#antennas — Public Fediverse posts

(reposting public, rather than quiet)

#HamRadio question: What types of #RF cable to buy and from where.

Low power < 1 watt
700 M to 5Ghz typical
DC to 6G sometimes.
Low loss is nice
50 Ω

Specific uses
1) making #antennas with matching or stubs.
Indoor and outdoor.
900 mhz #yagi
900 mhz folded #dipole

2) connecting antennas on patio to indoor radio.

( 900 mhz, UV / weather resistant outdoor, fire resistant indoor. Possibly flat cable at door. Lightning arr.)

3) connecting boards together indoors (filters, amps, SDR, etc)

What I think that requires:

5 feet of moderately stiff cable for making antennas, #LMR 240/400 or equiv?

10-20 feet of low-loss outdoor cable (not buried)

1-2 feet of thin / flat cable to pass around door.

10-20 feet low-loss indoor cable. Fire resistant?

10 feet thinner flexible indoor cable to interconnect boards.

Tools for cutting & crimping. SMA, RPSma, but ideally also other types (TNC, N, maybe BNC, maybe ufl)

Finally got the $10 ten-meter dipole out of the attic and into the air. I feel like a real ham now lol.

Interesting that I don't immediately notice a strong directionality difference in my FT8 contacts, though the antenna is nearly perpendicular to the attic direction and the 'inverted v angle' [what's that called?] of the radiators has been small in both instances.

#10meters #FT8 #dipole #antennas #HamRadio

Landsat At Work – Better Wireless Communication - National Land Cover Database (NLCD), Based On Landsat, Helps Plan Clear Signal
--
https://www.usgs.gov/centers/eros/news/landsat-work-a-path-better-wireless-communication <-- shared article
--
https://www.usgs.gov/landsat-missions <-- shared about Landsat
--
https://www.usgs.gov/centers/eros/science/annual-national-land-cover-database <-- shared about NLCD
--
#GIS #spatial #mapping #Landsat #remotesensing #satellite #earthobservation #fedscience #usecase #USGS #EROS #cellphone #mobilephone #telecommunications #communications #cost #benefit #wireless #towers #antennas #landcover #landuse #NLCD #radio #frequency #siting #lineofsight #clutter #economics #risk #hazard #signal #signalquality #USA #value #returnoninvestment
@USGS @USGS_EROS

I found this video today (it’s been on YouTube awhile) offering more technical info on the #ANFLR9 #ElephantCage #antenna than you’ll find anywhere without doing a lot of reading. The presentation includes this graphic, which is the first I’ve seen comparing the size of an #ElephantCageAntenna to the size of the U.S. Pentagon: https://youtu.be/4sgAGWPNSUQ

#ColdWarHistory #ColdWarTech #MilitaryIntelligence #FLR9 #Antennas #RAFChicksands #Elmendorf #SanVitoItaly #MisawaJapan #FieldStationAugsburg

Now I can just share the link and say, “this is what we were doing, and this is how and why.” Not only that - apparently this is what a new generation of young Morse Ops is continuing to do for the government - at least as of September of 2020. #UnitedStatesAirForce #DittyBoppers #MilitaryIntelligence #ColdWar #FLR9 #Wullenweber #Antennas ~ https://youtu.be/uh88Y2_33GI?si=jIP4C92PbaQUkaz4