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I tried to see what my SWR and Smith Chart on my rubber duck antenna for FT-70D and got VERY high SWR readings...is it because it is a dual antenna for 70cm as well as 2m?


Walter Egenmaier 2022/01/10 09:54

I tried to see what my SWR and Smith Chart on my rubber duck antenna for FT-70D and got VERY high SWR readings...is it because it is a dual antenna for 70cm as well as 2m?
Or do you think it is damaged internally. People hear me ok on the rubber duck antenna.
Walt

Jim Lux 2022/01/10 10:02

On 1/10/22 9:54 AM, Walter Egenmaier wrote:
> I tried to see what my SWR and Smith Chart on my rubber duck antenna
> for FT-70D and got VERY high SWR readings...is it because it is a dual
> antenna for 70cm as well as 2m?
> Or do you think it is damaged internally. People hear me ok on the
> rubber duck antenna.
> Walt
> _


I remember when I took the rubber duck from my TH-F6A (triband, 2m, 220,
440) and hooked it up to the VNA at work.

Their match is "ok-ish" but remember, it's also a monopole, and the
other half of the antenna is you.  Someone did some experiments with a
test fixture they'd hold in their hand, with chokes and coax running
down their arm to the VNA.

The other thing is that they will develop an intermittent problem -The
inside is basically a spring embedded in the plastic, and that spring
can get a small crack in it, so in some orientations it's open, in
others it's closed, in yet others, it's partial. And because of the
construction, there's hysteresis. The spring shifts and slides in the
plastic.

Walter Egenmaier 2022/01/10 12:12

Jim, thank you for that explanation.
I was definitely getting variable results with me touching or holding the
antenna, but my SWR was up in the 1 to 8.2 range...way off! Guess I need to
set it down and not touch it at all to get more accurate readings. I think
I might someone else with an FT-70D and see if their rubber duck reads the
same. I will say I had it in the car and it looks a little bent, so I may
have damaged it putting it in the glove compartment when I took it off to
hook up my mobile antenna to it to give it better range while driving.

Now I also have another longer "rubber duck" that worked just fine that is
also for 2m and 70cm.

Thank you and 73's
Walt
WB4ZUT


On Mon, Jan 10, 2022 at 12:02 PM Jim Lux <jim@luxfamily.com> wrote:

> On 1/10/22 9:54 AM, Walter Egenmaier wrote:
> > I tried to see what my SWR and Smith Chart on my rubber duck antenna
> > for FT-70D and got VERY high SWR readings...is it because it is a dual
> > antenna for 70cm as well as 2m?
> > Or do you think it is damaged internally. People hear me ok on the
> > rubber duck antenna.
> > Walt
> > _
>
>
> I remember when I took the rubber duck from my TH-F6A (triband, 2m, 220,
> 440) and hooked it up to the VNA at work.
>
> Their match is "ok-ish" but remember, it's also a monopole, and the
> other half of the antenna is you. Someone did some experiments with a
> test fixture they'd hold in their hand, with chokes and coax running
> down their arm to the VNA.
>
> The other thing is that they will develop an intermittent problem -The
> inside is basically a spring embedded in the plastic, and that spring
> can get a small crack in it, so in some orientations it's open, in
> others it's closed, in yet others, it's partial. And because of the
> construction, there's hysteresis. The spring shifts and slides in the
> plastic.
>
>
>
>
>
>
>
>

--
Walter H. Egenmaier, O.D
EyeCare Consultants
Evansville, IN 47708
(812) 426-2020 Phone
(812) 426-2828 Fax
WB4ZUT
wegenmaier@gmail.com
http://www.eyecare-consultants.net

Jim Lux 2022/01/10 10:21

On 1/10/22 10:12 AM, Walter Egenmaier wrote:
> Jim, thank you for that explanation.
> I was definitely getting variable results with me touching or holding
> the antenna, but my SWR was up in the 1 to 8.2 range...way off! Guess
> I need to set it down and not touch it at all to get more accurate
> readings. I think I might someone else with an FT-70D and see if their
> rubber duck reads the same. I will say I had it in the car and
> it looks a little bent, so I may have damaged it putting it in the
> glove compartment when I took it off to hook up my mobile antenna to
> it to give it better range while driving.
>
> Now I also have another longer "rubber duck" that worked just fine
> that is also for 2m and 70cm.
>
> Thank you and 73's
> Walt
> WB4ZUT
>
I have a pizza pan with an SMA feedthrough connector I use for HT
antenna testing. Sure, it's not like a human holding the HT, but it is
repeatable.  I set it on a cardboard box to get it away from stuff.

