Bandpass filters for POTA

This is N2JIM, Jim, and I’m here to discuss an exciting development in our ongoing quest to optimize our Parks on the Air (POTA) activations.

Recently, Rick and I have been experimenting with a technological solution to mitigate RF interference when multiple operators are activating within close proximity: Bandpass Filters.

The issue arises when several of us activate in the same park, even when operating on different bands. This proximity results in QRM or human-generated RF interference, leading to potential disruption in communication.
To address this, we have been testing non-powered Bandpass Filters, compact devices approximately the size of your fist and featuring two SO 239 ports. These filters are placed in-line between the radio and antenna, connected with a short coax jumper. It’s important to note that these filters are not bi-directional, so proper installation with the radio and antenna connected to the correct sides is essential.
The Bandpass Filter functions by filtering out RF signals outside a particular band. This effectively minimizes QRM from nearby activators. Our tests have shown promising results, indicating that these devices are highly effective in resolving interference issues.
Currently, the Bandpass Filters we have are single-band only, requiring a filter change when switching bands. However, we’ve found them to be a cost-effective solution for POTA enthusiasts.

You can purchase Bandpass Filters from various suppliers, including DX Engineering for around $165 each. However, we were able to find them on Aliexpress for approximately $50 each. It’s worth exploring Aliexpress for various options, as prices may vary. Try using search terms like “bandpass filter 28” to yield relevant results. Be aware that these filters are sourced from China, with an estimated delivery time of about ten days.

Rick would like to share a quick tip on international orders: always use a credit card when purchasing from overseas suppliers. Credit cards offer more robust global consumer protection compared to debit cards. This is particularly important in situations like his, where he was able to obtain charge-back refunds for undelivered filters, thanks to the protection provided by using a credit card.

We’re excited to continue refining our POTA activations with these Bandpass Filters and look forward to seeing you all at the park soon.
Best regards,
N2JIM (Jim) & KF0RIK (Rick)

Feb 4 Flash POTA — Good fun – Nearly 200 contacts made by the group.

Ricks Screen Window Ground Plain     KF0RIK Ricks 897D   KF0RIK Rick ‘s – Wadio Wagon KCf0SYD Joe on his first POTA    Pop-up POTA Shack  KE0PMW Eriks Cha Delta Loop


N2Jim on his walk-abouts between stations



   Erik KE0PMW doiing QRP from car

ARES Deployment Vests

ARES  Deployment Vest

$20.00 via ARRL + Shipping

ARRL – ARES Deployment Vest Order Page

ARES Deployment Vest

Mesh vest with large front and back reflector panels. Pocket with ARES logo and mike clip on front and imprinted with “AMATEUR RADIO EMERGENCY COMMUNICATIONS” on the back side.

Note: ARES Standardized Apparel

ARES members, while activated, deployed, in community service activities or otherwise on duty shall wear over their normal apparel, at minimum, a florescent green ANSI Class 2 reflective, 100% polyester vest.

The vest shall be decorated in the following manner:

On the Back:
In minimum 2″ lettering, Arial Black font, black in color, imprinted above the horizontal reflective tape:


Those in a leadership position may add their title (SEC, DIRECTOR, EC, PIO, etc) below the words “Emergency Communications” in not less than 3″ tall font, black. (Under the lower reflective stripe).

Local jurisdictions may elect to add their organization name above the words “Amateur Radio” with no larger than 1″ Arial Black lettering, color black.

On the Front:
On the Left Chest, the ARES logo, minimum 3.5-inch diameter, black in color, negative background.
The Right Chest shall remain blank so as to allow wearer to affix their ARES or ARRL name badge.

Vests may have zip or Velcro type front closures. Members may choose vests with or without pockets, at their own discretion. Other apparel, such as short and long sleeve tee shirts, jackets and coats are approved for member use as long as the garments meet the same color, ANSI Class 2, lettering and decoration standard. A waiver of this standard may be given by an SEC for specific purposes with good cause.

We know that many people already have some form of special clothing they purchased. As these are worn out they should be replaced with clothing meeting the new standards.

Google ‘ARES VESTS’ for many options.

2023 ARRL Field Day

Please join us on 24, 25 June at Vegsund County Park for the Annual ARRL Field Day!

The Isanti County Radio Club will be there with radios set up showing:

  • contesting
  • making long-distance contacts
  • communicating with digital modes
  • explaining emergency communications
  • other cool topics

Come learn about Amateur Radio and just hang out and have fun with us!

The ICRC Field Day begins at 10 am on Saturday and runs through the night until 12 pm Sunday.   Participants camp overnight in their personal campers, tents, or vans and provide their own meals, and beverages  There is no power grid electricity at the location.  Part of the emergency preparedness aspects demonstrated is using temporary lodging, emergency power to operate HAM radio equipment, making radio contacts locally and outside of the area, and preparing meals outdoors without electrical grid power.  The park does have restrooms.
ARRL Field day includes a DX fun contest for making contacts.

Other Information:

Update: (05/03/23)

Authorization to start using the park for setup on Friday June 23 at 6pm has been approved.  Also, a clarification was made that all vehicles, campers, screen tents, etc must remain on the asphalt.   No sleeping in tents – hard-sided RVs only.  (Yes, It would be a good question)  (bears?)

  • Cell phone users will find signal availability at the park spotty and may need to relocate to get a signal.
  • Participants should have contingencies in mind to deal with high winds for antennas, canopies, etc.
  • Severe weather may require cancelation or termination of the event. This will be decided by the SkyWarn team or Project captain on the ground at the time or before the event.
  • It is a small parking lot. Keep in mind that residents use the park for walking and recreation and will require adequate parking spaces near the building.   Field Day participants should set up on the West end of the parking lot.
  • Any tripping hazards ie guy wires or antennas should be marked with ribbons or cones.
  • Consider bringing fishing equipment, bicycles, kites, skateboards, or other playthings for children.
  • Mosquitos, bugs, and wood ticks can be a problem.  Be prepared.
  • There is little natural shade.  Be prepared to create your own.

Parking Area:

Designated Event Captain:

Erik Holm – KE0PMW

ARRL Field Day T-Shirts
ARRL Field Day Home

2023 ARRL Field Day Contest Rules


2023 Birkie-Kortie

2023 Birkie-Kortie

Another Birkie-Kortie year under the belt! This year was just as fun, or more, than last year! There were three of us from ICRC: me (KF0DEK), Shane (KD9NJJ), and Rick (KF0RIK). Rick was the new guy, and was set to work with me at the

Gravel Pit checkpoint but, due to a last-minute staffing issue, manned the Hatchery Creek (or “fish farm” or “hatchery river”, depending on the moment) checkpoint himself. He did great, though!

Fortunately, because of the recent snowstorm, course conditions were excellent, and the weather was gorgeous. Pretty cold in the morning, but rapidly warmed up to the lower 20s by the afternoon. Add to that, since Beargrease, I’m a bit better prepared, equipment-wise, and was able to spend the entire two days comfortably outside.

For the uninitiated, the Birkie-Kortie is two days of cross-country ski races. For amateur-radio purposes, our responsibility is to call in drop-outs to race headquarters, as well as other communication backup tasks.

I highly recommend doing this event. Aside from the obvious fun-factor, it builds radio experience (both operational, and coming up with solutions to communication issues).

More at my forum post [here].