Sparc

• https://www.geochron.com/
• Owner: Patrick Bolan
  • rides motorcycle around and visits geochron users
• mechanical clock since 1964
  • automated map to show greyline
  • backlit
  • 6ft map that turns on gears
  • shades moved by motors
  • seen in movies: twister, clear and present danger, hunt for red october,
  • Ronald Reagan had them
    • gave Gorbechev one as a gift: American ingenuity
  • Geochron still has a mechanical shop to service them
    • refurbish 300 / yr
    • build 100 / yr new
    • $2500-$4000 for new mechanical
    • 25 hours to assemble
• Geochron Digital
  • renders 4K on the client
  • pulls maps and data from geochron
  • HDMI
  • used on carnival cruises, since light on internet
• his geochron shows:
  • pota
  • airplanes
  • weather / hurricane
  • naval carriers for US and others
  • aurora predictions
  • earthquakes
  • lighting strikes
  • noaa satellite images
  • fire hotspots in CA
  • pollution
  • remote controlled or by phone app
• ISS has a video feed you can show on Geochron, and you can see lightning
• Atlas 1 can’t render the newer animated overlays
• Atlas 2 and pro (new this week) show everything
• ham radio features
  • CQ zone maps
  • geocentric map
  • FT8
  • MUF
    • watch for “holes” on the way to a target where the signal would “escape”
  • filter by callsign prefixes (VK)
  • POTA / SOTA
  • ISS
  • satellites filtered by mode with footprint
  • QRZ logbook integration
  • where the moon is shining - moon terminator
• need to customize, since there’s so much data
  • opacity
• Atlas 2 - $425 -
  • 16 layers included with internet access
  • $2-11/month or more layers
  • email coupon@geochron.com for code
    • $425
    • free ham radio annual pass

General Meeting News

• Harrisburg Packet Node
  • W3ND
  • 145.010
  • 145.030
  • BBS available
  • vara-fm and winlink available soon
• K3IR active for PA QSO party at site
• picnic coming up in a month
• Red Rose Hamfest is Oct 4
• September meeting may be search and resucue
• at the training center October-March

Presentation: Winlink w/ Harry N3FMO

• winlink net
• saturn net: emergency services and salvation army
• initially, saturn was only during the day for retired people
• first weekend Harry ran the net on winlink, 20M, he got 70 check-ins.
• winlink is good for emcomm
• winlink is familiar as email
• lots of templates to use
• can use telnet if internet is available
• HF can be slow for a large volumes
• using telnet can keep RF available
• https://winlink.org/
• for Harry’s net, email: satemail
  • Noon Thursday - Noon Saturday
  • stations can be placed on the map with “mymaps”
  • name, city, state, country
• K3IR-10 connects to winlink RMS

At the SPARC meeting, we heard about Lancaster ARES with W3COB, Doug Rice.

• public service events
  • fun runs
  • motorcycle rides
• work with Lancaster ACS
• Eastern PA section -> section 4 -> Lancaster County
• exercises
  • April Towers
  • Peach Bottom Nuclear Plant
  • Skywarn
  • Firecracker 5-mile Run
• https://lancasterares.net/
• ARRL task book
  • sets standards for training and qualification
• 3 levels, including “basic”
• available trainings
  • arrl.org
  • FEMA
• stay active
  • train
  • participate
    • biweekly nets
    • monthly meetings
    • public service events
  • prepare
• Auxiliary Communication Service (ACS)
  • larger than ARES
  • https://serv.pa.gov/

We discussed meshtastic as always. I’ve been seeing more nodes, especially in York.

I re-soldered and terminated my small 1:1 chokes, since the ends had ripped off on last activation.

I had created a channel on my Meshtastic node for SPARC and at the Elmer night, we signed people up to use it.

Name: SPARC
PSK: WVaaYi2B/GJWGJwgbyXH7+na142aLwend1+UA2W2CPo=

W3IHM, Sam, presented the 900MHz band at the SPARC member meeting.

