Hi Mark
In this case the DAV is used for receiving and has a distorted pattern. The loop antenna BTW is wound around a form inside the wooden box. I've checked the inductance/capacitance etc but I suspect the loops location inside the set is poor. My guess is the DF pattern was skewed and probably not very usable even when it was manufactured. BTW it is easier to determine the "Null" on a weak signal if you are just using listening to earphone audio and not using a meter. Been there and done that while flying transports.

BTW The BC-611 DF antenna works great but you have to fabricate a outboard coupler for the antenna.
http://k4che.com/BC611DF/BC611DFpg1.htm

On 11/25/2023 4:57 PM, [email protected] wrote:

I have many years of experience using RDFs and ADFs crewing and later skippering commercial fishing boats. I’ve shot bearings on USCG and FAA beacons, AM BCB stations, other boats on 2-3 MHz AM and weak net buoy beacons operating just near the bottom edge of the 160M ham band. It’s VERY hard to get useable loop antenna directional nulls on weak signals. DAV and BC 611 are not great DF targets. Signal is too weak unless you are very close. Others may hold different opinions but this is my experience.

73

Mark

AF6IM

http://www.arrl.org/files/file/QST/This%20Month%20in%20QST/May2016/GLIFFORT.pdf

On Sat, Nov 25, 2023 at 12:06 PM B. Smith <[email protected]> wrote:

I've worked with the DAV quite a bit. Also worked with Robert Downs on a revised schematic. My only problem with the DAV is using it for DF - I can not get a decent figure 8 pattern. Building a battery box is a week end project.
k4che

On 11/25/2023 11:31 AM, David Stinson wrote:

Is there anyone left who cares about and
actually works with the WWII MAB / DAV,
arguably the Marine Corps version of the BC-611?

73 Dave S.

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