Author: Rick Wagner

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:

AMATEUR RADIO
EMERGENCY
COMMUNICATIONS

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.