glewis@cit-vax.Caltech.Edu (Glenn M. Lewis) (10/09/87)
I am designing an RS-232 9600 baud radio link. I need information on how to build a relatively high power (~1 mile distance) transmitter / receiver link. All I really need is the information on how to boost my RF signal up to acceptable levels to transmit, and then how to filter out that frequency. I will probably use an RF frequency near 27MHz, so as to make the FCC happy. Do any of you electronics Wizards have reference books that give me schematics, or could you yourselves help me out? I would very much appreciate it. Heck, maybe someone else would be interested in the complete schematics once the things works??? Thank you. -- Glenn Lewis -- glewis@cit-vax.caltech.edu
parnass@ihuxz.ATT.COM (Bob Parnass, AJ9S) (10/10/87)
In article <4167@cit-vax.Caltech.Edu>, glewis@cit-vax.Caltech.Edu (Glenn M. Lewis) writes: > I am designing an RS-232 9600 baud radio link. I need information > on how to build a relatively high power (~1 mile distance) transmitter / > receiver link. All I really need is the information on how to boost my RF > signal up to acceptable levels to transmit, and then how to filter out that > frequency. I will probably use an RF frequency near 27MHz, so as to make the > FCC happy. This will not "make the FCC happy." Digital emissions are not permitted in the Citizens Radio Service. Get a industrial radio license (possibly with an allocation in the 72 or 900 MHz range) and do it right. -- ===-===-===-===-===-===-===-===-===-===-===-===-===-===-===-===-===-===-===-=== Bob Parnass, Bell Telephone Laboratories - ihnp4!ihuxz!parnass - (312)979-5414
richard@islenet.UUCP (Richard Foulk) (10/11/87)
In article <2346@ihuxz.ATT.COM> parnass@ihuxz.ATT.COM (Bob Parnass, AJ9S) writes: > In article <4167@cit-vax.Caltech.Edu>, glewis@cit-vax.Caltech.Edu (Glenn M. Lewis) writes: > > > I am designing an RS-232 9600 baud radio link. I need information > > on how to build a relatively high power (~1 mile distance) transmitter / > > receiver link. All I really need is the information on how to boost my RF > > signal up to acceptable levels to transmit, and then how to filter out that > > frequency. I will probably use an RF frequency near 27MHz, so as to make the > > FCC happy. > > This will not "make the FCC happy." > Digital emissions are not permitted in the Citizens Radio Service. > > Get a industrial radio license (possibly with an allocation in > the 72 or 900 MHz range) and do it right. > It appears that you may be able to buy such a device soon. In the September 21st issue of Infoworld they had a short article on page 14 entitled "Wireless LAN Communicates At 19.2 KBPS Within 300 feet". The unit was developed jointly by Technology Development of Spokane, Washington, and Ray-Net Communication Systems Inc. of Vancouver, BC. Quoting from the article: "Ray-LAN uses Novell Netware-compatible software and includes an adapter card and independent, video-cassette-size RF transceiver for each computer. Inside a building, computers within 300 feet of each other communicate at 72 MHz at speeds up to 19.2 kilobits per second." It's to be available Q1 of '88. And supposedly the system will allow a user to work from home "at distances up to five miles given proper conditions". FCC licensing is supposed to be a one-time deal for a whole network. Ray-Net Communication Systems, Inc. E. 12806 Nora Ave. Spokane, WA 99216 (509) 924-2855 Looked kind of interesting to me... Richard Foulk ...{dual,vortex,ihnp4}!islenet!richard Honolulu, Hawaii -- Richard Foulk ...{dual,vortex,ihnp4}!islenet!richard Honolulu, Hawaii
henry@utzoo.UUCP (Henry Spencer) (10/15/87)
> Digital emissions are not permitted in the Citizens Radio Service.
Furthermore, if I am not mistaken, one condition of no-license use of the
Citizens Radio Service is that equipment be type-approved by the FCC. In
other words, you can't build your own.
--
"Mir" means "peace", as in | Henry Spencer @ U of Toronto Zoology
"the war is over; we've won". | {allegra,ihnp4,decvax,utai}!utzoo!henryglewis@cit-vax.Caltech.Edu (Glenn M. Lewis) (10/17/87)
In article <8775@utzoo.UUCP> henry@utzoo.UUCP (Henry Spencer) writes: >> Digital emissions are not permitted in the Citizens Radio Service. > >Furthermore, if I am not mistaken, one condition of no-license use of the >Citizens Radio Service is that equipment be type-approved by the FCC. In >other words, you can't build your own. Oh well. Thank you all for your help. -- Glenn -- glewis@cit-vaxWBWBWw ofincl
richard@islenet.UUCP (Richard Foulk) (10/19/87)
In article <8775@utzoo.UUCP> henry@utzoo.UUCP (Henry Spencer) writes: > > Digital emissions are not permitted in the Citizens Radio Service. > > Furthermore, if I am not mistaken, one condition of no-license use of the > Citizens Radio Service is that equipment be type-approved by the FCC. In > other words, you can't build your own. That's not what I heard. Forrest Mims had a pretty complete theory and construction article in Modern Electronics a while back. He mentioned nothing about type-approval or the exclusion of digital emissions. If I can find the article I'll fill in some more detail. Does anyone else have solid info? -- Richard Foulk ...{dual,vortex,ihnp4}!islenet!richard Honolulu, Hawaii
noise@eneevax.UUCP (Johnson Noise) (10/22/87)
I'm not so sure about not sending digital on 27 or 49MHz is necessarily illegal. Random radio controlled cars use these freq- uencies all the time and the signals are more or less "digital". I think that the FCC is more concerned with bandwidth. 9600 baud is out of the question, but I'm sure you could get away with 300, maybe even 1200. If you were to apply a suitable low pass characteristic to your signal, who would know you weren't playing with an RC? It ain't a crime 'til you get caught.
bill@trotter.usma.edu (Bill Gunshannon) (10/22/87)
In article <3578@islenet.UUCP>, richard@islenet.UUCP (Richard Foulk) writes: > In article <8775@utzoo.UUCP> henry@utzoo.UUCP (Henry Spencer) writes: > > > Digital emissions are not permitted in the Citizens Radio Service. You are also still required to identify with the FCC assigned callsign which they no longer issue. Off hand I would say that they don't really care what you do on CB. bill gunshannon UUCP: {philabs}\ US SNAIL: Martin Marietta Data Systems {phri } >!trotter.usma.edu!bill USMA, Bldg 600, Room 26 {sunybcs}/ West Point, NY 10996 RADIO: KB3YV PHONE: WORK (914)446-7747 AX.25: KB3YV @ K3RLI PHONE: HOME (914)565-5256
bill@trotter.usma.edu (Bill Gunshannon) (10/22/87)
OOPS, your milage may vary if you are north of the St. Lawrence where the
rules are different. (Sorry Henry) :-)
bill gunshannon
UUCP: {philabs}\ US SNAIL: Martin Marietta Data Systems
{phri } >!trotter.usma.edu!bill USMA, Bldg 600, Room 26
{sunybcs}/ West Point, NY 10996
RADIO: KB3YV PHONE: WORK (914)446-7747
AX.25: KB3YV @ K3RLI PHONE: HOME (914)565-5256