Michael Cheponis 2022/01/10 10:30

I prefer to use 1/2 wave ducks (generally, 'sleeve' dipoles) because then
you can measure the antenna without an artificial ground; it also has the
benefit of moving the 'high current' point halfway up the duck, into the
air, a bit more away from one's body when talking directly into the HT.

Folks should take a look at the RF absorption curves at HT frequencies --
144 MHz is not so great. 440 is better. Best is antenna on roof of
vehicle, with you inside.

-Mike K6THZ

p,s. I like WB4ZUT's use of a pizza pan. Now, that old one in the garage I
didn't throw out is going to have a New Life! ;-) Tnx OM.


On Mon, Jan 10, 2022 at 10:22 AM Jim Lux <jim@luxfamily.com> wrote:

Jim Lux 2022/01/10 11:00

On 1/10/22 10:30 AM, Michael Cheponis wrote:
> I prefer to use 1/2 wave ducks (generally, 'sleeve' dipoles) because
> then you can measure the antenna without an artificial ground; it also
> has the benefit of moving the 'high current' point halfway up the
> duck, into the air, a bit more away from one's body when talking
> directly into the HT.
>
> Folks should take a look at the RF absorption curves at HT frequencies
> -- 144 MHz is not so great.  440 is better. Best is antenna on roof of
> vehicle, with you inside.
>
> -Mike K6THZ
>
> p,s. I like WB4ZUT's use of a pizza pan.  Now, that old one in the
> garage I didn't throw out is going to have a New Life!  ;-) Tnx OM.
>
>
I never throw away biggish sheets of metal.  It may not meet with
approval for cookie baking, but as a ground plane, or just something to
stick magnetic stuff to..

de W6RMK

N2MS 2022/01/10 14:50

I use the NanoVNA as an HT and hold it as I would a handi-talkie to get a realistic idea of the swr in actual operation. My dual band rubber duckie has a low swr near 144 or 430 Mhz but the lowest SWR is out of the ham bands.

We have to remember we don't have the transmission line loss when the antenna is attached to the radio as long as the transmitter can deliver power to the antenna.

Mike N2MS

W0LEV 2022/01/10 20:55

Also, remember to cal and measure only the band (not plural) in which you
are interested. That would be 144 through 148 MHz and 430 through 450 MHz
- individuially. If you test with one cal for the whole range, 144 through
450 MHz, you may not have enough points to properly indicate SWR.
Calibrate and do each band separately.

Another problem I've had with rubber ducks and other after-market HT
antennas is tolerance of the center pin. I've had several that simply do
not make contact to the jack due to the low end of tolerance
specifications. To fix it for a while, I jsut coat the center pin with
just a very little bit of solder. Eventually, that will compress and a
repeat may be necessary. Possibly this is yet another problem with "With
Love, From China".

Dave - WØLEV

On Mon, Jan 10, 2022 at 6:02 PM Jim Lux <jim@luxfamily.com> wrote:

> On 1/10/22 9:54 AM, Walter Egenmaier wrote:
> > I tried to see what my SWR and Smith Chart on my rubber duck antenna
> > for FT-70D and got VERY high SWR readings...is it because it is a dual
> > antenna for 70cm as well as 2m?
> > Or do you think it is damaged internally. People hear me ok on the
> > rubber duck antenna.
> > Walt
> > _
>
>
> I remember when I took the rubber duck from my TH-F6A (triband, 2m, 220,
> 440) and hooked it up to the VNA at work.
>
> Their match is "ok-ish" but remember, it's also a monopole, and the
> other half of the antenna is you. Someone did some experiments with a
> test fixture they'd hold in their hand, with chokes and coax running
> down their arm to the VNA.
>
> The other thing is that they will develop an intermittent problem -The
> inside is basically a spring embedded in the plastic, and that spring
> can get a small crack in it, so in some orientations it's open, in
> others it's closed, in yet others, it's partial. And because of the
> construction, there's hysteresis. The spring shifts and slides in the
> plastic.
>
>
>
>
>
>
>
>

