Generated by All in One SEO v4.9.9, this is an llms.txt file, used by LLMs to index the site.

# KK1L Antenna Switching

 Switches & Band Decoding for Amateur Radio Off the shelf two radio antenna switching options are expensive. I set off to design something for myself that I could also offer to fellow amateur radio operators at a good value. I started with a 2×6 (Two radio by Six Antenna) RF antenna switch and a rudimentary controller and band decoder to indicate which antennas were selected and most importantly keep one radio from transmitting directly into another. My 2×6 RF switching design is in use all over the world. I regularly receive on-the-air comments from fellow hams using my design from world class contest stations to the station you are growing. I have updated the board based on user feedback improving the design, and recently added the 2×8 version as well as building in support for Ethernet/WiFi switching and band decoding. I provide antenna switches with high RF integrity in mind to provide a hard to find component for you to build your station around. Roll your own Raspberry Pi or Microcontroller based decoder. Provide access to the unique PC Boards required for the basis of your antenna switching.

## Sitemaps

- [XML Sitemap](https://kk1l.com/sitemap.xml): Contains all public & indexable URLs for this website.

## Pages

- [KK1L Antenna Switching](https://kk1l.com/) - HF Amateur Radio DIY for contesting antenna switch system SO2R connected two radios 2x6 2x8 band decoder control PCB build your own connect to N1MM+ logging
- [Store](https://kk1l.com/?page_id=1543) - NOTE: If you have any questions I can be reached through the contact form. As a reminder you will need other components to complete your project. Below are some links to help you. I do my best to get your order to you quickly and update the site of any persistent delay (on vacation or
- [Builders Gallery](https://kk1l.com/?page_id=733) - PY1FI M1DST EA2YD F4EJO AB7R I2TKZ K1KD K9CDA OR2F VU2PTT W1CM WA3UTC WC2L K3PA NT1K KK1L
- [Cart](https://kk1l.com/?page_id=1546) - NOTE: I am travelling from May 11th through May 20th. If you place an order it will be fulfilled when I return. I apologize for the inconvenience. I charge for actual shipping and will refund any extra paid. If you have any questions about the cost please contact me.
- [Contact KK1L](https://kk1l.com/?page_id=31) - Please enter the info below and I will get back with you as soon as I can. I usually respond relatively quickly. If you have not heard from me in a day or two, please feel free to reach out again! Don't hesitate to ask questions, make suggestions, or let me know of missing or
- [About KK1L](https://kk1l.com/?page_id=29) - In 2006 I was working to grow my station, but did not have a lot to spend. DIY was the way to go. Off the shelf two radio antenna switching options were (and are!) expensive. I set off to design something for myself that I could also offer to fellow Yankee Clipper Contest Club (YCCC)
- [FreqEZ x16 & FreqEZ x8 by K8UT](https://kk1l.com/?page_id=445) - K8UT became a Silent Key 14-AUG-2024 22-DEC-2025: This great product is now available from KK1L! "Your high tech option" The K8UT FreqEZ Band Decoder is now available from KK1L. It is a combination hardware/software project that provides highly configurable Band Decoding and Remote Antenna selection. For amateurs who use N1MM+, Logger32, UcxLog, Log4OM, or DXLab logging
- [FAQ](https://kk1l.com/?page_id=728) - Head to the Product Summary page for and overview of everything. README - Trouble with Debian TRIXIE FreqEZ Installations!! Folks, If you run into an error where "libcrypto.so.1.1" is not found. Please use this newly compliled version of "freqezrpi" for the lastest version of Raspbian (RPi Debian). Bookworm & Trixie use a different library than
- [Testimonials](https://kk1l.com/?page_id=1968)
- [Account](https://kk1l.com/?page_id=1514)
- [Product Summary](https://kk1l.com/?page_id=30) - amateur radio coaxial antenna switch solutions using manual control, raspberry pi control, udp packet control
- [Terms and Conditions](https://kk1l.com/?page_id=893) - I ship your boards using United States Postal Service (USPS) from Jericho or Essex Jct, Vermont typically using Priority Mail or Priority Mail International. I will use the most cost effective trackable method unless you comment otherwise. I typically can get an order out within a few days. If there is a delay I will
- [Dual Band Decoder / Controller Board](https://kk1l.com/?page_id=252) - "Going Old School" The board includes two band decoders using 4 bit BCD from your radio or logging program. The board can be power directly with 12V DC or 18V P-P AC fed to the rectifier section. I laid the board out such that you can just add the components for the simple version of
- [2x8 Relay Board](https://kk1l.com/?page_id=254) - The relay board is designed to accept sixteen active high (+12V) inputs to select the twelve antenna switching relays. I send +12V to each relay rather than ground each one to make it easier to shield the board. It is impossible to have both radios selecting the same antenna. External logic, if you choose to
- [2x6 Relay Board](https://kk1l.com/?page_id=263) - The relay board is designed to accept twelve active high (+12V) inputs to select the twelve antenna switching relays. I send +12V to each relay rather than ground each one to make it easier to shield the board. It is impossible to have both radios selecting the same antenna. External logic, if you choose to
- [Cookie Policy](https://kk1l.com/?page_id=1587) - This page provides comprehensive information about how we use cookies on our website to enhance your browsing experience, improve website performance, and deliver personalized content. Cookies are small text files that are stored on your device when you visit our site. They help us understand how visitors interact with our website, allowing us to offer

