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147.210 Repeater OTA

As of January 2022, the 147.210 MHz W0IN repeater is fully operational at the new site located in SW Joplin. In addition, the JOPLIN APRS Digipeater on 144.390 MHz, now has a GATEWAY installed at the site. The UHF DMR repeater on 444.500 MHz is off the air due to what appears to be a lightning strike. Winter weather precludes service at the top of the tower until early spring. Temporary options are being formulated. The 145.190MHz W0IN repeater, although fully operational, is off the air while a new site is being located more central in the county.

Other repeaters in the area:

  • For SkyWarn – the 145.350(-) 91.5 PL N0NWS repeater can be linked to the regional SkyWarn system.
  • The 145.390(-) 91.5 PL KM0HP repeater is part of the SMLRS wide coverage linked system.
  • The 147.000(+) (open) WB0IYC repeater located in downtown Joplin with local coverage.

EZNEC Training – N8GOU

On the 16th of December 2017 John Frederick, N8GOU, will conduct a 4-hour hands on training session on the Basics of Using EZNEC Software. The session will be broken into these topic areas; general navigation, modeling a simple dipole, modeling a loop, modifications of an existing EZNEC file, creating SWR plots, and finally creating far field plots. After attending you should be able to use the software and begin to explore the more complicated uses of it.

EZNEC Training Flyer

Receiver Project Notes and Errata

Here’s a collection of all the notes I’ve gathered about the project, along with updated schematics:

JARC Receiver Sheet 1 of 4 (updated)

JARC Receiver Sheet 2 of 4 (updated)

JARC Receiver Sheet 3 of 4 (updated)

JARC Receiver Sheet 4 of 4 (updated)

The capacitors are all marked, but the text is 0.5mm high, so visors or magnifiers are needed to read them. LED lighting washes out so use incandescent when sorting. Visors are available around town, like Harbor Freight.

The little blue capacitors are all measured in picoFarads, and marked with 3 digits. The first two are significant digits and the third the number of zeros. For example: 271 = 270pF while 103 = 10000pF.

Resistor values can be verified by any ohmmeter (also available at Harbor Freight).

Varactor diodes D101 and D102 are reversed from what is shown on the board. I installed only one of them and it covered the entire 40m band with the potentiometer provided. I fully expect that the tuning will extend across the entire 40m band but resistors associated with tuning may need to be tweaked into the band.

If you have not applied the Q-dope to the toroid coils you can either stop by here (Jim’s shop) after they are wound, or make your own.

The blue resistors are 1% parts and are needed for the audio filter. Unlike the 5% (tan) resistors, they have an additional digit in the identification band. For example: 39.2 kOhm – Orange, White, Red, Red, Brown – 3 9 2 (00) 1% (the 2nd red = two zeros).

I recommend that you assemble the board in layers, starting with the lowest parts first.

Boards are through-hole plated, so you only need to solder on the back side.

Wire jumpers are placed across pins 1-2 on P6 P7 and P8.

See the PDF regarding the orientation of L102. The TAPPED winding terminal is near C105.

When the toroids are mounted and soldered, they need to be cemented down to eliminate vibration.

The orientation of SBL-1 MIXER is important. Pin 1 is denoted by a different color sealant (blue).

The ICs, U1 and U2 are marked by a dot or notch at the end where pin 1 resides. On the layout U1 and U2 show a notch.

The blue capacitor marked 4R7 is 4.7 pF and is a coupling capacitor in the oscillator circuit.

The rust colored capacitors are for bypassing and are marked 473 (0.047uF) and 104 (0.1uF).

When you are preparing to install your toroids, the copper wire is insulated. “Magnet wire” is copper wire with a thin coating of varnish on it for insulation. This is done so that you can maximize the number of turns in a small space (for magnetic coupling). The varnish gives the wire a darker color, some were even green. The coating must be removed before you can solder to the copper wire.

Simply heat up your iron (hotter) and apply solder to the tip and the wire. Slide the iron along the wire while applying some solder. Heat will darken and eventually cause the varnish to come off. You can also lightly scrape the wire to remove the varnish. In any case, be sure to tin the wire before inserting into the board for soldering. Having the solder on the wire makes it much easier.

WFD 2017 Details

Here is an update from Matt regarding WFD operations:

