MFJ used to have something to do
just this, I don't recall what they called
it.
Good luck & 73,
Gary
KA1J
Thanks to all the guys who answered my query - seems unanimous that
I should add Mix 31 Ferrites to the stove ac feed so just ordered them
from DX engineering - shud be installed and tested by the end of the
week.. Will probably also add some .05 or so bypass caps to the line
while I?m there - wouldn?t hurt !
tnx again - keep y?all posted..Jay NY2NY
---
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Message: 5
Date: Sun, 6 Nov 2016 19:16:45 +0000
From: Robert Fanfant <rfanfant@hotmail.com>
To: "topband@contesting.com" <topband@contesting.com>
Subject: Topband: Traditional or off-center fed 160m vertical design?
Message-ID:
<BY2PR10MB063143FAB2401EF73A33EF4FC9A40@BY2PR10MB0631.namprd10.prod.outlook.
com>
Content-Type: text/plain; charset="utf-8"
I am planning on putting up a 160m T vertical next week. After doing some
modeling , I would like your thoughts concerning using a traditional ?
vertical design, versus an off center fed design.
My modeling of the traditional designs approaches 36-38 ohms of real
impedance while the off center fed design shows I can obtain close to 50
ohms of real impedance.
Details:
Trees on my property are roughly 143? tall and I can?t use ground mounted
radials for a variety of reasons. I found I can get up to 110? feet of
usable vertical length, assuming radials @ 20? off the ground. The antenna
will be suspended between trees.
I?ve discovered through modeling using elevated radials at 20? , a 110
vertical section. By varying both the radial and T top section lengths , I
can design a 160m vertical which approaches 50 ohms of real impedance ,
using an off center fed design. It exhibits excellent characteristics from
what the modeling shows. Based on the modeling I?m leaning towards the off
center fed design primarily because It has a lower SWR at resonance
(1.83Mhz) than the traditional vertical, and removes the need for
building/adding a matching network if I only want to cover the lower
portion of the band (CW). Thoughts?
-rob N7QT
Sent from Mail<https://go.microsoft.com/fwlink/?LinkId=550986> for Windows
10
------------------------------
Message: 6
Date: Sun, 06 Nov 2016 14:17:54 -0500
From: "Gary Smith" <Gary@ka1j.com>
To: Topband@contesting.com
Subject: Re: Topband: RF interference from 160m to GE Electric stove
Message-ID: <581F81E2.23134.2062812@Gary.ka1j.com>
Content-Type: text/plain; charset=ISO-8859-1
I thought I should add some photos of what
he made. His was a bit more complex with a
transformer and bridge rectifier. Mine was
more basic & I used a roller inductor but
it did the job.
I didn't shrink the photos so as to leave
more detail available when you click on a
photo.
http://doctorgary.net/RFI-1.jpg
http://doctorgary.net/RFI-2.jpg
http://doctorgary.net/RFI-3.jpg
http://doctorgary.net/RFI-4.jpg
http://doctorgary.net/RFI-5.jpg
73,
Gary
KA1J
Another thing that might help if the
ferrites don't do the job is to run a wire
from a series variable capacitor and
variable/tapped inductor, to the stove or
possibly to the metal conduit the wires to
the stove are going through. This, with an
attachment to a counterpoise or ground.
My father had problems when he would
transmit on 80 and it would trigger the
system that used house wiring to turn on
various lights in the house when a phone
call came in on her line, or the door bell
was rung. She was totally deaf and needed
this to get to her TTY setup for a voice
operator to come in and translate speech
to her printout.
He did as I described and had a RF ammeter
in line. When the capacitor/inductor was
adjusted under a key down situation, you
could follow the result on the ammeter and
at the right setting, the interference
stopped triggering the in-line receivers.
Sometimes he needed to tweak the setting
but it always worked for him.
I think MFJ used to have something to do
just this, I don't recall what they called
it.
Good luck & 73,
Gary
KA1J
Thanks to all the guys who answered my query - seems unanimous that
I should add Mix 31 Ferrites to the stove ac feed so just ordered
them from DX engineering - shud be installed and tested by the end
of the week.. Will probably also add some .05 or so bypass caps to
the line while I?m there - wouldn?t hurt !
tnx again - keep y?all posted..Jay NY2NY
---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus _________________ Topband Reflector
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_________________
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------------------------------
Message: 7
Date: Sun, 6 Nov 2016 19:09:42 -0400
From: Herbert Schoenbohm <herbs@vitelcom.net>
To: topband@contesting.com
Subject: Re: Topband: Traditional or off-center fed 160m vertical
design?
Message-ID: <4eefc6de-8448-ed7b-8faa-3da479a5b769@vitelcom.net>
Content-Type: text/plain; charset=utf-8; format=flowed
Not having a balanced "T" top section defeats the whole purpose of
reducing the radiation from the top horizontal wire. IMHO the more you
can reduce wasted radiation of the cloud warmer effect the better your
antenna will perform for DX.
Herb, KV4FZ
On 11/6/2016 3:16 PM, Robert Fanfant wrote:
Based on the modeling I?m leaning towards the off center fed design
primarily because It has a lower SWR at resonance (1.83Mhz) than the
traditional vertical, and removes the need for building/adding a matching
network if I only want to cover the lower portion of the band (CW).
Thoughts?