## Store Items

- [Raspberry Pi Zero 2W with header](https://kk1l.com/?ec_store=pageid1543modelnumberpizero2w) - 08-MAY-2026: There is currently a shortage of Pi Zero 2W units everywhere. I will restock when I can. It is possible to use the Pi Zero W to keep the same smaller form factor, but they are not as \"snappy\". I do not stock those.NOT SOLD INDIVIDUALLY. Only sold along with a FreqEZ or Switch Board purchase. My intent is to facilitate construction of your switch project maybe saving you some shipping by carrying a small inventory at cost.Any orders only of Raspberry Pi\'s will be cancelled and payment refunded.
- [FreqEZ HAT16 Antenna Switch Controller by K8UT](https://kk1l.com/?ec_store=freqez-hat16) - FreqEZ HAT16 Antenna Switch Controller by K8UTThe K8UT FreqEZ Band Decoder is a combination hardware/software project that provides highly configurable Band Decoding and Remote Antenna selection. For amateurs who use N1MM+, Logger32, UcxLog, Log4OM, or DXLab logging software, FreqEZ will leverage those programs’ UDP packets for antenna switching. For other amateurs, FreqEZ can connect to the BCD band outputs available from most transceivers. Without available UDP packet or BCD band information, FreqEZ can also be used as a sophisticated manual antenna switch.Available \"assembly required\" for a $5 discount. You solder the provided connectors on yourself for a cost savings and a sense of accomplishment!
- [2x8 Antenna Switch Relay Board](https://kk1l.com/?ec_store=2x8-relay-board) - 2×8 Antenna Switch Relay BoardThis well engineered antenna switch board build with 2oz copper traces provides greater than -61dB port to port isolation, makes it impossible to put both radios on the same antenna port, minimizes reflective coupling. A DIY option not found anywhere else.I provide the option to have unused antennas either open, shorted to ground, or terminated to 50 Ohms. Terminating to 50 Ohms will minimize reflections on the feed lines on unselected ports keeps the interaction from those antennas at a minimum in the switch. It is also sufficient to remove static build up.2oz copper is used on the PCB which can allow 2800W key-down into 50 Ohms the trace heating will be limited to an acceptable 10°C. This also supports 1500W+ at below VSWR of 3. Trace spacing prevents high voltage arc-over as well.The boards are designed with high RF integrity in mind to provide a hard to find DIY component for you to design around. Roll your own Raspberry Pi or Microcontroller based decoder and controller, or use the options I provide.2x8 Chassis Dimension Files (including Excellon drill file)Chassis dimensions in inches PDFChassis dimensions in millimeters PDFChassis Excellon drill file
- [2x6 Antenna Switch Relay Board](https://kk1l.com/?ec_store=2x6-relay-board) - 2×6 Antenna Switch Relay BoardThis well engineered antenna switch board build with 2oz copper traces provides greater than -61dB port to port isolation, makes it impossible to put both radios on the same antenna port, minimizes reflective coupling. A DIY option not found anywhere else.I provide the option to have unused antennas either open, shorted to ground, or terminated to 50 Ohms. Terminating to 50 Ohms will minimize reflections on the feed lines on unselected ports keeps the interaction from those antennas at a minimum in the switch. It is also sufficient to remove static build up.2oz copper is used on the PCB which can allow 2800W key-down into 50 Ohms the trace heating will be limited to an acceptable 10°C. This also supports 1500W+ at below VSWR of 3. Trace spacing prevents high voltage arc-over as well.The boards are designed with high RF integrity in mind to provide a hard to find DIY component for you to design around. Roll your own Raspberry Pi or Microcontroller based decoder and controller, or use the options I provide.2x6 Chassis Dimension Files (including Excellon drill file)Chassis dimensions in inches PDFChassis dimensions in millimeters PDFChassis Excellon drill file
- [Switch Boards](https://kk1l.com/?ec_store=switch-boards)
- [FreqEZ HATs](https://kk1l.com/?ec_store=freqez-hats)
- [Upgrade from HAT8 to HAT16](https://kk1l.com/?ec_store=upgrade-from-hat8-to-hat16) - Available for customers to upgrade to HAT16 if wrong order for HAT8 was placed.
