[aprssig] Current path
Rodge Jones g0cjm at live.comTue Mar 9 14:08:26 UTC 2010
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Current mobile/fixed paths are as follows allowing for excellent Igate and Digi. Path: APRS,WIDE*,WIDE6-6: sometimes here i try out CQ,ARISS* but with little success. Very best wishes/Tres meilleurs sentiments, Rodge Rodge E. JONES G0CJM G6XCJ [g0cjm at live.com] 07928-252-090 [or] 07805-85-44-26* *NOT available outside Britain. Path outside Britain: CQ,ARISS* (Simplex 145.825Mhz) radio location: www.aprs.fi/g0cjm-9 (sometimes -12) Prof. R.E.JONES PJM(1962)HMAF(Vtn) Physics & Solar-flux. Je parle francais et Chinois de Canton. I am a linguist in SIX languages. these include Cantonese and Malay. Due to war firefight both legs are amputated and hearing lost (Borneo 1962). Life-Member:RMPA. Member:CTS.,RGJRA.,G-QRP.,OCA43rd & 52nd.,BRARS. Private & Confidential to addressee. DPA 1998 HRA 1998 R S V P !! > From: aprssig-request at tapr.org > Subject: aprssig Digest, Vol 69, Issue 9 > To: aprssig at tapr.org > Date: Tue, 9 Mar 2010 12:00:02 +0000 > > Send aprssig mailing list submissions to > aprssig at tapr.org > > To subscribe or unsubscribe via the World Wide Web, visit > https://www.tapr.org/cgi-bin/mailman/listinfo/aprssig > or, via email, send a message with subject or body 'help' to > aprssig-request at tapr.org > > You can reach the person managing the list at > aprssig-owner at tapr.org > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of aprssig digest..." > > > Today's Topics: > > 1. Re: Color Display (Shawn Stoddard) > 2. Re: APRS Messenger PSK-63 On The Air Reports -- Magnetic Loop > Antenna Now Up (Stephen H. Smith) > 3. Re: APRS Messenger PSK-63 On The Air Reports -- Magnetic Loop > Antenna Now Up (Lynn W. Deffenbaugh (Mr)) > 4. Re: APRS Messenger PSK-63 On The Air Reports -- Magnetic Loop > Antenna Now Up (Stephen H. Smith) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Mon, 8 Mar 2010 08:28:57 -0500 > From: Shawn Stoddard <stoddard at pobox.com> > Subject: Re: [aprssig] Color Display > To: TAPR APRS Mailing List <aprssig at tapr.org> > Message-ID: <20100308132907.894EB94955 at b-sasl-quonix.pobox.com> > Content-Type: text/plain; charset="iso-8859-1" > > This is research for a new piece of software. I recall having seen something on aprs.org regarding how tro display the icon for station to show more than location. I'll keep digging. > > > -----Original Message----- > From: Curt, WE7U <curt.we7u at gmail.com> > Sent: Sunday, March 07, 2010 11:04 PM > To: TAPR APRS Mailing List <aprssig at tapr.org> > Subject: Re: [aprssig] Color Display > > On Sun, 7 Mar 2010, Lynn W. Deffenbaugh (Mr) wrote: > > > Shawn Stoddard wrote: > >> I recall seeing something about the color of a station indicating how > >> recently it has been heard from. Anybody know where I might have seen this? > > > > It would help to know what APRS software you are referring to with this > > question. The display of a station, particularly its color, is up to the > > software and not part of the APRS protocol spec itself, although Bob > > Bruninga's APRSdos had some color coding that it did, but I don't believe it > > was based on age, but on capabilities. > > Xastir has a mode: "Display last report age", which displays minutes > since the station was last heard. That text starts out green, > changes to yellow after some number, then red some minutes after > that. The intent was to help check up on SAR personnel more often > via voice-checks if they weren't being heard from on APRS. If the > age goes yellow, call then on voice. If it goes red, perhaps have > another team check on them. > > -- > Curt, WE7U. <http://www.eskimo.com/~archer> > APRS: Where it's at! <http://www.xastir.org> > Lotto: A tax on people who are bad at math. - unknown > Windows: Microsoft's tax on computer illiterates. - WE7U. > The world DOES revolve around me: I picked the coordinate system!" > > _______________________________________________ > aprssig mailing list > aprssig at tapr.org > https://www.tapr.org/cgi-bin/mailman/listinfo/aprssig > > > > > > ------------------------------ > > Message: 2 > Date: Mon, 08 Mar 2010 14:41:51 -0800 > From: "Stephen H. Smith" <wa8lmf2 at aol.com> > Subject: Re: [aprssig] APRS Messenger PSK-63 On The Air Reports -- > Magnetic Loop Antenna Now Up > To: TAPR APRS Mailing List <aprssig at tapr.org> > Message-ID: <4B957D2F.3060106 at aol.com> > Content-Type: text/plain; charset=ISO-8859-1; format=flowed > > [ 14:30 Pacific Time (02:27 UTC) Monday 8 Mar] > > I have successfully built, tuned and erected a homebrew magnetic loop > antenna this afternoon. I now have this antenna connected to the > TS-50 that is monitoring 10.149 APRS (Both AX.25 FSK and PSK63). > This replaces the homebrew vertical dipole made from two 30M mobile > HamSticks that I have been using up til now. The HF all-us map > display on