--
*Dave - WØLEV*
*Just Let Darwin Work*

Jim Lux 2022/01/10 13:41

On 1/10/22 12:55 PM, W0LEV wrote:
> Also, remember to cal and measure only the band (not plural) in which
> you are interested.  That would be 144 through 148 MHz and 430 through
> 450 MHz - individuially.  If you test with one cal for the whole
> range, 144 through 450 MHz, you may not have enough points to properly
> indicate SWR.  Calibrate and do each band separately.


I'm not so sure about that.. the cal linearly interpolates, so as long
as there's not egregious phase wraps between frequency points, it should
be "reasonably good".

I'd worry more about the transition across the harmonic switching
boundary.  But again, the 2m and 440 bands are well on either side of
the typical 300 MHz switchover.

(cal from, say, 100-500 MHz with 100 points would be 4MHz/point)




>
> Another problem I've had with rubber ducks and other after-market HT
> antennas is tolerance of the center pin.  I've had several that simply
> do not make contact to the jack due to the low end of tolerance
> specifications.  To fix it for a while, I jsut coat the center pin
> with just a very little bit of solder. Eventually, that will compress
> and a repeat may be necessary. Possibly this is yet another problem
> with "With Love, From China".


The stock antenna on the TH-F6A has a problem that there's no good
mechanical support for the antenna, so bending it causes the SMA
connector to move.

Walter Egenmaier 2022/01/10 17:04

I'd like to take credit for it, but it was Jim that came up with that great
suggestion.
Walt

On Mon, Jan 10, 2022 at 12:31 PM Michael Cheponis <
michael.cheponis@gmail.com> wrote:

> I prefer to use 1/2 wave ducks (generally, 'sleeve' dipoles) because then
> you can measure the antenna without an artificial ground; it also has the
> benefit of moving the 'high current' point halfway up the duck, into the
> air, a bit more away from one's body when talking directly into the HT.
>
> Folks should take a look at the RF absorption curves at HT frequencies --
> 144 MHz is not so great. 440 is better. Best is antenna on roof of
> vehicle, with you inside.
>
> -Mike K6THZ
>
> p,s. I like WB4ZUT's use of a pizza pan. Now, that old one in the garage
> I didn't throw out is going to have a New Life! ;-) Tnx OM.
>
>
> On Mon, Jan 10, 2022 at 10:22 AM Jim Lux <jim@luxfamily.com> wrote:
>
>> On 1/10/22 10:12 AM, Walter Egenmaier wrote:
>> > Jim, thank you for that explanation.
>> > I was definitely getting variable results with me touching or holding
>> > the antenna, but my SWR was up in the 1 to 8.2 range...way off! Guess
>> > I need to set it down and not touch it at all to get more accurate
>> > readings. I think I might someone else with an FT-70D and see if their
>> > rubber duck reads the same. I will say I had it in the car and
>> > it looks a little bent, so I may have damaged it putting it in the
>> > glove compartment when I took it off to hook up my mobile antenna to
>> > it to give it better range while driving.
>> >
>> > Now I also have another longer "rubber duck" that worked just fine
>> > that is also for 2m and 70cm.
>> >
>> > Thank you and 73's
>> > Walt
>> > WB4ZUT
>> >
>> I have a pizza pan with an SMA feedthrough connector I use for HT
>> antenna testing. Sure, it's not like a human holding the HT, but it is
>> repeatable. I set it on a cardboard box to get it away from stuff.
>>
>>
>>
>>
>>
>>
>>
>>
>>
>
>