- [FreqEZ HAT8 Antenna Switch Controller by K8UT](https://kk1l.com/?ec_store=freqez-hat8) - FreqEZ HAT8 Antenna Switch Controller by K8UTThe K8UT FreqEZ Band Decoder is a combination hardware/software project that provides highly configurable Band Decoding and Remote Antenna selection. For amateurs who use N1MM+, Logger32, UcxLog, Log4OM, or DXLab logging software, FreqEZ will leverage those programs’ UDP packets for antenna switching. For other amateurs, FreqEZ can connect to the BCD band outputs available from most transceivers. Without available UDP packet or BCD band information, FreqEZ can also be used as a sophisticated manual antenna switch.NOTE: TWO of these are required to fully control a 2x6 or 2x8 switch. A single unit is fine to run the switch as a 1x6 or 1x8. One Raspberry Pi is needed per HAT. See an example of my use of 2 HAT8\'s here.Available \"assembly required\" for a $5 discount. You solder the provided connectors on yourself for a cost savings and a sense of accomplishment!
- [Dual Band-Decoder/Controller Board](https://kk1l.com/?ec_store=dual-band-decoder-controller-board) - Dual Band-Decoder / Controller BoardThe board includes two band decoders using 4 bit BCD from your radio or logging program. The board can be power directly with 12V DC or 18V P-P AC fed to the rectifier section. I laid the board out such that you can just add the components for the simple version of the controller, if you don’t need the band decoders for example. The band decode segment includes an option to lockout antenna switching while transmitting. If you do not need the PTT controlled lockout you can leave that segment out as well. These sections are clearly marked on the PC board and in the assembly documentation.Supports only 2×6 antenna switch boardThe board is laid out modularly as several independent circuits on the same board which are easily integratedOne basic 2×6 antenna switch controller where active high Rotary A/B as inputs drive active high relay connections as outputsTwo band decoders where active high BAND-A/B BCD inputs drive active high J15/J16 band decode outputsBy connecting the band decode outputs to the rotary inputs you create a computer controlled 2×6 switchOptically isolated PTT lockoutAC to DC converter sectionProtection for hot switching when using the BCD inputs.When PTT is GND the current antenna selections will be held until PTT is deassertedThere is no hot switch protection for the manual active high switch inputsOnly one radio can use an antenna port at a timeNo stealing! The first radio keeps the antenna until releasedLED indicates when antenna(s) is selected for each radioBCD band decoder supportOpto-isolator inputs for each radio port using the “standard” W9XT, NA, TRLog formatTo wire the six contest band just short across from J15/J16 to the corresponding switchOnly one radio port selectable per antenna. The first one to have the antenna keeps it until released.Can use rotary, toggle, or latched push button switches. Latched push button or toggle allow for multiple antennas per radio port (for stacking).The inputs are +12V active high logic and float when not selected.You might consider a 7 position rotary switch if also using the BCD inputs. This will allow for a “no select” position for the rig or computer to control the selections.Along with manual switching you can use BCD band data from your radio or logging program. The decoding follows the “standard” of NA, TRLog, and others.To wire the six contest band just short across from J15/J16 to the corresponding switch connections.You can also “wire OR” bands to one port.For example to put a tri-bander on Port5 you can connect the 10, 15, and 20m decoded outputs to the port 5 switch position.The inputs are optically isolated and convert from 5V or 12V active high logic to relay (12V) levels.CMOS devices (4028, 4011) take +12V VCC directly.Quad optoisolators convert external 5V/12V interface to +12V.
- [RaspberryPi](https://kk1l.com/?ec_store=raspberrypi)
- [K8UT FreqEZ](https://kk1l.com/?ec_store=k8ut-freqez)
- [KK1L Contest Gear](https://kk1l.com/?ec_store=kk1l-contest-gear)

## Tags

- [manufacturer](https://kk1l.com/?tag=manufacturer)
- [product](https://kk1l.com/?tag=product)
- [category](https://kk1l.com/?tag=category)
- [FreqEZ HATs](https://kk1l.com/?tag=freqez-hats)
- [Switch Boards](https://kk1l.com/?tag=switch-boards)

## Pattern Type

- [pattern](https://kk1l.com/?coblocks_pattern_type=pattern)

## Pattern Category

- [buttons](https://kk1l.com/?coblocks_pattern_category=buttons)