my web server at: > > <http://wa8lmf.dyndns.org:14439> > > is now using the new loop antenna. > > The first thing I noticed is that the natural background hiss and "band > noise" heard with the new antenna dropped about 1 S-unit compared to the > dipole. However, the TV sync hash from a leaking cable TV trunk, and > AC hum and buzz that I was hearing on the dipole has completely > disappeared. I appear to have a far higher signal-to-noise ratio than > before. > > I expect that the small (1 meter diameter) resonant loop will have far > better high-angle reception than the vertical dipole. I should be able > to hear stations up and down the west coast (i.e. a relatively short > haul of 400-1000 miles) much better. > > Eagerly awaiting the stations from the midwest and east coast that > normally start showing up about 16:00 local time. > > Details on this dirt-cheap easy-to-build compact antenna for 30 meters > (that could be stealthed in an attic) will follow in a week or so. > > ------------------------------------------------------------------------ > > -- > > Stephen H. Smith wa8lmf (at) aol.com > EchoLink Node: WA8LMF or 14400 [Think bottom of the 2M band] > Skype: WA8LMF > Home Page: http://wa8lmf.net > > NEW! Universal HF/VHF/UHF Antenna Mounting System > http://wa8lmf.net/mobile/UniversalAntMountSystem.htm > > "APRS 101" Explanation of APRS Path Selection & Digipeating > http://wa8lmf.net/DigiPaths > > Updated "Rev H" APRS http://wa8lmf.net/aprs > Symbols Set for UI-View, > UIpoint and APRSplus: > > > > > > ------------------------------ > > Message: 3 > Date: Mon, 08 Mar 2010 17:53:27 -0500 > From: "Lynn W. Deffenbaugh (Mr)" <ldeffenb at homeside.to> > Subject: Re: [aprssig] APRS Messenger PSK-63 On The Air Reports -- > Magnetic Loop Antenna Now Up > To: TAPR APRS Mailing List <aprssig at tapr.org> > Message-ID: <4B957FE7.2020003 at homeside.to> > Content-Type: text/plain; charset=ISO-8859-1; format=flowed > > Stephen H. Smith wrote: > > Eagerly awaiting the stations from the midwest and east coast that > > normally start showing up about 16:00 local time. > > Details on this dirt-cheap easy-to-build compact antenna for 30 > > meters (that could be stealthed in an attic) will follow in a week or so. > > And I'm eagerly awaiting the antenna details! I just posted a request > for 30m antenna suggestions to another group and received some > suggestions, but I'm looking to go cheap, dirt-cheap is even better! > Any early hints or links so I can start to get a handle on what to > expect? Even if it's a reference to a page number or article title at > arrl.net or the 2010 Handbook, I'm all eyes! > > Lynn (D) - KJ4ERJ-1 - IGating 10.147.600 both AX.25 and PSK-63 from Palm > Bay, FL USA (EL97qx) > > PS. See http://tinyurl.com/IGATE-KJ4ERJ-1 for recently heard stations > > > > > > ------------------------------ > > Message: 4 > Date: Mon, 08 Mar 2010 16:01:10 -0800 > From: "Stephen H. Smith" <wa8lmf2 at aol.com> > Subject: Re: [aprssig] APRS Messenger PSK-63 On The Air Reports -- > Magnetic Loop Antenna Now Up > To: TAPR APRS Mailing List <aprssig at tapr.org> > Message-ID: <4B958FC6.3080506 at aol.com> > Content-Type: text/plain; charset=ISO-8859-1; format=flowed > > Lynn W. Deffenbaugh (Mr) wrote: > > Stephen H. Smith wrote: > >> Eagerly awaiting the stations from the midwest and east coast that > >> normally start showing up about 16:00 local time. Details on this > >> dirt-cheap easy-to-build compact antenna for 30 meters (that could > >> be stealthed in an attic) will follow in a week or so. > > > > And I'm eagerly awaiting the antenna details! I just posted a request > > for 30m antenna suggestions to another group and received some > > suggestions, but I'm looking to go cheap, dirt-cheap is even better! > > Any early hints or links so I can start to get a handle on what to > > expect? Even if it's a reference to a page number or article title at > > arrl.net or the 2010 Handbook, I'm all eyes! > > > > Lynn (D) - KJ4ERJ-1 - IGating 10.147.600 both AX.25 and PSK-63 from > > Palm Bay, FL USA (EL97qx) > > > > PS. See http://tinyurl.com/IGATE-KJ4ERJ-1 for recently heard stations > > > > > > > > _______________________________________________ > > aprssig mailing list > > aprssig at tapr.org > > https://www.tapr.org/cgi-bin/mailman/listinfo/aprssig > > I'd do a web page on it now, but I'm getting ready for the IWCE > (International Wireless Communications Expo) in Las Vegas this week. > > > Basically, a "magnetic loop" antenna is a very small (relative to > wavelength) single-turn loop tuned to resonance with a series > capacitor. A second, much smaller loop connected directly to a coax > feed line is placed inside the larger loop, nearly tangent to the first > loop at the side opposite the capacitor. This small loop forms the > primary winding of an air-core RF transformer with the larger loop > forming the secondary winding > > > Such a device can be nearly as efficient on transmit as a full-sized > dipole -IF- the loop and capacitor are very efficient and low loss. > The MFJ "Super-HI-Q Loop" antenna and the old AEA "IsoLoop" are > commercial versions of such an antenna that are tunable between 10 to 30 > MHz. With a 100 watt transmitter, HUNDREDS of RF amps circulate in the > loop and 4,000-to-10,000 volts can appear across the capacitor. > > > My loop is constructed of 3/8" soft copper "refrigeration tubing" from > Home Depot. Ten feet of this are bent into a circular loop about 1 > yard in diameter. The support is a vertical mast made from a piece > of 1" Sched 40 PVC water pipe. with two 3/8" holes drilled through it's > diameter about 37" apart. > > > The trick was the capacitor. Normally, mag loop ants use motorized > high-voltage butterfly, split-stator variable caps or variable vacuum > caps to tune the loop to resonance while withstanding very high RF > voltages. (I.e. the kind of variable caps you see in high power antenna > tuners.) Since I didn't need the antenna to be tunable (it's going to > set to a single spot frequency (10.149 MHz) permanently, I calculated > the required capacitance and set out to create a cheap fixed-value cap > with 4-5 KV breakdown. > > > The inside diameter of the 3/8" tubing is an EXACT fit for the center > conductor and dielectric of RG-8 or RG-213 coax. I stripped the outer > jacket and braid off 37" of RG-213 cable and then stripped the > dielectric off half an inch of the remaining insulated center > conductor. I soldered the exposed half-inch of the cable to the INSIDE > of one end of the loop tubing. (You'll need a old-fashioned 150 > soldering iron or a Berz-O-Matic torch to heat up the copper tubing > (not a wimpy electronics pencil or temp-controlled soldering station) > since the copper is such a good conductor of heat! I then jammed the > remaining 36 1/2" of dielectric-covered center conductor into the open > other end of the copper tubing. Push it in until the loop is nearly > closed with only a 1/4" so so gap between the two ends. > > > This construction creates a coaxial capacitor with the coax cable center > conductor being one plate and the INSIDE of the copper tubing being the > other plate. The 36" or so of cable inside the tubing creates a > capacitance of about 75pF required to resonate the loop. Normal 50-ohm > coax has a capacitance of about 30-33 pF/foot. The snug fit between > the center conductor/dielectric, and the inside diameter of the tubing, > very closely duplicates the geometry, and thus capacitance of the > original coax . (You could literally make your own copper hardline > from this tubing by pushing yards and yards of center > conductor/dielectric from RG/8, RG/213 or RG/214 into it.) > > > You tune the loop to exact resonance by pulling the loop apart, or > pushing the loop together exposing more or less of the coax cable. > (Only the portion of the coax opposite the tubing's inside diameter > contributes to the capacitor value.) In my model, I had to expose about > 3/8" of the dielectric to get to 10.149 MHz. The tuning is VERY sharp > (indicating hi Q and high efficiency). A change of 1/8th inch moves the > resonance about 100Kz. The bandwidth for 2:1 SWR is only about 12 > KHz. This is actually an advantage for single frequency operation - > the antenna is so selective that transmitting on other HF bands > simultaneously won't desensitize the 30M receiver at all. > > > Finally, create the coupling loop. I cut 22" of normal #14 THHN copper > house wire, formed it into a loop approximately 7-1/2" diameter and > soldered the ends to the center conductor and braid of any convenient > length of 50-ohm coax to reach to the radio. This loop is then placed > so that it is about 1/4" away from the inside circumference of the large > loop on the side opposite the open-ends/capacitor. I drilled a couple > of additional holes in the PVC pipe to support the small loop in the > proper orientation. By bending (distorting this circle) so that more or > less of it is closely parallel to the big loop, you fine-tune the SWR at > resonance. Mine has an SWR of under 1.5:1 at resonance. > > ------------------------------------------------------------------------ > > > > > ------------------------------ > > _______________________________________________ > aprssig mailing list > aprssig at tapr.org > https://www.tapr.org/cgi-bin/mailman/listinfo/aprssig > > > End of aprssig Digest, Vol 69, Issue 9 > ************************************** _________________________________________________________________ Hotmail: Powerful Free email with security by Microsoft. https://signup.live.com/signup.aspx?id=60969 -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://www.tapr.org/pipermail/aprssig/attachments/20100309/a3e4a929/attachment.htm>
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