Date   

Mobile antenna placement and patterns

Peter, NN9K #2629
 

I just uploaded a file --  2007_MARAC_Bakeoff_Results.pdf and although it is "old" data it is still relevant today. It was probably the most comprehensive mobile antenna testing I have seen and participated in. Take your time reading it and hopefully it will help you make informed mobile antenna decisions.

RF problems during mobile operation. The Icom 7000 was very prone to RF problems even to the point of shutting of shutting down the radio. A simple torrid choke on the antenna lead would solve the problem. And I suspect the newer Icoms may also be a bit sensitive to RF on the feedline also and possibly any device attached to the radio could be affected also.

One more comment -- mag-mounts need to be grounded! A separate ground strap from the mount to a good ground point on the vehicle will make a difference in SWR and radiation pattern. Use good heavy braid and if done carefully will help keep the mount in the vehicle during sudden stops.
--
Peter, NN9K


Re: KC3EF EL39

Bill-N7RI
 

Thanks Dick

Bill
N7RI
070-1191


On Thu, Apr 22, 2021, 6:57 AM Richard Rohrer <kc3ef@...> wrote:
Will be in EL39 in afternoon.  Will let you know when getting near.  

Dick


Re: KC3EF EL39

Richard Rohrer
 

Will be in EL39 in afternoon.  Will let you know when getting near.  

Dick


Re: KC3EF EL39

Bill-N7RI
 

I definitely can use EL39 , and 59 depending on which way you are headed.
Bill
N7RI

On Wed, Apr 21, 2021 at 9:40 PM Richard Rohrer <kc3ef@...> wrote:
We will be in EL39 tomorrow if anyone still needs this grid.  Send me an email to kc3er at arrl.net.  Will probably be there in the afternoon.
--
Dick - KC3EF
070 - 747



--
Bill Fults
N7RI
PODXS 070-1170


KC3EF EL39

Richard Rohrer
 

We will be in EL39 tomorrow if anyone still needs this grid.  Send me an email to kc3er at arrl.net.  Will probably be there in the afternoon.
--
Dick - KC3EF
070 - 747


Re: KC3EF 4/20 After Action Report

Richard Rohrer
 

Hi Rick,

Kathy says thanks for your kind comments, but she still is not going to EL88, hi hi.  She think we should get together and spend the $100 and go to Dry Torguas.

73
Dick - KC3ER


Re: KC3EF Mobile Equipmemt

Richard Rohrer
 

Hi Bob, 

I found on this trip that I had more problems with RF in the computer than I have ever had.  Reduced the power to 50watts and that seemed to solve the problem.  When we return to MD I am going to experiment with the setup and see if I can find out a better solution.  Since running mobile I think with the less than optimum antenna the more power is better. 

From my experience I found that sometimes some small changes in cabling can cause problems. 

73
Dick - KC3EF 


Re: KC3EF 4/20 After Action Report

Richard Rohrer
 

Hi Steve,

To answer your questions: 

1.  The mount is on the left tail light of the mini-van. 
2.  The bottom quarter/third of the hamstick is near the van body.
3.  It sticks out to the side and some what of the back. 

I chose this method, since the van has sensors on the rear bumper which trigger if any thing is around the back of the vehicle.  I had previous experience with having a ham stick mounted on a mag mount and it was fine until the xyl hit 70 mph and it flew off the back of the vehicle.  

Kathy, my xyl, has often wondered if position of the van would improve propagation in a specific direction.  She thinks that doing the experiment you proposed would be great to do.  She is a post masters nurse and computer person, so this seems like a neat idea to her.  We are going to be in South Carolina next month and could drive around the island and send test transmissions.  We will be in Tennessee in June and could do the same thing.  In July we will be in Maryland for work and could also do the same type of experiment.  It would be interesting to get several 070 members to participate and see what happens.  

73
Dick - KC3EF


Re: KC3EF Mobile Equipmemt

Bob Motyl KK6KMU
 

Dick,
Thanks for replying.  I just got a new laptop with similar specs.  Still working out the bugs.  I think I'm still getting RF to interfere with the computer.  Going to try different USB cable and some ferrite beads.  I use my ICOM IC7200. a hamstick antenna and a 30 AMP-HR battery.  Going to get a solar panel eventually to charge the battery.

Thanks again,
Bob KK6KMU


Re: KC3EF Mobile Equipmemt

Richard Rohrer
 

Hi Steve,

That is a good suggestion, but our mini-van has a built-in 120vac inverter.  The xyl says I am too lazy to crawl in the back and hook up my power supply for the computer.  I guess she is right, hi hi. 

