Date   

DMR - A quick quesion

Wayne Dillon
 

Good morning all,
What are you all using to get on the Wednesday DMR net? I'm looking to maybe join in but have no clue as to what to use. Help please.
72/3 de Wayne - NQ0RP

--
 
QRP -  EFFICIENCY AND SKILL, NOT POWER. 
 
God Bless from Wayne Dillon - NQ0RP

Fate whispered to courageous "You cannot withstand the storm"
Courageous  whispered back "I am the storm"


Upcoming Event: Wednesday Evening 40 and 80 meter Nets - Wed, 06/17/2020 20:00-21:00 #cal-reminder

main@4SQRP.groups.io Calendar <main@...>
 

Reminder: Wednesday Evening 40 and 80 meter Nets

When: Wednesday, 17 June 2020, 20:00 to 21:00, (GMT-05:00) America/Chicago

Where:40 and 80 Meters

View Event

Organizer: jomatlock@...

Description: The 40 Meter Net will be at 8:00 pm central time  on 7.122 +-. QRM
NCS is WQ5RP/ACØBQ 

Wednesday evening 80 Meter CW Net. will be at  (8:30PM Central Time Wednesday). 



The 80 meter net will be called on 3.564 MHz +/- QRM.
Net control operator is Johnny ACØBQ 

* NEW *  Wednesday evening DMR Voice Net will be at (Thursday) 0300 UTC (9:00PM Central Time Wednesday/)
Four States QRP has a Brandmeister DMR Talk Group (TG31654). Join us to discuss QRP, ask questions, or just ragchew. The Wednesday net is a directed net  but any other time you may use the Talk Group to chat with other QRPers.
Net Control operator is Bert NØYJ.


NAQCC QRPp Sprint

Larry Makoski
 

DATE:  JUNE 17, 2020  (The evening of the 16th in North America.)

TIME:  0030-0230 UTC

BANDS:  80, 40, 20 (See the General Instructions page for suggested freq.)

====================

mW QRPp SPRINT RULES:

All QSOs are to made with 1-watt of output power or less.

Complete sprint rules including exchange details, operating categories,
scoring, and logging requirements should be reviewed at
<http://www.naqcc.info/sprint_rules.html>
http://www.naqcc.info/sprint_rules.html.

====================

MEMBERSHIP DATA FILES:

Membership data files for supported sprint logging applications are
available at  <http://www.naqcc.info/contests.html>
http://www.naqcc.info/contests.html.  It is very important that you use the
latest data file in your software.  It is available now for download.

====================

LOG SUBMISSIONS:

All sprint logs must be submitted through our Autologger page at
http://www.naqcc.info/autologger.php.  Directly emailed logs are no longer
accepted.  Some significant updates have been made to this page, including
some automatic error trapping and correcting.  Please carefully follow the
instructions given on the page for each of the input fields.  (A sample
Autologger page for you to practice on before the start of the sprint is
available.  See the list of useful links below.)

Logging options and specific log formatting details can be found on the
Sprint Rules page at  <http://www.naqcc.info/sprint_rules.html>
http://www.naqcc.info/sprint_rules.html.

====================

AN INTRODUCTION TO OUR NAQCC SPRINTS:

If you have been hesitant to give ham radio contesting a try you really
should consider our NAQCC sprints.  Our sprints are specifically tailored to
help new CW operators get their first contesting experience.  Our most
popular operating category is for using a straight key and this
automatically keeps the CW speeds relatively low.  Additionally the exchange
is simple and virtually everyone operating in the sprint is more than
willing to slow down or give repeats.  Once the sprint is over we make log
submission easy with our automated Autologger page.

Although scores are posted on our website and award certificates are issued,
the real goal of our sprints is not to win something.  It's to have FUN
while promoting CW QRP operating.  EVERYONE who participates in the sprint
is a WINNER, and in keeping with this philosophy we have a drawing each
month for a nice prize that all of our member participants are entered into.
It doesn't matter if you made 1 QSO or 100 QSOs, everyone has a chance to
win the prize.


Re: The mysteries of tuning a random wire

Jim, N5IB
 

Hi again Dave,

Look and see if the Nano has an option to display the reactive part as ohms instead of capacitor/inductor units.
That'll make it much easier to interpret.

For example - in your 30 m measurements.... at 10 MHz, 402 nH is +25 ohms, while 572 pF is -27 ohms. So your 30 m results show that you are actually very close to one of those zero crossings. The change in counterpoise just shifts the zero crossing a little bit either way. That's not as apparent with nH and pF.