Winter Field Day will soon be upon us!  To make this a great event we need your participation. Come out for a few minutes or come out for the full 24 hours.
We’ll start setup at 9:00AM on Saturday 28 January 2017 at the Sarcoxie High School Football field.  This is a great opportunity.  Thanks to Scott W7NYD and the Sarcoxie community for the use of their facilities.  We will have access to heated concession stand and bathroom facilities there.  Note that all operations will be conducted outside.  We’ll be operating 2 stations.  Want to work some CW?  Please do!  Bring your key.  Want to work some digital?  Please do!  Bring whatever additional gear you need.  We’ll provide the radio.
Operation will be 24 hours continuous from 1300 on 28 January to 1300 on 29 January.
Additional information can be found at the following website. Please review the rules and print yourself some logging sheets just in case.  Note that we are planning on computer logging but always be prepared.  Right?
To pull this off the club needs your help. 
Please let me know if you’re willing to sign up for one of the following tasks/needs.
Pop up tent with sides – Would be great to have two.  David Surgi is brining one.  Anyone else have one that they would be willing to bring out to the site for us to use for the weekend?
Tables – We need for of the folding tables like we commonly use at field day during the summer.
Generator and radios – we need someone to get with John Fredricks and Jason Arends to retrieve the club radios and generators and deliver them to the site.
Antennas – Have a great antenna that allows you to hear a gnat fart in New York City?  Can you bring it out?  (We will have various dipoles on had for use but if you have something you want to try out or show off bring it out!  We will launch it!)
Seating – Bring your own chairs
Headphones – We need at least four sets and some splitters for loggers and operators.  Any volunteers?  Bring your favorite set if you want to use them while operating or logging.
3 proper temporary ground rods – anyone have these?
Cooks – Any grill masters out there?  Would be great to have someone to assist with manning the grill for supper Saturday and Breakfast Sunday.
Water – would be great if someone would be willing to pick up a case of bottle water and bring it out.  I’ll get you reimbursed for the cost.
Food – I’ll bring out the food.  Any special requests for Saturday supper or Sunday breakfast?
Dress appropriately for the weather and be prepared for rapid changes in the weather.  Could be short sleeves or parkas and mittens.  You never know around here.
Logging:  Anyone out there good with software and networking?  Can you get the logging computers and a router together and set things up for us?  Please let me know.  The logging software we use for ARRL field day also has a version specifically designed for winter field day.  Not sure if we purchased rights to this part of the software or not. Can you look into this for us?
Satellite operations – Really need someone to provide proper gear and work some sats for us.  Huge bonus for working sats.  If you enjoy this please consider bringing out your gear.  Get us those huge bonus points and show the rest of us what it’s all about.
Everything else – Bring whatever you would bring for field operations operating by yourself.  Show of your gear!  Share your gear if we need it.  Bring your relics and junk if you like.  We could make a tailgate sale out of this to boot  if people want to.
Planning:  This is just the start.  I need your help to make sure this is a great Winter Field Day.  Assistance with planning and thinking of all the particulars we need to deal with in the next 2 weeks is greatly appreciated.
Matt Bernhagen


2017 Meeting Location Update

The meeting location for the rest of the year has been confirmed. Starting with the January program meeting on the 24th, all JARC meetings will take place in the Conference Room 2 at Mercy Hospital, 100 Mercy Way, Joplin, MO 64804.

Use the Northeast entrance:

Details on entrance to use for JARC Meeting Location

Do not use the Emergency, Clinic, or Cancer Center entrances. The meeting room is on the 2nd floor. After entering the Hospital, take the elevator or stairs to Floor 2. Turn left toward the Gift Shop, and walk past it. On the right side just past the Gift Shop you will see the conference rooms. Here is a link to an interactive floor map of the facility: map.

2017 WFD

Winter Field Day in 2017 will be January 28/29 from 1900 UTC to 1900 UTC. This year, we are planning on setting up an outdoor operation at the high school in Sarcoxie, MO (101 S 17th St, Sarcoxie, MO 64862). We will likely be at the football field or baseball diamond, look for the yellow sign, popup canopies, and long dipole strung up somewhere.

We invite all hams to come out and make a few contacts, hope to see you there!

2017 Meeting Location

So far, our meeting location for the January 2017 meetings will remain at the Red Cross building. There was a mention at the Holiday Dinner of possibly meeting at a conference room at Mercy Hospital, however we haven’t been able to solidify that reservation at this time.

Voting on Amending Constitution – Online and Nov 8


If you are a paid member of JARC with an email address on file, you should have received an email this morning with a link to vote on the proposed amendement to the JARC Constitution and Bylaws. The full text can be found here:
Voting will occur at the business meeting on Nov 8, however we are also doing an online vote to try to reach all members. You can either wait to vote at the business meeting or vote online anytime between now and the meeting. Online voting will close 30 mins prior to the meeting time at 7p. I will have a list of those who voted online so we don’t duplicate votes.
The reason we are doing it this way is that the current constitution requires a 2/3 vote of all members to amend the constitution, and with our regular meeting turnout, we cannot reach enough people.
If you did not get an email and think you should have, please let me know and I can give you login information for the ballot site. Either reply here or email me at K0JAA at ARRL.NET
Remember that our annual officer election is also Nov 8, but we do not have an online ballot for that.
Jason Arends K0JAA
JARC Secretary

2016 Field Day

Joplin ARC will be setting up in the usual spot again this year – Dover Hill off North Main in Joplin. We will be running a couple HF stations, VHF, and a GOTA station so come out and Get On The Air!

We’ll be setting up Friday evening and Saturday morning, then running the entire duration of the event, overnight to Sunday. Dinner, Breakfast, and Lunch will be provided for operators, we have a tent to operate out of and you are welcome to bring a tent if you want to stay overnight also.

If you have an antenna or radio you want to bring out and try, let John Frederick know so we can coordinate it and put you in the schedule. We need to make sure we don’t have more than a certain number of stations on the air for our class at any given time.

If you have a certain time you definitely want to operate, also let John know so he can put you on the schedule.


See below for the Field Day Schedule (times CDT):

  • 24 June – Friday
    • 1900 – 2100 – ¬†Antenna setup @ site
  • 25 June – Saturday
    • 0700 – Setup activity starts
    • 1200 – Field Day operation “A” shift starts
    • 1500 – FD OPR “B” shift starts
    • 1800 – FD OPR “C” shift starts
    • 1800 (approx) – Dinner for Field Day operators
    • 2100 – FD OPR “D” shift starts
  • 26 June – Sunday
    • 0000 – FD OPR “E” shift starts
    • 0300 – FD OPR “F” shift starts
    • 0600 – FD OPR “G” shift starts
    • 0730 – Breakfast for FD operators
    • 0900 – FD OPR “H” shift starts
    • 1130 – Lunch for FD operators
    • 1200 – FD OPR “I” shift starts
    • 1500 – FD Operations end, site tear down begins
    • 1900 – Site tear down complete