73
Dick - KC3EF


Re: KC3EF 4/20 After Action Report

 

It might also be interesting to add a 2nd Ham Stick off the front, and phase them. They'd "fire" broadside, And I'd be pleased to donate a 20m stick and the harness if you'd like to try, John.
The harness would be 1/4 wavelength, X the velocity factor of the RG-6 phasing coax.
I've done that before, and the +++ was that it improved my receive a few db.'s. Receive is based almost entirely on resonant capture area.
Milt.
N6MG
070-650

-----Original Message-----
From: Steve W3HF <w3hf@...>
To: main@070Club.groups.io
Sent: Wed, Apr 21, 2021 10:09 am
Subject: Re: [070Club] KC3EF 4/20 After Action Report

Thinking about this and Dick's description of his setup (hamstick on a tail light mount), I have a few questions and a speculation:

- What does the tail light mount look like? I presume it's a bracket that sticks out between the tail light lens and the metal body of the car.
- Which direction does it stick out--to the back or to the side?
- Which tail light is it on?
- How much of the hamstick extends above the top of the T&C minivan? (Or what fraction of it is below the roof line?)

I wonder if part of this could be the direction the car is pointing and thus the location/orientation of the ground plane, which is affected by the answers to the questions above. It might be an interesting experiment some time to find a large empty parking lot and ask Kathy to drive around the perimeter so that the car ends up rotating 360 degrees (multiple times). If we had multiple stations listening, all in different directions, we might be able to get an idea of the pattern the antenna-on-car generates.

And if someone is good with antenna modeling software, we could compare the experimental pattern with an analytical prediction.

Steve
W3HF


Re: KC3EF 4/20 After Action Report

Jerry N9AVY
 

My 2 cents worth ...

Not an ideal spot to mount HF antenna. Years ago I had a minivan and mounted antenna on left rear quarter panel about half ways up. It did okay mostly. Any higher and I hit overhead wires which were sometimes too low or low overpasses. Everything worked pretty well until I got new van and mounted the High Sierra HF-1500 a bit lower... some impatient person passed me on left trying to get into left turn lane. Driving a big, black muscle car (her boyfriend's) she had a nice white stripe from front to back. Sure she heard about it from BF.  The high Sierra was destroyed and before I could get replacement parts High Sierra went belly up.  (Deductible was more than parts !)

Eventually went with 3 magnet mount on roof with ham stiks which worked fine except on 40/80m (wind loading problems pulled antenna off - and mag mount).  This worked okay until I worked for a company with said "NO" to ham radio. Was SSB back in those days and enjoyed whizzing alone highway yakking with hams in Europe & Australia.

A ham stik mounted in center of van roof is what works and gives best radiation pattern, but clearance to tip has to be less than 13" 6" otherwise you'll have problems with overpasses and drive up windows. Yes, I lost a few Ham Stiks to drive up windows because I was too lazy to get out a walk !

Am sure there is info somewhere on net about mobile antenna installs, but one needs to hunt for it.

Jerry N9AVY


On Wednesday, April 21, 2021, 12:09:22 PM CDT, Steve W3HF <w3hf@...> wrote:


Thinking about this and Dick's description of his setup (hamstick on a tail light mount), I have a few questions and a speculation:

- What does the tail light mount look like? I presume it's a bracket that sticks out between the tail light lens and the metal body of the car.
- Which direction does it stick out--to the back or to the side?
- Which tail light is it on?
- How much of the hamstick extends above the top of the T&C minivan? (Or what fraction of it is below the roof line?)

I wonder if part of this could be the direction the car is pointing and thus the location/orientation of the ground plane, which is affected by the answers to the questions above. It might be an interesting experiment some time to find a large empty parking lot and ask Kathy to drive around the perimeter so that the car ends up rotating 360 degrees (multiple times). If we had multiple stations listening, all in different directions, we might be able to get an idea of the pattern the antenna-on-car generates.

And if someone is good with antenna modeling software, we could compare the experimental pattern with an analytical prediction.

Steve
W3HF


Re: KC3EF 4/20 After Action Report

Steve W3HF
 

Thinking about this and Dick's description of his setup (hamstick on a tail light mount), I have a few questions and a speculation:

- What does the tail light mount look like? I presume it's a bracket that sticks out between the tail light lens and the metal body of the car.
- Which direction does it stick out--to the back or to the side?
- Which tail light is it on?
- How much of the hamstick extends above the top of the T&C minivan? (Or what fraction of it is below the roof line?)

I wonder if part of this could be the direction the car is pointing and thus the location/orientation of the ground plane, which is affected by the answers to the questions above. It might be an interesting experiment some time to find a large empty parking lot and ask Kathy to drive around the perimeter so that the car ends up rotating 360 degrees (multiple times). If we had multiple stations listening, all in different directions, we might be able to get an idea of the pattern the antenna-on-car generates.

