[RFI] Loops for the National RF HFDF Vector Gun

Frank N. Haas KB4T utility.rfi.pro at gmail.com
Sun Jul 10 18:03:54 PDT 2011

A follow-up to my earlier note regarding the subject active loop antenna.

I checked the National RF (NRF) web site and the details on the loop
antennas available for the device is not up to date.

The original version of the Vector Gun came with 3 loop antennas that
covered the spectrum between 8 MHz and 50 MHz. When I ordered my
Vector Gun this year, I was able to purchase a 4th antenna that covers
3.8 MHz  to 8 MHz. I agreed to report to National RF the results of my
work with the 4th antenna. The lowest frequency antenna worked quite
well for me and that's what I reported to NRF.

NRF told me they would modify the antenna offerings to once again
supply 3 antennas but the spectrum coverage would start at 3.8 MHz.
I've heard that since my early success reports with the Vector Gun,
NRF has been doing its best to keep up with the orders. Each kit is
custom made when ordered so there is a delay in actually getting the
package. If anyone on this list has received a Vector Gun kit since
April 2011, perhaps they could advise what antennas came in their kit.

So to summarize:

1.  The National RF HFDF Vector Gun is an effective DFing device for
the high frequencies from 3.8 MHz to 50 MHz provided you use it with a
proper sensitivity-controlled receiver.
2.  There may be a delay of possibly weeks before one's Vector Gun
will ship since each one is usually built when the order comes in.
3.  The effective useful frequency range of the current version of the
Vector Gun is 3.8 to 50 MHz using one of 3 or 4 supplied loop antennas
for the base unit.
4.  The National RF web site is not fully up to date likely because
the small team at NRF is busier than a one-legged man in a
butt-kicking contest building units to fill orders!

Once again, I'll be happy to answer any questions.


Frank N. Haas KB4T
Utility Interference Investigator

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