--
Walter H. Egenmaier, O.D
EyeCare Consultants
Evansville, IN 47708
(812) 426-2020 Phone
(812) 426-2828 Fax
WB4ZUT
wegenmaier@gmail.com
http://www.eyecare-consultants.net

W0LEV 2022/01/11 00:28

Yes, when I ran the numbers through the tool provided by ARRL, our HTs fail
wrt to absorbed power. I've been using them for 40+ years, first on
2-meters, and now, mostly on 440. Yes, I've had cataract surgery and can
once again drive at night. Was that due to the RF energy from the HTs?
Heaven knows. But my sister who is roughly 2 years younger than I is just
marginal for SS paid cataract surgery. So, is it genetic? Heaven knows.

Dave - WØLEV

On Mon, Jan 10, 2022 at 11:05 PM Walter Egenmaier <wegenmaier@gmail.com>
wrote:

> I'd like to take credit for it, but it was Jim that came up with that
> great suggestion.
> Walt
>
> On Mon, Jan 10, 2022 at 12:31 PM Michael Cheponis <
> michael.cheponis@gmail.com> wrote:
>
>> I prefer to use 1/2 wave ducks (generally, 'sleeve' dipoles) because then
>> you can measure the antenna without an artificial ground; it also has the
>> benefit of moving the 'high current' point halfway up the duck, into the
>> air, a bit more away from one's body when talking directly into the HT.
>>
>> Folks should take a look at the RF absorption curves at HT frequencies --
>> 144 MHz is not so great. 440 is better. Best is antenna on roof of
>> vehicle, with you inside.
>>
>> -Mike K6THZ
>>
>> p,s. I like WB4ZUT's use of a pizza pan. Now, that old one in the garage
>> I didn't throw out is going to have a New Life! ;-) Tnx OM.
>>
>>
>> On Mon, Jan 10, 2022 at 10:22 AM Jim Lux <jim@luxfamily.com> wrote:
>>
>>> On 1/10/22 10:12 AM, Walter Egenmaier wrote:
>>> > Jim, thank you for that explanation.
>>> > I was definitely getting variable results with me touching or holding
>>> > the antenna, but my SWR was up in the 1 to 8.2 range...way off! Guess
>>> > I need to set it down and not touch it at all to get more accurate
>>> > readings. I think I might someone else with an FT-70D and see if their
>>> > rubber duck reads the same. I will say I had it in the car and
>>> > it looks a little bent, so I may have damaged it putting it in the
>>> > glove compartment when I took it off to hook up my mobile antenna to
>>> > it to give it better range while driving.
>>> >
>>> > Now I also have another longer "rubber duck" that worked just fine
>>> > that is also for 2m and 70cm.
>>> >
>>> > Thank you and 73's
>>> > Walt
>>> > WB4ZUT
>>> >
>>> I have a pizza pan with an SMA feedthrough connector I use for HT
>>> antenna testing. Sure, it's not like a human holding the HT, but it is
>>> repeatable. I set it on a cardboard box to get it away from stuff.
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>
> --
> Walter H. Egenmaier, O.D
> EyeCare Consultants
> Evansville, IN 47708
> (812) 426-2020 Phone
> (812) 426-2828 Fax
> WB4ZUT
> wegenmaier@gmail.com
> http://www.eyecare-consultants.net
>
>
>
>

--
*Dave - WØLEV*
*Just Let Darwin Work*

Walter Egenmaier 2022/01/10 19:58

Doubt RF causes cataracts but UV light does. I didn’t understand your
question that begins with, “But my sister…” Likely autocorrect error? What
is “SS” stand for?