N5IB


Re: The mysteries of tuning a random wire

Dave W0DCX
 

I just read Jim's latest post.  Very nice.  I have not yet done a full sweep, but I did try characterizing this so-called antenna for a few bands.  I think the results are consistent with what I originally posted.  But I have to admit this test in probably flawed, for example I don't think my two counterpoises are fully and fairly comparable as they are each positioned differently.  But anyway, I did the work so here are the results.  One of the most marked features is that on 30 meters (the band that behaves the best) the reactive component X is inductive with the 17' cp but capacitive with the 29' cp!  All other reactances are always capacitive.  So 30 meters seems not to care too much either way, it tunes fine with my KX2.  Also, things seem to go south on 20 meters with a longer cp in terms of SWR.  Sorry about the piecemeal telling of this sordid tale.  I will do the full sweep as Jim suggested and see what happens.  I am still learning the ins and outs of the VNA.  Table is included as both a screenshot and a Word.doc attachment.
Dave W0DCX


Re: Want to have some fun?

Michael McEwen
 

This sounds like a great idea. I'll try to get my mobile station set up on the patio.
72/73, Doc K5OSA


Want to have some fun?

Dr Jim Kennedy
 

How about this for a thought. ARRL Field Day is coming up in a few weekends. There will be a lot of CW operators working from home. Many will have limited experience with CW and will have licenses from Novice through Extra. Why not make a plan to work that contest strictly on the Novice frequencies. In that way many OPs will be able to numerous contacts, have a little fun, log some new states or counties or grid squares, help out Novices (the somewhat forgotten class of amateurs), and improve your (not that you need to) CW sending and receiving skills under contest conditions.

Wha-do-yaa-say?

You will find me on the Novice bands.
--
--
*72/73, Doc - K2PHD*
OOTC-FISTS-SKCC-NAQCC-4SQRP
OEM/RACES/ARES/CERT/SKYWARN
K2PHD@...
FN20qv
--------------------------


--
*72/73, Doc - K2PHD
OOTC#4697 - SKCC#5669 - NAQCC#9194 - FISTS#18988
OEM/RACES/ARES/CERT/SKYWARN
K2PHD@...
FN20qv*


Re: The mysteries of tuning a random wire

Jim, N5IB
 

Now, no one ever made a QSO with a computer model of an antenna, but software like 4NEC2 can be useful to gain some insights.

Here's an attached simulated sweep from 80m to 10m of Dave's 72 ft wire. The model assumed:
72 ft long, 2mm diameter copper wire, sloping from 3 ft to 35 ft
17 ft counterpoise, same wire, sloping down from 3 ft to 1.5 ft
counterpoise in the same plane as, and in same direction as, the long wire
average ground conditions

Notice how the reactive part (red curve and axis scale) swings both inductive (+) and capacitive (-) with frequency. Notice also the reactance zero crossings (resonances) where the resistive part (blue curve and axis) is either at a peak, or an some intermediate value between the peaks.

The resonances where the resistive part is at a peak represent frequencies where the wire is behaving as an end-fed multiple of a half wave wire. The other resonances correspond to frequencies where the behavior is that of an **odd** multiple of a quarter wave, end-fed, and generally easier to match.

BTW --- 4NEC2 will calculate the L and C values of a matching network - Tee, Pi, or L (high or low-pass configuration) that will match a given feedpoint.

Dave, when you get a chance to do a sweep with your Nano, we'll all be curious as to whether the general appearance of your sweep is at all similar to this simulation.

N5IB


Send in your score

John Lonigro
 

Everyone should know by now they need to submit their Second Sunday Sprint score by tomorrow at the latest (qrpcontest.com/4sqrp).  As usual, I'll tally the results tomorrow night and publish them Wednesday morning (assuming I don't forget-hi).

72,
John, AA0VE
4SQRP Contest Coordinator


Re: The mysteries of tuning a random wire

W4OED
 

As you know, long-wire antennas have a large inductive component. Some antenna couplers do not have the capacity to deal with such inductance and they rely on the operator to install the antenna coupler close to the radio. This way, the feedline should help it to deal with the extra inductance.
That is why antenna tuners for HF ship radios insert a capacitor in series after the tuning network when dealing with long-wire antennas. It is important to mention that such antenna tuners are always installed within three to six feet from the base of the antenna to avoid dealing with the feedline.
Regarding the counterpoise, I have seen great results when the counterpoise (about 1/4 wavelength of the lower transmit frequency) was installed a few inches about the ground, in line with the radiator, but OPPOSITE to it. This way, the counterpoise acts more as the other half of a dipole. It might be worth trying it.


NJQRP Skeeter Hunt numbers

Larry Makoski
 

Skeeter Hunters!

The Ninth Annual NJQRP Skeeter Hunt is set for Sunday, August 16th.

