Technically there is only *one* SMA connector, it is defined in MIL-STD-348. There is also "RP-SMA" which has the same mechanical dimensions but swaps the pin and socket locations from the outer threaded version to the inner threaded version.
That said, a vendor might confuse them and call some random connector "SMA" (I have seen TV types refer to the 75 ohm "F" connector as an SMA connector incorrectly) --Chuck On Tue, Feb 5, 2019 at 8:53 AM cliff palmer <palmercl...@gmail.com> 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> 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 >> 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 >> > >> > 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> on >> behalf >> > > of cliff palmer <palmercl...@gmail.com> >> > > *Sent:* January 30, 2019 3:15 PM >> > > *To:* 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 >> > > https://pairlist9.pair.net/mailman/listinfo/hackrf-dev >> > > >> >> > _______________________________________________ >> > HackRF-dev mailing list >> > HackRF-dev@greatscottgadgets.com >> > https://pairlist9.pair.net/mailman/listinfo/hackrf-dev >> >> _______________________________________________ > HackRF-dev mailing list > HackRF-dev@greatscottgadgets.com > https://pairlist9.pair.net/mailman/listinfo/hackrf-dev >
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