Fox Hunt Offset Attenuator Kit

Name: Fox Hunt Offset Attenuator Kit
SKU: 14808
Price: 10.00 USD
Availability: OutOfStock
Rating: 5.00 (4 reviews)

(4 Reviews)

Find hidden transmitters (fox) using this offset attenuator

Designed by 3rd Planet Solar / KC9ON in United States of America

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$10.00

Out of Stock

Sold out since Feb 28, 2025

We are no longer shipping outside of the United States via regular postal service.

Find hidden transmitters (fox) using this offset attenuator

What is it? When your closing in on the fox you may find the signals to be strong enough you can no longer find a peak or null with your antenna. Sometimes the signal is so strong that the RF will le…

What is it?

When your closing in on the fox you may find the signals to be strong enough you can no longer find a peak or null with your antenna. Sometimes the signal is so strong that the RF will leak straight into the radio, connections and other equipment making the antenna useless. The solution is to use an offset attenuator. The circuit consists of a small RF generator, in this case 4MHz, which will mix with the incoming fox signal (such as 146.52MHz) and produce new signals at plus and minus the fox signal (142.52Mhz and 150.52Mhz). A potentiometer on the board changes the injection level of the RF generator which in turn attenuates the incoming mixed signal to your radio to a level where tracking can continue.

Why did you make it?

A cost-effective kit to do fox hunting with.

What makes it special?

When used with a [tape measure] beam antenna, you can find transmitter signals down to within inches of the radiated signal.

This is a kit - basic soldering experience is required.

The kit includes a PCB and all parts shown in the picture which mount onto the PCB including the battery connector, power switch, and knob.

The kit does not include an antenna, coax, radio, 9V battery or enclosure.
See the design files section to 3D print an enclosure.

**We are no longer including printed manuals. Please download the manual in the Specs area.****

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Quantity	Price
1-9	$10.00
10-19	$9.00
20+	$8.50

Review Breakdown

Average Ratings

Product: (5.00)

Documentation: (5.00)

Shipping: (5.00)

Communication: (5.00)

Andrew | July 26, 2020

GREAT KIT, WORKS WELL !

Amazingly packaged and labelled kit that assembles quickly and easily. I am using it with a 2 metre tape measure antenna for fox hunting and it is quick and easy to set up and use.

I have used it with success on both the 2 metre band and the 70cm amateur bands.

I enclosed the kit in a diecast metal box - together with its battery and this is mounted on the handle of the antenna. Your antenna should have a good f to b ratio and should incorporate a choke made of a few turns of coax wound round the handle and this is a little insurance that you don't head off in the wrong direction.

Even seconds count in fox hunting and I cannot stress the need to take this kit out and using a fixed station to learn how to use it. Have your radio memories set so you can quickly hop up and down the band in 4 MHz steps and it is a great help that when you do this if you keep to attenuation to a minimum until you have found the correct frequency step.

Congratulations on a very well presented and effective kit.

Andrew ZL2HZ

Justin T. | June 8, 2020

Great product

Great product with crystal clear instructions for the kit assembly. Works great, will order more and recommend to others. 73

Jeremy | Sept. 9, 2019

Excelent kit!

I ordered this kit to use with an upcoming club hunt. The order arrived ahead of schedule! The instructions were clear, the parts came neatly organized! I worked with my 8 year old to put the kit together, great for kids of all ages! A big plus was having the STL files available for printing a case. I printed the case at my local library but ended up using a project enclosure instead. The attenuator was a big it at the hunt, it really allowed me to hone in to the TX when getting closer, other folks struggled with overloaded front ends. Big thank you John!

Gerard | May 6, 2019

Easy to build, works great.

I found the Fox Hunt Attenuator kit an easy and relaxing build. Lack of an enclosure was not a problem but did require some care and head scratching to find the right on and to drill the needed holes. Not a problem but an observation. I will be recommending it to a middle school radio club as a great project for their students. Probably order a couple more soon.

Response from 3rd Planet Solar / KC9ON | May 6, 2019

Thanks for the review. The new V6 kits have an enclosure - still in low volume production due to the enclosure manufacturing steps involved. It's great for kids, I use animal tracking as an example and old hand held scanners (no transmit!). Many schools have 3D printers and a 3D printed enclosure for itandother fox hunting tips can be found here: https://kc9on.com/ham-radio/fox-hunting/
73 John kc9on

$10.00