VK3YNG Foxhunting equipment and related files
(Updated August 2021)

Transmitter Hunting Links

Other Topics





For general/personal enquiries use this email link. For products use the links below.

1. VHF Sniffer MK4 A ready-to-go processor controlled synthesized auto-ranging foxhunt sniffer covering both 120 and 144MHz bands.

**Out Of Stock!*** Due to extrememely long lead times and a worldwide shortage for many components the MK4 is out of stock for the time being.

If you are in the USA and you want a unit quickly, please contact Bob Miller.

The current version is now 4.2. Functionally this version is similar to V4.1 and V4.0 with a few minor enhancements. Please use this link to request pricing etc. Dont forget to include a delivery address so postage can be accurately calculated.

MK4 Manuals:
pdf Manual for V4.2 - (For v4.2 hardware and v4.2.xx firmware)
     pdf Manual for V4.1 - (For v4.1 hardware and v4.1.xx firmware)
pdf Manual for V4.0 - (For v4.0 hardware and v4.0.xx firmware)
pdf Manual for V3.1 - (For v3.1 hardware and v3.1.xx firmware)
pdf Manual for V3.0 - (For v3.0 hardware and v3.0.xx firmware)
pdf Manual for V2.4 - (For v2.1.25 to 2.1.28 firmware only. Limited release)
pdf Manual for V2.3 - (For v2.1.20 to V2.1.24 firmware only)
pdf Manual for V2.2 - (For V2.3 and V2.4 hardware up to firmware release 2.1.19)
Manuel d'utilisation V2.2  - (French version - Kindly translated by a French amateur who wishes to remain anonymous)
pdf Manual for V2.1 - (For V2.0 and V214 hardware)
pdf Manual for V1.3 -
(For first issue of the MK4 sniffer)
Bigboar trackers Basic manual V2.3 -
(Special dog tracker version - Firmware 2.1.20 or later)
Hunting short duration signals with the MK4 - techniques for hunting short duration pulsed transmitters for animal collars and wildlife.

The UHF version of the MK4 is now sold out. A redesign is planned depending on interest.

2. The Microsniffer is a board level only product for those foxhunting on a budget who don't mind putting in a bit of extra effort. This project has been revised but so far there has been very little interest in it. So the project is currently shelved until I can get enough time to work on it and there is enough interest to complete it. Making it available as a full kit is difficult because of the small size of some of the components and the need for special test equipment. The plan is to produce for use on 2m (144MHz-148MHz) only! Check this link for a feature comparison with the MK4. Please email the author to register interest and I might try to give it some priority...

3. Antennas: The supply of lightweight companion antennas has dried up for the time being. If you want to consider building your own, contact Jack Bramham, VK3WWW for details. There are also a number of good Tape Measure based designs that have been used with this sniffer with great success.

In the USA there are a number of suppliers of suitable antennas:

Arrow Antennas have a number of ready built antennas on a variety of bands suitable for foxhunting.

Bob Miller provides Antennas and DF solutions for both 121.5MHz and 2 meters and usually holds small stocks of the MK4 sniffer for online purchase in the USA.

I am also looking for contacts to pass on for other ready built or kit foxhunting antennas or antenna projects. If you have something along this line that I can add here please email me .

4. 80m Foxhunt Receiver - This project was featured in the  September 2003 issue of Amateur Radio magazine. Kits are now sold out but some specialised parts are still available.

5. Other Foxhunting projects - Includes foxhunting transmitters and details of the old MK3 auto ranging 2m sniffer.

1. The Victorian ARDF Web Site (AUS).
This site has the details on Australian and international ARDF competition events.

2. Joe Moell's foxhunting web site (USA). Contains heaps of useful stuff on foxhunting. This is arguably the best transmitter hunting information site on the net. A must visit!

3. Using the MK4 to hunt an ELT.
This YouTube video by 1st Lt. Joe Tomasone demonstrates using the MK4 to hunt the 121.5MHz homing frequency of an ELT.

4. Ken Harker's Texas ARDF page has some good notes on ARDF transmitter hunting.

5. Chicagoland Foxhunters run hunts in Chicago every week!!.

6. VK3VT Fox Hunt beam article. Probably the most used foxhunt antenna design in Melbourne!

7. Hunting interference sources with the MK4.
VK3TVZ finds interference  on 2m coming from his washing machine!

8. Scout Radio and Electrionics Service Unit. Victorian Branch of Scouts Australia, resource center for JOTA and radio scouting including stations VK3RSR and VK3RSS.

UHF CB (477MHz) MK4 sniffer and antenna:

UHF Sniffer

A number of these have been built for use by cubs and younger scouts.

Gippstech Dish

Articles presented at Gippstech:

A high performance 2m downconverter for fox hunting
This article outlines a high intercept point synthesised and self contained 2m downconverter with a 21.4MHz IF. Presented at Gippstech 2008.

AA battery selection and storage for portable operation
Have you ever wondered if buying some of those "cheap" supermarket batteries is worth it? This article presents the results of nearly 12 months of testing the discharge rates and storage methods for alkaline AA batteries. Article as presented at Gippstech 2006.

Solving noise problems in modern radio systems
Are you doing a project combining digital and sensitive RF circuits? This article presents some considerations based on knowlege gained by the author while doing design work with such systems. This article was presented at Gippstech 2002

Making printed circuit boards at home
Making high quality printed circuits at home is easy using the Kinsten PCB material! This article outlines how to do it. Presented at Gippstech 2001

Simulation tools, real components and limitations
Using free RF simulation tools to get repeatable results for amateur radio projects. Presented at Gippstech 2001

Other reference articles:

Measurements on some RF components
For my own reference!

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