On Mon, Jan 10, 2022 at 6:29 PM W0LEV <davearea51a@gmail.com> wrote:

> Yes, when I ran the numbers through the tool provided by ARRL, our HTs
> fail wrt to absorbed power. I've been using them for 40+ years, first on
> 2-meters, and now, mostly on 440. Yes, I've had cataract surgery and can
> once again drive at night. Was that due to the RF energy from the HTs?
> Heaven knows. But my sister who is roughly 2 years younger than I is just
> marginal for SS paid cataract surgery. So, is it genetic? Heaven knows.
>
> Dave - WØLEV
>
> On Mon, Jan 10, 2022 at 11:05 PM Walter Egenmaier <wegenmaier@gmail.com>
> wrote:
>
>> I'd like to take credit for it, but it was Jim that came up with that
>> great suggestion.
>> Walt
>>
>> On Mon, Jan 10, 2022 at 12:31 PM Michael Cheponis <
>> michael.cheponis@gmail.com> wrote:
>>
>>> I prefer to use 1/2 wave ducks (generally, 'sleeve' dipoles) because
>>> then you can measure the antenna without an artificial ground; it also has
>>> the benefit of moving the 'high current' point halfway up the duck, into
>>> the air, a bit more away from one's body when talking directly into the HT.
>>>
>>> Folks should take a look at the RF absorption curves at HT frequencies
>>> -- 144 MHz is not so great. 440 is better. Best is antenna on roof of
>>> vehicle, with you inside.
>>>
>>> -Mike K6THZ
>>>
>>> p,s. I like WB4ZUT's use of a pizza pan. Now, that old one in the
>>> garage I didn't throw out is going to have a New Life! ;-) Tnx OM.
>>>
>>>
>>> On Mon, Jan 10, 2022 at 10:22 AM Jim Lux <jim@luxfamily.com> wrote:
>>>
>>>> On 1/10/22 10:12 AM, Walter Egenmaier wrote:
>>>> > Jim, thank you for that explanation.
>>>> > I was definitely getting variable results with me touching or holding
>>>> > the antenna, but my SWR was up in the 1 to 8.2 range...way off! Guess
>>>> > I need to set it down and not touch it at all to get more accurate
>>>> > readings. I think I might someone else with an FT-70D and see if
>>>> their
>>>> > rubber duck reads the same. I will say I had it in the car and
>>>> > it looks a little bent, so I may have damaged it putting it in the
>>>> > glove compartment when I took it off to hook up my mobile antenna to
>>>> > it to give it better range while driving.
>>>> >
>>>> > Now I also have another longer "rubber duck" that worked just fine
>>>> > that is also for 2m and 70cm.
>>>> >
>>>> > Thank you and 73's
>>>> > Walt
>>>> > WB4ZUT
>>>> >
>>>> I have a pizza pan with an SMA feedthrough connector I use for HT
>>>> antenna testing. Sure, it's not like a human holding the HT, but it is
>>>> repeatable. I set it on a cardboard box to get it away from stuff.
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>
>> --
>> Walter H. Egenmaier, O.D
>> EyeCare Consultants
>> Evansville, IN 47708
>> (812) 426-2020 Phone
>> (812) 426-2828 Fax
>> WB4ZUT
>> wegenmaier@gmail.com
>> http://www.eyecare-consultants.net
>>
>>
>
> --
> *Dave - WØLEV*
> *Just Let Darwin Work*
>
>
>
> --
Walter H. Egenmaier, O.D
EyeCare Consultants
Evansville, IN 47708
(812) 426-2020 Phone
(812) 426-2828 Fax
WB4ZUT
wegenmaier@gmail.com
http://www.eyecare-consultants.net

Walter Egenmaier 2022/01/10 20:03

Correction, IR (infrared) causes cataracts. UV light is mostly blocked by
the cornea and natural human lens. That’s why glass blowers got cataracts
all the time until they wore IR protection

On Mon, Jan 10, 2022 at 7:58 PM Walter Egenmaier via groups.io <wegenmaier=
gmail.com@groups.io> wrote:

> Doubt RF causes cataracts but UV light does. I didn’t understand your
> question that begins with, “But my sister…” Likely autocorrect error? What
> is “SS” stand for?
>
> On Mon, Jan 10, 2022 at 6:29 PM W0LEV <davearea51a@gmail.com> wrote:
>
>> Yes, when I ran the numbers through the tool provided by ARRL, our HTs
>> fail wrt to absorbed power. I've been using them for 40+ years, first on
>> 2-meters, and now, mostly on 440. Yes, I've had cataract surgery and can
>> once again drive at night. Was that due to the RF energy from the HTs?
>> Heaven knows. But my sister who is roughly 2 years younger than I is just
>> marginal for SS paid cataract surgery. So, is it genetic? Heaven knows.
>>
>> Dave - WØLEV
>>
>> On Mon, Jan 10, 2022 at 11:05 PM Walter Egenmaier <wegenmaier@gmail.com>
>> wrote:
>>
>>> I'd like to take credit for it, but it was Jim that came up with that
>>> great suggestion.
>>> Walt
>>>
>>> On Mon, Jan 10, 2022 at 12:31 PM Michael Cheponis <
>>> michael.cheponis@gmail.com> wrote:
>>>
>>>> I prefer to use 1/2 wave ducks (generally, 'sleeve' dipoles) because
>>>> then you can measure the antenna without an artificial ground; it also has
>>>> the benefit of moving the 'high current' point halfway up the duck, into
>>>> the air, a bit more away from one's body when talking directly into the HT.
>>>>
>>>> Folks should take a look at the RF absorption curves at HT frequencies
>>>> -- 144 MHz is not so great. 440 is better. Best is antenna on roof of
>>>> vehicle, with you inside.
>>>>
>>>> -Mike K6THZ
>>>>
>>>> p,s. I like WB4ZUT's use of a pizza pan. Now, that old one in the
>>>> garage I didn't throw out is going to have a New Life! ;-) Tnx OM.
>>>>
>>>>
>>>> On Mon, Jan 10, 2022 at 10:22 AM Jim Lux <jim@luxfamily.com> wrote:
>>>>
>>>>> On 1/10/22 10:12 AM, Walter Egenmaier wrote:
>>>>> > Jim, thank you for that explanation.
>>>>> > I was definitely getting variable results with me touching or
>>>>> holding
>>>>> > the antenna, but my SWR was up in the 1 to 8.2 range...way off!
>>>>> Guess
>>>>> > I need to set it down and not touch it at all to get more accurate
>>>>> > readings. I think I might someone else with an FT-70D and see if
>>>>> their
>>>>> > rubber duck reads the same. I will say I had it in the car and
>>>>> > it looks a little bent, so I may have damaged it putting it in the
>>>>> > glove compartment when I took it off to hook up my mobile antenna to
>>>>> > it to give it better range while driving.
>>>>> >
>>>>> > Now I also have another longer "rubber duck" that worked just fine
>>>>> > that is also for 2m and 70cm.
>>>>> >
>>>>> > Thank you and 73's
>>>>> > Walt
>>>>> > WB4ZUT
>>>>> >
>>>>> I have a pizza pan with an SMA feedthrough connector I use for HT
>>>>> antenna testing. Sure, it's not like a human holding the HT, but it is
>>>>> repeatable. I set it on a cardboard box to get it away from stuff.
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>
>>> --
>>> Walter H. Egenmaier, O.D
>>> EyeCare Consultants
>>> Evansville, IN 47708
>>> (812) 426-2020 Phone
>>> (812) 426-2828 Fax
>>> WB4ZUT
>>> wegenmaier@gmail.com
>>> http://www.eyecare-consultants.net
>>>
>>>
>>
>> --
>> *Dave - WØLEV*
>> *Just Let Darwin Work*
>>
>> --
> Walter H. Egenmaier, O.D
> EyeCare Consultants
> Evansville, IN 47708
> (812) 426-2020 Phone
> (812) 426-2828 Fax
> WB4ZUT
> wegenmaier@gmail.com
> http://www.eyecare-consultants.net
>
>
>
> --
Walter H. Egenmaier, O.D
EyeCare Consultants
Evansville, IN 47708
(812) 426-2020 Phone
(812) 426-2828 Fax
WB4ZUT
wegenmaier@gmail.com
http://www.eyecare-consultants.net

W0LEV 2022/01/11 02:20

SS = Social Security. We are both retired.

