Awesome! I think a reasonable first step would be for everyone to buy RFM23BP modules, try them out, and gather knowledge. Or other modules that are compatible on paper, so we can test compatibility early.
On May 26, 2014, at 12:52, Norm Sutaria <[email protected]> wrote: > I'd also like to participate in this project - it sounds awesome! > > Norm > KB2JRP > > > On Fri, May 23, 2014 at 8:35 PM, <[email protected]> wrote: > Send Radio mailing list submissions to > [email protected] > > To subscribe or unsubscribe via the World Wide Web, visit > https://list.hackmanhattan.com/listinfo/radio > or, via email, send a message with subject or body 'help' to > [email protected] > > You can reach the person managing the list at > [email protected] > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of Radio digest..." > > > Today's Topics: > > 1. 70cm GFSK project (Guan Yang) > 2. Re: 70cm GFSK project (Robert O'Connor) > 3. Re: 70cm GFSK project (David Reeves) > 4. Re: 70cm GFSK project (Max Nager) > 5. Re: 70cm GFSK project (Guan Yang) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Fri, 23 May 2014 17:48:27 -0400 > From: Guan Yang <[email protected]> > To: Hack Manhattan Amateur Radio Club <[email protected]> > Subject: [hmradio] 70cm GFSK project > Message-ID: <[email protected]> > Content-Type: text/plain; charset=us-ascii > > I've been talking to a few of you about a project to finally make it easy to > do great digital on 2 meter or 70 cm. The use case is both emergency > communications, based on our frustrations with FM voice and our needs in the > Rockaways during Sandy, and APRS and similar modes, based on our frustration > with AFSK over FM in Manhattan. > > Right now I've ordered some RFM23BP transceiver modules, which can operate on > the entire 70cm amateur band and also 433 MHz ISM. The plan is to do 9600 bps > GFSK, and to test for compatibility with other chips, for example ADF7023 > from Analog. There's also a similar part from Silicon Labs. > > RFM23BP is easier to get started with since it has a single ended 50 ohm RF > output. It can't quite do GMSK with typical bit rates because deviation has > to be a multiple of 625 Hz. I'm thinking we might try 9600 bps with 2500 Hz > deviation. (That's carrier to peak, not peak to peak. I think.) > > The final product might be a circuit board with USB serial, possibly > Bluetooth LE for communication with phones, a battery charging IC, and a > lithium ion battery. > > ------------------------------ > > Message: 2 > Date: Fri, 23 May 2014 17:49:22 -0400 > From: "Robert O'Connor" <[email protected]> > To: Hack Manhattan Amateur Radio Club <[email protected]> > Subject: Re: [hmradio] 70cm GFSK project > Message-ID: > <CAPncwvJE1m3ho8LG3tEFd=q4ekhm72mzqgbk2o60hskbgtc...@mail.gmail.com> > Content-Type: text/plain; charset="utf-8" > > I'd be down > > --Rob > Sent from my phone...excuse any typos please! > On May 23, 2014 5:48 PM, "Guan Yang" <[email protected]> wrote: > > > I've been talking to a few of you about a project to finally make it easy > > to do great digital on 2 meter or 70 cm. The use case is both emergency > > communications, based on our frustrations with FM voice and our needs in > > the Rockaways during Sandy, and APRS and similar modes, based on our > > frustration with AFSK over FM in Manhattan. > > > > Right now I've ordered some RFM23BP transceiver modules, which can operate > > on the entire 70cm amateur band and also 433 MHz ISM. The plan is to do > > 9600 bps GFSK, and to test for compatibility with other chips, for example > > ADF7023 from Analog. There's also a similar part from Silicon Labs. > > > > RFM23BP is easier to get started with since it has a single ended 50 ohm > > RF output. It can't quite do GMSK with typical bit rates because deviation > > has to be a multiple of 625 Hz. I'm thinking we might try 9600 bps with > > 2500 Hz deviation. (That's carrier to peak, not peak to peak. I think.) > > > > The final product might be a circuit board with USB serial, possibly > > Bluetooth LE for communication with phones, a battery charging IC, and a > > lithium ion battery. > > _______________________________________________ > > Radio mailing list [email protected] > > https://list.hackmanhattan.com/listinfo/radio > > > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: > <https://list.hackmanhattan.com/pipermail/radio/attachments/20140523/22ada61a/attachment-0001.html> > > ------------------------------ > > Message: 3 > Date: Fri, 23 May 2014 20:10:11 -0400 > From: David Reeves <[email protected]> > To: Hack Manhattan Amateur Radio Club <[email protected]> > Subject: Re: [hmradio] 70cm GFSK project > Message-ID: > <capvsgtxkwrievqt4tzsw9kysqaofxqtdt62t9rxuxpw-ock...@mail.gmail.com> > Content-Type: text/plain; charset="utf-8" > > Ok, so is the reasoning here that some kind of direct FSK modulation will > suffer fewer of the propagation difficulties that we've seen with reception > of voice/AFSK? > > I'd assume this would be simplex only, which has in fact been by far the > most reliable over the few small-area (< 3 miles) urban nets I attended > recently. If we could get up to a 10 mile range somehow with some clever > digital processing, I'd think that would be very useful indeed for us > canyon-dwellers - do you think that might be possible? > > > > > On Fri, May 23, 2014 at 5:48 PM, Guan Yang <[email protected]> wrote: > > > I've been talking to a few of you about a project to finally make it easy > > to do great digital on 2 meter or 70 cm. The use case is both emergency > > communications, based on our frustrations with FM voice and our needs in > > the Rockaways during Sandy, and APRS and similar modes, based on our > > frustration with AFSK over FM in Manhattan. > > > > Right now I've ordered