------------------------------
Message: 8
Date: Mon, 7 Nov 2016 00:10:02 -0000
From: "Clive GM3POI" <gm3poi2@btinternet.com>
To: <topband@contesting.com>
Subject: Re: Topband: Traditional or off-center fed 160m vertical
design?
Message-ID: <000001d2388b$49608e80$dc21ab80$@btinternet.com>
Content-Type: text/plain; charset="utf-8"
Rob,
An off set top loading will radiate unlike a balanced top loading. Far
better to eliminate Horizontal radiation unless you want to be louder within
a couple of hundred miles. Resonate the vertical at say 1.89, then place a
hairpin coil across the feed point to bring the antenna to 1:1 at the wanted
operating frequency. Your proposed antenna will need a good feed point
choke. 73 Clive GM3POI
-----Original Message-----
From: Topband [mailto:topband-bounces@contesting.com] On Behalf Of Robert
Fanfant
Sent: 06 November 2016 19:17
To: topband@contesting.com
Subject: Topband: Traditional or off-center fed 160m vertical design?
I am planning on putting up a 160m T vertical next week. After doing some
modeling , I would like your thoughts concerning using a traditional ?
vertical design, versus an off center fed design.
My modeling of the traditional designs approaches 36-38 ohms of real
impedance while the off center fed design shows I can obtain close to 50
ohms of real impedance.
Details:
Trees on my property are roughly 143? tall and I can?t use ground mounted
radials for a variety of reasons. I found I can get up to 110? feet of
usable vertical length, assuming radials @ 20? off the ground. The antenna
will be suspended between trees.
I?ve discovered through modeling using elevated radials at 20? , a 110
vertical section. By varying both the radial and T top section lengths , I
can design a 160m vertical which approaches 50 ohms of real impedance ,
using an off center fed design. It exhibits excellent characteristics from
what the modeling shows. Based on the modeling I?m leaning towards the off
center fed design primarily because It has a lower SWR at resonance
(1.83Mhz) than the traditional vertical, and removes the need for
building/adding a matching network if I only want to cover the lower
portion of the band (CW). Thoughts?
-rob N7QT
Sent from Mail<https://go.microsoft.com/fwlink/?LinkId=550986> for Windows
10
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------------------------------
Message: 9
Date: Mon, 7 Nov 2016 14:23:13 -0000
From: "David Cutter" <d.cutter@ntlworld.com>
To: "Robert Fanfant" <rfanfant@hotmail.com>, <topband@contesting.com>
Subject: Re: Topband: Traditional or off-center fed 160m vertical
design?
Message-ID: <A93E401FA443426DB4730276BB31403D@DavidPC>
Content-Type: text/plain; format=flowed; charset="UTF-8";
reply-type=original
Have a look at this idea:
http://www.m0rzf.co.uk/ants1/
This is an off centre fed but your normal feeder is connected to the end of
the antenna via a choke. I've made several of the 40m version and 3 using
double the sizes for 80m. I used simpler chokes for both and measured
common mode currents to ensure it worked as an inverted L with no ground
radials. This is a variant of the sleeve dipole or "end fed dipole" often
used at VHF and above.
I and a friend are now making one for 160m but with a different choke and
balun suitable for the band. The Ruthroff will be about twice as long and
the choke will be on #31 core.
Give it some thought; it seems to me you have the facility (height) to make
a good one, whereas we are very much restricted in height.
My keenness for this idea is that radiation to the ground is minimised
because the real feedpoint is several metres in the air at the junction
with the Ruthroff. In my case I've arranged the transmitter attachment (end
connection) to be at ground level where the choke is grounded to minimise
common mode current back to the tx.
In my tests on the 80m version, I can reasonably estimate losses at about
5%, most of which is in the choke (a #43 with 16 turns of thin PTFE coax).
I used air tests with several precision thermistors and in pure water as a
calorimeter test running 100W. With suitable rating core and coax I don't
see why it shouldn't run at your legal limit.
David
G3UNA
----- Original Message -----
From: "Robert Fanfant" <rfanfant@hotmail.com>
To: <topband@contesting.com>
Sent: Sunday, November 06, 2016 7:16 PM
Subject: Topband: Traditional or off-center fed 160m vertical design?
I am planning on putting up a 160m T vertical next week. After doing some
modeling , I would like your thoughts concerning using a traditional ?
vertical design, versus an off center fed design.
My modeling of the traditional designs approaches 36-38 ohms of real
impedance while the off center fed design shows I can obtain close to 50
ohms of real impedance.
Details:
Trees on my property are roughly 143? tall and I can?t use ground
mounted radials for a variety of reasons. I found I can get up to 110?
feet of usable vertical length, assuming radials @ 20? off the ground.
The antenna will be suspended between trees.
I?ve discovered through modeling using elevated radials at 20? , a 110
vertical section. By varying both the radial and T top section lengths ,
I can design a 160m vertical which approaches 50 ohms of real impedance ,
using an off center fed design. It exhibits excellent characteristics from
what the modeling shows. Based on the modeling I?m leaning towards the off
center fed design primarily because It has a lower SWR at resonance
(1.83Mhz) than the traditional vertical, and removes the need for
building/adding a matching network if I only want to cover the lower
portion of the band (CW). Thoughts?
-rob N7QT
Sent from Mail<https://go.microsoft.com/fwlink/?LinkId=550986> for Windows
10
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------------------------------
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