And if someone is good with antenna modeling software, we could compare the experimental pattern with an analytical prediction.

Steve
W3HF


RC3 Standings

Jim K5SP
 

The RC3 Leaderboard and Top Ten pages of the website have been updated to reflect the standings through the 31 Flavors Contest.

Good job to all!

73

Jim K5SP


--
Jim,  K5SP #483
Executive Director/Member Services Director


Re: KC3EF 4/20 After Action Report

Rick - N7WE
 

Well prop was WEIRD yesterday to say the least!  At times Dick you were S9+ with 100% copy on this end - yet you couldn't hear me.  At other times, you would suddenly disappear off the waterfall.  I've never operated HF mobile, but from operating HF portable I have to wonder if local terrain plays a major role.  I know when portable I have been in places where I was getting out (feedback via internet), but was receiving nothing.  And that was with a 24' EagleOne off the back of the motorhome.  

Thanks so much for doing all these road trips and grids.  And for your perserverence despite tough conditions.  Special thanks to Kathy too!  If she didn't do the route plan and the driving, this would not be possible!

I'll be looking for you in EL59.  If we make it, it will finish LA for me.
--
Rick - N7WE
070 - #1602


Re: KC3EF Mobile Equipmemt

Steve W3HF
 

Dick -

With all the mobile operation you do, you might consider getting a car charging adapter for it. I bought a generic one about 12 years ago, that had switchable voltage and about a dozen interchangeable connectors for the computer end of the cable. I recall it cost only about $20. You wouldn't have to be so careful about maintaining battery charge during the drives.

Thanks again for all the tries yesterday afternoon. I was seeing the stations in Florida (N7WE and KC3FL) and Jerry in Illinois, but never had any copy to my southwest, where you were.

Steve
W3HF


KC3EF Mobile Equipmemt

Richard Rohrer
 

HI Bob,

My mobile station consist of an IC7100 transceiver feeding a 20 mtr hamstick antenna mounted on a taillight mount on the rear of the Town & Country mini-van.  I like the 7100 since the control head fits on the front cup holder and the body goes under the front seat.  Since control and audio goes thru the USB I don't need the Signallink like I did with the 7000 I use to have.  The 7100 also runs much cooler.  For a computer I use an Asus Zenbook 360, with 8 Gbyte memory and 237 Gbyle SSD HD. I like the SSD since it starts in a few seconds.  I use this as my main computer with two monitors at home and also mobile/portable.  It has a 10.5 inch touch screen and will work as a tablet.  I use Win10 with Flidigi for most work.  I use N1MM for RTTY contest and ACL for logging. 
--
Dick - KC3EF
070 - 747


Re: PM Cell?

Richard Rohrer
 

Don't worry Jerry, I just figured out how to send a group text.  When I worked for NASA contractor on Space Shuttle telemetry I called our real estate agent one day when sell our house in Annapolis, MD and she told me she had trouble with the new phone system putting people on hold or transferring.  I told her not to feel bad about it, I was an engineer for the Space Shuttle Program and had the same problem.  I was use to the old phones that had buttons on them you put on hold or transferred, not hitting the cradle to do different things.  Like radios now, I think back to my old 6 mtr transceiver that had three or four controls, not many menus, etc.  

73
Dick - KC3EF


KC3EF 4/20 After Action Report

Richard Rohrer
 

Well, today was better and worse that 4/19.  We started heading for DL99 and I went on the air in DM09.  Saw Barry, VA7GEM calling but could not make contact.  Then a quick QSO with Rick, N7WE just before the grid, so he was waiting for me to hit the grid.  When we hit the grid, saw Jerry, N9AVY calling with a really strong trace.  When I answered him signal went down quite a bit, but made the contact.  Tried calling Rick, N7WE for quite a while with no success.  Saw a W9 pop up briefly, but did not get a complete call. Tried calling Steve, W3HF, with no luck.  Stopped for lunch at Amistad Natural Area with a nice view of a lake on the Rio Grande.  Saw several birds, including a Hooded Oriole, which is a life bird for us. 

Headed for EL98 in Eagle Pass, TX and started calling while still in EL99.  Worked John, KC3FL who had a great signal into TX.  After that finally worked Rick, N7WE not great copy, but good enough for a complete contact.  When we got into EL89 worked Jerry, N9AVY with a good signal and then worked John, KC3FL.  Called Steve W3HF many times with no success.  We finally exited the grid with no success for a QSO with W3HF and headed back to San Antonio.  