some RFM23BP transceiver modules, which can operate > > on the entire 70cm amateur band and also 433 MHz ISM. The plan is to do > > 9600 bps GFSK, and to test for compatibility with other chips, for example > > ADF7023 from Analog. There's also a similar part from Silicon Labs. > > > > RFM23BP is easier to get started with since it has a single ended 50 ohm > > RF output. It can't quite do GMSK with typical bit rates because deviation > > has to be a multiple of 625 Hz. I'm thinking we might try 9600 bps with > > 2500 Hz deviation. (That's carrier to peak, not peak to peak. I think.) > > > > The final product might be a circuit board with USB serial, possibly > > Bluetooth LE for communication with phones, a battery charging IC, and a > > lithium ion battery. > > _______________________________________________ > > Radio mailing list [email protected] > > https://list.hackmanhattan.com/listinfo/radio > > > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: > <https://list.hackmanhattan.com/pipermail/radio/attachments/20140523/9a47feab/attachment-0001.html> > > ------------------------------ > > Message: 4 > Date: Fri, 23 May 2014 20:18:39 -0400 > From: Max Nager <[email protected]> > To: Hack Manhattan Amateur Radio Club <[email protected]> > Subject: Re: [hmradio] 70cm GFSK project > Message-ID: <[email protected]> > Content-Type: text/plain; charset="us-ascii" > > Ditto. Sounds awesome. > > Max > > > On May 23, 2014, at 5:49 PM, "Robert O'Connor" <[email protected]> > > wrote: > > > > I'd be down > > > > --Rob > > Sent from my phone...excuse any typos please! > > > >> On May 23, 2014 5:48 PM, "Guan Yang" <[email protected]> wrote: > >> I've been talking to a few of you about a project to finally make it easy > >> to do great digital on 2 meter or 70 cm. The use case is both emergency > >> communications, based on our frustrations with FM voice and our needs in > >> the Rockaways during Sandy, and APRS and similar modes, based on our > >> frustration with AFSK over FM in Manhattan. > >> > >> Right now I've ordered some RFM23BP transceiver modules, which can operate > >> on the entire 70cm amateur band and also 433 MHz ISM. The plan is to do > >> 9600 bps GFSK, and to test for compatibility with other chips, for example > >> ADF7023 from Analog. There's also a similar part from Silicon Labs. > >> > >> RFM23BP is easier to get started with since it has a single ended 50 ohm > >> RF output. It can't quite do GMSK with typical bit rates because deviation > >> has to be a multiple of 625 Hz. I'm thinking we might try 9600 bps with > >> 2500 Hz deviation. (That's carrier to peak, not peak to peak. I think.) > >> > >> The final product might be a circuit board with USB serial, possibly > >> Bluetooth LE for communication with phones, a battery charging IC, and a > >> lithium ion battery. > >> _______________________________________________ > >> Radio mailing list [email protected] > >> https://list.hackmanhattan.com/listinfo/radio > > _______________________________________________ > > Radio mailing list [email protected] > > https://list.hackmanhattan.com/listinfo/radio > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: > <https://list.hackmanhattan.com/pipermail/radio/attachments/20140523/f90fea11/attachment-0001.html> > > ------------------------------ > > Message: 5 > Date: Fri, 23 May 2014 20:34:45 -0400 > From: Guan Yang <[email protected]> > To: [email protected] > Subject: Re: [hmradio] 70cm GFSK project > Message-ID: > <[email protected]> > Content-Type: text/plain > > On Fri, May 23, 2014, at 20:10, David Reeves wrote: > > Ok, so is the reasoning here that some kind of direct FSK modulation will > > suffer fewer of the propagation difficulties that we've seen with > > reception > > of voice/AFSK? > > Yes; certainly on a per-baud basis. I've found that a lot of the time > under bad propagation situations you can actually hear voices if you > open the squelch. Something not mediated by the FM voice thing should be > better. > > RFM23BP has a best case RX sensitivity of -120dBm, which is well below > the noise floor at these frequencies. Of course we will have to test it. > But even if propagation is just as terrible as FM voice, it will be > easier to copy a digital transmission because we can do aggressive > forward error correction and easily repeat transmissions many times. > > It's frustrating to be able to hear that there's *some* voice without > understanding the words. Also talking to people is horrible even under > ideal circumstances. > > > I'd assume this would be simplex only, which has in fact been by far the > > most reliable over the few small-area (< 3 miles) urban nets I attended > > recently. If we could get up to a 10 mile range somehow with some clever > > digital processing, I'd think that would be very useful indeed for us > > canyon-dwellers - do you think that might be possible? > > We could have digipeaters. That alone would help a lot. A 2m or 70cm FM > voice repeater is a big hassle to move around and set up. With a $50 > digipeater we could just plant them in various locations in the field > and cross our fingers that they won't get stolen - and it won't be a > huge deal if they are. > > > ------------------------------ > > Subject: Digest Footer > > _______________________________________________ > Radio mailing list > [email protected] > https://list.hackmanhattan.com/listinfo/radio > > > ------------------------------ > > End of Radio Digest, Vol 11, Issue 13 > ************************************* > > > > -- > Norm Sutaria > (646)580-9749 > [email protected] > _______________________________________________ > Radio mailing list [email protected] > https://list.hackmanhattan.com/listinfo/radio
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