History

• 1926 - first regulation of amateur radio
  • before 1926, ban on anything belowe 200m
    • amateurs could do anything they want above 1.5MHz
• First regulations defined bands
  • harmonically related
• Amateurs imposed legislation for technical reasons
• 900MHz has been available to hams since 1926
• People wanted broadcast interference from ham radio gone in mid 1920s
• 1930s - allow anything above 110MHz
• 1935 - people were getting up to 3200MHz with magnetrons (spinning electron)
• Commercial broadcastsers pushed hams into bands and out of lower bands in 1920s when we started figuring out propagation in the ionosphere, and they wanted to broadcast around the world.
• war-1940 - we’re allowed above 300MHz
• 1941 - all ham radio is shutdown for war
• 1947 - military is reluctant to give back bands
  • bands shifted around a little
  • allowed up to 300GHz
• 1952 - added 15M
• 1979 - added WARC bands (12, 17, 30)
• 1986 - 33cm
• 2002 - 60M
• 2016 - 2200M, 630M
• Will we get 8M, 5M, and 4M like other parts of the world?

Characteristics

• 900MHz-928MHz
• Feed line loss is double that of 440MHz
• Antenna loss
• Atmospheric loss
• Simplex is pretty dismal
• Bounces well, like off airplanes
  • Once got Harrisburg to Philly bouncing off an airplane
  • Hit repeaters with Yagis and bounces
• It’s a shared band with some other services.

Possibilities

• Commercial radios with other software and surgery
• Harris radio - expensive software
• EF Johnson - free software, but needs surgery
• Alinco had something, but not available
• Kenwood TK981/481
• Retevis RT10 - 1W $80
• Listen with Quansheng, but filters won’t transmit.
• Baofeng with dirty harmonics might TX on 900MHz
• Baby monitors?
• SDR dongle
• Transverters

Shared Bands

• Power meters are everywhere in the middle of the band, and the noise causes the FM squelch to stay closed.
• Everyone’s trying to use the slivers on the end to avoid interference.
• Amplifiers can overcome the noisy power meters.
• Surplus amplifiers and antennas can be cheap.
• K3LV has a repeater in the area.
• Use it or lose it (already to the power meters).
• Power meters may go away after a while to move up to 2.4GHz
• Lots of competition for 900MHz - 2GHz - goes through the atmosphere easily.

I took along the old slim jim antenna I bought at my first ham fest. I understand now better how to tune it: I need to make it a little longer, not just slide the feed point up and down the batch.

The antenna was a little short by measurement with the NanoVNA. I hung it from a fan in the middle of the room to measure it without interference. I lengthened it at the far bend by soldering some extra house wire in the bend.

Now it looks perfect for 2m and 70cm.

There were only 3 of us at the SPARC elmer night, but we were on the same page. I compared notes on packet/APRS and WoAD with KC3QEH, JJ. We both had these new Btech-based radios. Even on the hill, our HTs with small antennas didn’t pick up much inside the building. I tried an external antenna from another club radio and I started receiving lots of packets. Sending APRS messages worked under the Signal menu: KC3QEH-7:TEST MSG

Club Business

• Elections
• Ideas
  • Looking for help with fox hunt
    • have the transmitters
    • can get help from other clubs

Presentation: DMR with Jason

• originally designed for professional radio installations.
  • lots of motorola gear
• developed in europe first
• digital voice
• data
• components
  • radios
  • repeaters
  • controllers (for routing traffic)
  • network infrastructure
• lots of networking and linking over large areas.
• types
  • tier 1 - consumer
  • tier 2 - professional, trunked
  • tier 3 - trunked, large-scale
• TDMA (time-division multiple access) - 2 channels / slots
• narrow bandwidth 12.5khz band
• modes
  • private
  • group
  • broadcast
  • data: text, gps, telemetry
• radio id is assigned by radioid.net to you and your call sign
• talkgroup = collecting a bunch of radio ids into a single contact
• popular public networks:
  • tgif
  • brandmeister
• can also be a private network
• hotspots access dmr network via the internet
• delmarvadmr.com
• 3 building blockse
  • talk groups
  • channels
  • zones

At the previous week’s meeting, many people built EFHW kits and untangled some wire to use with them. No one finished the build and brought them back, so I offered a quick demo of tuning such an antenna.

I connected my 49:1 unun that I’ve been using to a new wire we had hanging. We connected a handful of different analyzers to see how they operated.