A word about Skeeter Hunt numbers as I'm already receiving e-mail requests. Tradition is that Skeeter Hunt numbers are issued as of the First Day of Summer - which this year is NEXT Saturday, June. ONLY e-mail requests sent as of 12:01 AM Saturday EDTwill be honored.

"Why/ What difference does it make?" you may well ask yourself. The answer is simple - it gives eveyone interested an equal opportunity to acquire a lower number. To some that's no big deal, but to others it's a very big deal - so everyone gets the same chance. And it also adds another level of participation that keeps YOU in the game, so to speak.

Why new numbers every year and not the same one year after year like other contests? Because not everyone can participate each year - family commitments or vacations or other things come up that prevent people from participating.

So folks, start pouring in those e-mails to w2ljqrp@... AFTER Midnight when this coming Friday turns into Saturday, here in NJ. And as always, please, please, PLEASE include your call sign, your name (that you will use when operating) and the State or Province that you will be operating from.

Hope to hear from you all real soon!

Larry W2LJ

NJQRP Skeeter Hunt Contest Manager



4SQRP Second Sunday Sprint - Sun, 06/14/2020 #cal-notice

main@4SQRP.groups.io Calendar <noreply@...>
 

4SQRP Second Sunday Sprint

When:
Sunday, 14 June 2020
19:00 to 21:00
(GMT-05:00) America/Chicago

Organizer:
John Lonigro

Description:
4SQRP Second Sunday Sprint. See http://www.4sqrp.com/4sqrpOnTheAir.php for details.


Re: Random Wire Antenna

Ronald Morrison
 

Just because an antenna can be matched doesn't mean that it is a good radiator.  For one thing, the radiation pattern gets very complex at higher freq.  Height above ground has a major impact on the vertical angle of radiation, etc.  Also, you have high loss in the coax due to the high SWR on it.  A single counterpoise will have the same problem with a reactive impedance as the "random wire" has, so it is best to have at least one 1/4 wave radial for each band. In addition, radials are lossy on the ground.  Even one foot above ground is more efficient.

Ron, K5DUZ

On Sunday, June 14, 2020, 01:35:40 PM CDT, Darryl J Kelly <kk5ib01@...> wrote:


I have a 70' end fed wire, 10' at feed end up to a tree at 25', last
20' sloping down, 9:1 unun, 50' of coax on ground, 26' counterpoise
sloping down to and on ground. High SWR 6.7 at 6 meters, most much
lower, high impedance 110, also most much lower. Tuneable on 80
through 6 meters with LDG AT-200 Pro II tuner. I have very good SWR
measurements with different random lengths from 40' to 115'. Just my
experience.
Darryl, KK5IB




Upcoming Event: 4SQRP Second Sunday Sprint - Sun, 06/14/2020 19:00-21:00 #cal-reminder

main@4SQRP.groups.io Calendar <main@...>
 

Reminder: 4SQRP Second Sunday Sprint

When: Sunday, 14 June 2020, 19:00 to 21:00, (GMT-05:00) America/Chicago

View Event

Organizer: John Lonigro

Description: 4SQRP Second Sunday Sprint. See http://www.4sqrp.com/4sqrpOnTheAir.php for details.


Random Wire Antenna

Darryl J Kelly
 

I have a 70' end fed wire, 10' at feed end up to a tree at 25', last
20' sloping down, 9:1 unun, 50' of coax on ground, 26' counterpoise
sloping down to and on ground. High SWR 6.7 at 6 meters, most much
lower, high impedance 110, also most much lower. Tuneable on 80
through 6 meters with LDG AT-200 Pro II tuner. I have very good SWR
measurements with different random lengths from 40' to 115'. Just my
experience.
Darryl, KK5IB


Re: The mysteries of tuning a random wire

J.K. Wright
 

You might enjoy this link:

Jerry, NK2C

On Sun, Jun 14, 2020, 12:24 PM Dave W0DCX <cwqrp73@...> wrote:
Jim, thanks for your mentoring.  I am going to follow up and report back with the specific data you requested.  What I am trying to do here is explore the electromagnetic behavior of random wires AND try to optimize performance of the simplest and most efficient designs possible.  So my goals are both academic and pragmatic.  My usually practice is to use a 9:1 unun to feed my random wires.  In combination with the KX2 ATU this makes almost all things possible.  But I wanted to reduce/simplify/streamline as much as possible the electronics involved so I am now going back and experimenting with random wires fed directly by the transceiver without the unun.  The idea, perhaps an erroneous one, is maximize power efficiency in the output circuit by providing a direct connection between the XCVR ATU and the antenna - no unun and no coax.  Trying to get as much oomph from my QRP output as possible.  I might be on the right track if. and that is a big if, I can get the antenna and the counterpoise perfectly optimized for a specific frequency.  Is there any validity to my thinking? Or am I just spinning my wheels and worrying too much about a little power loss.