Dave - WØLEV

On Tue, Jan 11, 2022 at 1:58 AM Walter Egenmaier <wegenmaier@gmail.com>
wrote:

> Doubt RF causes cataracts but UV light does. I didn’t understand your
> question that begins with, “But my sister…” Likely autocorrect error? What
> is “SS” stand for?
>
> On Mon, Jan 10, 2022 at 6:29 PM W0LEV <davearea51a@gmail.com> wrote:
>
>> Yes, when I ran the numbers through the tool provided by ARRL, our HTs
>> fail wrt to absorbed power. I've been using them for 40+ years, first on
>> 2-meters, and now, mostly on 440. Yes, I've had cataract surgery and can
>> once again drive at night. Was that due to the RF energy from the HTs?
>> Heaven knows. But my sister who is roughly 2 years younger than I is just
>> marginal for SS paid cataract surgery. So, is it genetic? Heaven knows.
>>
>> Dave - WØLEV
>>
>> On Mon, Jan 10, 2022 at 11:05 PM Walter Egenmaier <wegenmaier@gmail.com>
>> wrote:
>>
>>> I'd like to take credit for it, but it was Jim that came up with that
>>> great suggestion.
>>> Walt
>>>
>>> On Mon, Jan 10, 2022 at 12:31 PM Michael Cheponis <
>>> michael.cheponis@gmail.com> wrote:
>>>
>>>> I prefer to use 1/2 wave ducks (generally, 'sleeve' dipoles) because
>>>> then you can measure the antenna without an artificial ground; it also has
>>>> the benefit of moving the 'high current' point halfway up the duck, into
>>>> the air, a bit more away from one's body when talking directly into the HT.
>>>>
>>>> Folks should take a look at the RF absorption curves at HT frequencies
>>>> -- 144 MHz is not so great. 440 is better. Best is antenna on roof of
>>>> vehicle, with you inside.
>>>>
>>>> -Mike K6THZ
>>>>
>>>> p,s. I like WB4ZUT's use of a pizza pan. Now, that old one in the
>>>> garage I didn't throw out is going to have a New Life! ;-) Tnx OM.
>>>>
>>>>
>>>> On Mon, Jan 10, 2022 at 10:22 AM Jim Lux <jim@luxfamily.com> wrote:
>>>>
>>>>> On 1/10/22 10:12 AM, Walter Egenmaier wrote:
>>>>> > Jim, thank you for that explanation.
>>>>> > I was definitely getting variable results with me touching or
>>>>> holding
>>>>> > the antenna, but my SWR was up in the 1 to 8.2 range...way off!
>>>>> Guess
>>>>> > I need to set it down and not touch it at all to get more accurate
>>>>> > readings. I think I might someone else with an FT-70D and see if
>>>>> their
>>>>> > rubber duck reads the same. I will say I had it in the car and
>>>>> > it looks a little bent, so I may have damaged it putting it in the
>>>>> > glove compartment when I took it off to hook up my mobile antenna to
>>>>> > it to give it better range while driving.
>>>>> >
>>>>> > Now I also have another longer "rubber duck" that worked just fine
>>>>> > that is also for 2m and 70cm.
>>>>> >
>>>>> > Thank you and 73's
>>>>> > Walt
>>>>> > WB4ZUT
>>>>> >
>>>>> I have a pizza pan with an SMA feedthrough connector I use for HT
>>>>> antenna testing. Sure, it's not like a human holding the HT, but it is
>>>>> repeatable. I set it on a cardboard box to get it away from stuff.
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>
>>> --
>>> Walter H. Egenmaier, O.D
>>> EyeCare Consultants
>>> Evansville, IN 47708
>>> (812) 426-2020 Phone
>>> (812) 426-2828 Fax
>>> WB4ZUT
>>> wegenmaier@gmail.com
>>> http://www.eyecare-consultants.net
>>>
>>>
>>
>> --
>> *Dave - WØLEV*
>> *Just Let Darwin Work*
>>
>> --
> Walter H. Egenmaier, O.D
> EyeCare Consultants
> Evansville, IN 47708
> (812) 426-2020 Phone
> (812) 426-2828 Fax
> WB4ZUT
> wegenmaier@gmail.com
> http://www.eyecare-consultants.net
>
>
>
>

--
*Dave - WØLEV*
*Just Let Darwin Work*

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