[RFI] MFJ 5008 ultrasonic receiver

Dave Cole dave at nk7z.net
Thu May 19 14:31:52 EDT 2016

On Thu, 2016-05-19 at 12:19 -0400, Frank N. Haas KB4T wrote:
> The percentage of cases where my Radar Engineers Model 250 Ultrasonic
> Detector proves useful is very small.

Which brings up the order of purchase for the aspiring RFI hunter...

For me I purchased items in this order, over a few years....

1.  Mobile rig for hunting, FT-817.
2.  Home made loop.
3.  VHF handheld, which does AM, Kenwood THF6
4.  VHF hand held antenna from MFJ.
5.  Commercial portable loop used, Alex Loop.
6.  Ultrasonic thingy.

Here is the logic...

I can hunt using an FT-817, as it will cover 1.8 through UHF in AM mode
in one radio, and it has a built in battery, and it is sensitive enough
for my use.  Use this on every hunt.

Loop is portable, has a very deep set of nulls, and is easy to handle. I
can take bearings and then draw triangulation maps using the loop in teh
field.  Use this on 99% of the hunts.

Allows me to listen to VHF while listening to HF at the same time.  As I
approach the RFI source, I can start hearing it on VHF AM mode.  TH-F6
because it does AM at V/UHF.  Use this on 90% of the hunts.

Commercial portable loop:
Easy of carry, nothing more...  My 50 buck loop works as good as teh
Alex loop.  It is just not as portable.  99% of the hunts.

Ultrasonic thingy:
I like kits, it was a kit.  I have used it 2 times in the last year.
 Most RFI is NOT arcing power poles.  If it is Power Lines, then the
power company has a better one, and they can do it.  Almost never use

73's, and thanks,
Dave (NK7Z)

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