I wasn't aware that an SMA is not a unique mechanical specification.
Most people seem to be under the impression that it's a quarter-inch
thread and a pin diameter of just under 1 mm.
On 2/5/2019 10:49 AM, cliff palmer wrote:
I tried to order a multimeter test lead that fits SMA connectors so I
can have an easier time testing antennas.
It turns out that "SMA Connector" can mean a lot of different sizes
and types.
Does anyone have the male and female core diameter for the SMA
connectors used by the HackRF One?
Thanks!
On Thu, Jan 31, 2019 at 6:22 PM Michael Ossmann <m...@ossmann.com
<mailto:m...@ossmann.com>> wrote:
Cliff,
That sounds like a faulty ANT500. Please contact your reseller for a
replacement. Send a private email to me and
i...@greatscottgadgets.com <mailto:i...@greatscottgadgets.com>
if you run into any problems with that.
The two most common faults of ANT500 and ANT700 are a short
between the
center pin and shield ground or a break in continuity between the
center
pin and the antenna element. Both of these conditions can be tested
with a continuity tester.
The DC resistance between the center pin and the antenna element is
unspecified, but I think it should be stable and low enough to cause a
continuity tester to beep.
Michael
On Thu, Jan 31, 2019 at 09:45:58AM -0500, cliff palmer wrote:
>
> Jake, the reading between the tip of the antenna and the center
pin varied
> wildly - so much that I borrowed another multi-meter to confirm
them. The
> readings went from zero to 160+ and back. I did secure the
antenna and the
> multi-meter leads to make sure my hands weren't the cause of the
variation.
> It looks like the antenna is faulty.
> Thanks for the hint on CQRX.
>
> I am using the Hackrf with the Ant500 as a starting place to
learn enough
> about SDR to tap RF data feeds from NOAA Buoys. These buoys
measure water
> temp, wind speed and direction, wave direction, height and
frequency. The
> buoy data will be fed into an FPGA/RISC board to calculate and
display
> marine navigation conditions, much like your local weather forecast
> includes a wind speed and direction display.
> There's no way that the Ant500 will be the right antenna for
this. I got
> it because I needed a starting place and a number of YouTube
tutorials on
> SDR used it with the Hackrf. Once I know more about what I am
doing I'll
> be pestering you all again for advice on antennas.
>
> Thanks again
> Cliff
>
> On Wed, Jan 30, 2019 at 11:24 PM Gavin Jacobs
<apriljunk...@hotmail.com <mailto:apriljunk...@hotmail.com>>
> wrote:
>
> > Cliff,
> > I have a hackrf and an Ant500. With the antenna fully
extended, you should
> > measure a very low resistance between the tip of the antenna
and the center
> > pin of the connector. Mine was about 2 ohms. If you have 75
ohms, then
> > there is a problem. Try again between the center pin and the
elbow (where
> > the extensions start) - it should be very low < 1 ohm.
> >
> > You should be able to use GQRX to receive an FM radio station,
with almost
> > any antenna. Most common rookie mistake is forgetting to turn
up the IF
> > gain.
> >
> > Tell us more about your setup and we can help you get started.
> >
> > Jake
> >
> > ------------------------------
> > *From:* HackRF-dev <hackrf-dev-boun...@greatscottgadgets.com
<mailto:hackrf-dev-boun...@greatscottgadgets.com>> on behalf
> > of cliff palmer <palmercl...@gmail.com
<mailto:palmercl...@gmail.com>>
> > *Sent:* January 30, 2019 3:15 PM
> > *To:* hackrf-dev@greatscottgadgets.com
<mailto:hackrf-dev@greatscottgadgets.com>
> > *Subject:* [Hackrf-dev] How to tell if antenna is faulty
> >
> > I have a Hackrf One with an Ant500 Antenna and I am having no
luck with
> > multiple tutorials found on YouTube, including the ones at
Great Scott
> > Gadgets. I measured the resistance on the (disconnected but fully
> > extended) Ant500 Antenna using a multimeter (one lead on the
metal part of
> > the antenna and the other on the male lead in the connector. The
> > multi-meter measured up to 75 Ohm resistance.
> > I'm really new to SDR and so I don't know if resistance should
concern me,
> > but it seems like an antenna should not have resistance.
> > I would appreciate some advice about how to determine if this
is really a
> > problem (and the antenna is faulty) or if I am making a
typical new-to-SDR
> > mistake.
> > Thanks
> > _______________________________________________
> > HackRF-dev mailing list
> > HackRF-dev@greatscottgadgets.com
<mailto:HackRF-dev@greatscottgadgets.com>
> > https://pairlist9.pair.net/mailman/listinfo/hackrf-dev
> >
> _______________________________________________
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> HackRF-dev@greatscottgadgets.com
<mailto:HackRF-dev@greatscottgadgets.com>
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