The bands were not very good to us PSK31 operators today.  Saw signals appear and disappeared before a contact could be made.  Hopefully propagation will improve over the next few months.  We are still planning on activating EL59 in LA as long as the weather cooperates.  

Thanks to all who tried to contact us during this trip.  

73 
Dick - KC3EF
--
Dick - KC3EF
070 - 747


31 Flavors Contest 2021 - Results

stan W9SMR
 

31 Flavors Contest 2021 results are in. A very BIG THANK YOU to David, K9DWR, for again creating the upload link and parsing the results.

Top Dawg and First Place in Medium Power is John, KC3FL with 113 QSOs, 13 DXCC and 70 SPC/Mult for 9,379 Total Points Those are the highest scores in every category.

Second Place in Medium Power was last year’s contest winner, Lee, N5SLY with 99 QSOs, 12 DXCC and 68 SPC/Mult for 7.920 Total Points. Very impressive performance, but not quite enough to beat John.

Third Place in Medium Power was Robert, KF3AA with 3,055 Total Points.

First Place in Low Power was Alan, KA5VZG with 51 QSOs, 6 DXCC, 30 SPC/Mult for 1,836 Total Points.

Second Place in Low Power was Jim, K5SP with 1,628 Total Points. Jim managed to take a few hours off from his Executive Director role to enjoy the Contest.

Third Place in Low Power was Steve, W3HF with 448 Total Points.

First Place in QRP Power was Peter, NN9K with 39 QSOs, 2 DXCC, 18 SPC/mult and 780 Total Points.

Second Place in QRP Power was Don, KM4UDX with 140 Total Points.

Third Place in QRP Power was non-member Pieter, VE9BWK of Fredericton, NB with 99 Total Points. Thank you, Pieter for joining us!

Winners in each Category are summarized in the table below.

RESULTS - 31 FLAVORS CONTEST - 2021

CALL

#070

QSO

DXCC

SPC/Modes

TOTAL

 

NOTES

Medium Power 50W

 

 

 

 

 

KC3FL

2566

113

13

70

9379

 

Top Dawg - 1st Place Medium Power

N5SLY

2241

99

12

68

7920

 

2nd Place Medium Power

KF3AA

124

65

13

34

3055

 

3rd Place Medium Power

Low Power 25W

 

 

 

 

 

KA5VZG

1509

51

6

30

1836

 

1st Place Low Power

K5SP

483

44

9

28

1628

 

2nd Place Low Power

W3HF

25

28

3

13

448

 

3rd Place Low Power

QRP Power  5W

 

 

 

 

 

NN9K

2629

39

2

18

780

 

1st Place QRP Power

KM4UDX

2752

10

6

8

140

 

2nd Place QRP Power

VE9BWK

0

11

2

7

99

 

3rd Place QRP Power

 

This was an 18 hour long window, 6 hour Sprint contest on the 20M band, So, we had to carefully choose the operating times to maximize our results.

This contest is unique in allowing us to compare performance of 6 PSK modes. I don’t know about you, but of these my favorite Flavor by far is BPSK-31. How many of you worked a call on all 6 Modes? Like grabbing a 6-Pack! That became a challenge at times!

We had 52 logs submitted, up from 45 logs last year. Conditions will hopefully continue to improve as we enter Solar Cycle-25

Last year’s 3rd place winner In the Medium Power Category was Barry, VA7GEM. This year, unfortunately, Barry’s submitted log showed no contacts in spite of a valiant effort.
Again he grabs First Place in the “I Tried” category.

Don’t give up, Barry, we’ll keep looking for you from the Pacific North West.

We had 7 non-members submit logs. They were Caleb, KD9PEV; Jeffrey, KF5KWO; Gerald, VE7BGP; Pieter, VE9BWK; Warren, W4FLL; Mark, W6IA; and Van, WA2PCN.

Thank you all for competing and submitting your logs. We hope enjoyed the Contest and that you will join us soon.

Full results will be uploaded to the 070 Club and 070 Club Contest Reflectors. See Groups.io for info on viewing uploaded files: main@070Club.groups.io | Files


The next PODXS 070 Event is
:

Endorsement Daze #4 – LONP and CHIMP CHASE

Saturday, May 22 and Sunday May 23
This is our 4th Endorsement Daze Event. IT IS NOT A CONTEST.

 

Our NEXT CONTEST will be the Three Day Weekend starting 0000 UTC on Friday, June 4 through 2359 on Sunday, June 6.  This Contest includes all bands from 160M to 6M (no WARC Bands).

See Three Day Weekend Rules at: Rules - Three Day Weekend

73,

 Stan

W9SMR - 070  #1611

PODXS 070 - PR Director

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