So, in answer to some of your cogent questions; 1) no feedline - antenna and counterpoise connect directly to XCVR ATU, 2) far end of antenna is at about 35 feet, 3) counterpoise is single conductor , 4) counterpoise runs down through floor and runs along top of basement foundation wall so about 18 inches above ground, and 5) counterpoise is only 17 feet long.  Okay, that seems rather short for a 40m band counterpoise so I will try lengthening that for 40m or better yet add a second counterpoise of 33 feet.
Thanks,
Dave W0DCX


Re: The mysteries of tuning a random wire

Dave W0DCX
 

Jim, thanks for your mentoring.  I am going to follow up and report back with the specific data you requested.  What I am trying to do here is explore the electromagnetic behavior of random wires AND try to optimize performance of the simplest and most efficient designs possible.  So my goals are both academic and pragmatic.  My usually practice is to use a 9:1 unun to feed my random wires.  In combination with the KX2 ATU this makes almost all things possible.  But I wanted to reduce/simplify/streamline as much as possible the electronics involved so I am now going back and experimenting with random wires fed directly by the transceiver without the unun.  The idea, perhaps an erroneous one, is maximize power efficiency in the output circuit by providing a direct connection between the XCVR ATU and the antenna - no unun and no coax.  Trying to get as much oomph from my QRP output as possible.  I might be on the right track if. and that is a big if, I can get the antenna and the counterpoise perfectly optimized for a specific frequency.  Is there any validity to my thinking? Or am I just spinning my wheels and worrying too much about a little power loss.

So, in answer to some of your cogent questions; 1) no feedline - antenna and counterpoise connect directly to XCVR ATU, 2) far end of antenna is at about 35 feet, 3) counterpoise is single conductor , 4) counterpoise runs down through floor and runs along top of basement foundation wall so about 18 inches above ground, and 5) counterpoise is only 17 feet long.  Okay, that seems rather short for a 40m band counterpoise so I will try lengthening that for 40m or better yet add a second counterpoise of 33 feet.
Thanks,
Dave W0DCX


Re: The mysteries of tuning a random wire

Jim, N5IB
 

Go a step further with your Nano.

After getting the swr data, also get the impedance information (R +/- jX). You may find one case of high swr involves a fairly low impedance, while another case is associated with a fairly high impedance. Some tuners are happier matching one or the other. depending on their design. Especially if there is a large reactive (X) component of the impedance.

Report back what you find, and also report:
is there a feedline involved, or do the counterpoise and antenna both terminate at the rig?
how high is the far end of the antenna?
is the counterpoise a single conductor? how long?
how is the counterpoise deployed? on the ground? elevated? if so, how high?

N5IB


The mysteries of tuning a random wire

Dave W0DCX
 

Here is another antenna tuning conundrum.  This morning I hoisted up a 72-foot random wire (and deployed a counterpoise).  My calculations suggested it should tune great on 30 meters (almost exactly 3/4 wavelength) but poorly on 40 or 20 meters (close to 1/2 wave multiples).  Here is what I found in terms of SWR of the untuned antenna as determined by my NanoVNA and what I observed when I tried to achieve a good SWR match with my KX2 automatic antenna tuner.

30 meters - VNA SWR = 2.3; KX2 can tune to SWR = 1.0  : NICE!
20 meters - VNA SWR = 13.17; KX2 can tune to SWR = 1.0 : NICE BUT SURPRISED!
40 meters - VNA SWR = 4.4; KX2 can only tune to SWR = 4.4 : TOTALLY BAFFLED - WHY?

Any insights?
Dave W0DCX


Re: Question About The 4 States Antenna Tuner

David Wilcox
 

Don’t forget the screen door of your slider out to the deck.  Make sure the screen is metal, but then again the metal frame itself will work fine too.  You get a higher score if the slider looks out on a golf course.

David J. Wilcox K8WPE’s iPad

On Jun 12, 2020, at 4:55 PM, Frank Perkins <N6CES.r@...> wrote:


Hi Dave, good thinking on the rain gutter antenna. Have scraped off a little paint and clipped to a downspout on one in the past.
After all, anything metal is an antenna.
An old couch spring could become a circular polerised yagi for 3 GigaHertz!!
Frank N6CES
After

On Fri, Jun 12, 2020, 1:14 PM Dave W0DCX <cwqrp73@...> wrote:
Thank you, Jeff, for that link.  I think I have become spoiled with the marvelous internal tuner in my KX2 that will tune just about anything including the proverbial rain gutter.
Dave