My Week in Radio

• discovering some good old packet radio
  • 145.010
  • listen with multimon-ng
  • search for a terminal program for android and linux
• patched my favorite firmware (f4hwn) to better render the spectrum analyzer for wide or narrow scan ranges
  • built and tested on my own radio
  • patch was accepted to the open source project, so it’ll be in the next release
• POTA in the cold in prep for field day

Others

• W8CRW, CR:
  • new radio from HRO
• WA3VEE, Ron:
  • after 985 breakfast, at field day site, will be introducing radios for field day
• KC3RFG, Jim:
  • first Raspberry PI kit for a Ham Clock
• KC3YSM, Steve:
  • nets and POTA
    • all US: GA, AL, MI
• AB3AP, Mike:
  • hanging out on 30m
  • learning to touch-type instead of handwriting from CW
    • ARRL MP3s online
    • 15 WPM typing, 18 WPM is a challenge
    • jots keywords usually to be faster
• KC3OOK, Bill:
  • hosted last roundtable
  • net control for simplex net
  • working on ham shack
  • windy: gust of 39mph, antenna survived
• KC3SQI, Wayne:
  • couldn’t get to the repeater due to lots of QRN from powerlines, trains, etc.
• AF3Z, Jim:
  • SKCC had a weekend sprint-a-thon.
    • operated from Cornwall station as W3CRS
    • they were in 1st place until other clubs started uploading logs :)
• W3MFB, Mike:
  • experimenting using gutter and down spout and speaker wire as HF antenna
    • 10W and it worked.
    • recommending a similar setup to a friend

Questions

• WA3VEE, Ron:
  • We’re putting together some seminars/classes to share experience and knowledge.
  • What would you like to talk about? theory or operation?
  • NA3CW, Chuck:
    • get the scope and meters out and discuss impedance, etc.
  • KC3OOK, Bill:
    • Ron’s discussion on oscilloscopes
  • AF3Z, Jim:
    • general approach to trying to fix something
    • how to check equipment: bandpass filters, crystals
  • W3MFB, Mike:
    • understanding solar data
  • NA3CW, Chuck:
    • propagation
  • KB3ZIM, Bob:
    • revisit antennas and feedlines and their attributes
  • KC3WWC, John:
    • kit night to build something
    • favorite equipment on the bench that others should have
  • KC3OOK, Bill:
    • soldering technique
    • all basic test equipment
    • NA3CW, Chuck: validating readings from equipment
  • AF3Z, Jim:
    • surface mount soldering
    • NA3CW, Chuck: good tweasers
  • KC3RFG, Jim:
    • refresher on setup and use of NanoVNA
  • W3MFB, Mike:
    • soldering coax
  • KC3WWC, John:
    • digital modes old and new
  • AF3Z, Jim:
    • sorting out limitations of test equipment, signal levels
  • W3MFB, Mike:
    • tutorial for the young folks, how to build a repeater
  • KC3SQI, Wayne:
    • how do you find an interfering signal, fox hunting.
  • KC3OOK, Bill:
    • basic circuits
  • NA3CW, Chuck:
    • understanding antenna gain

I discovering some ax.25 packet radio floating around on 145.010MHz. I connected my Btech APRS audio cable from computer headphone/mic to the Quansheng, and piped the audio into multimon:

$ pw-record --channels 1 --rate 22050 - | multimon-ng -t raw -a afsk1200 /dev/stdin

Here’s some of the traffic I decode:

  AFSK1200: fm AA3RG-7 to ID-0 UI^ pid=F0
  TheNet X-1J4  (PINEGV)
  AFSK1200: fm AA3RG-7 to N3FUD-7 RR4-
  AFSK1200: fm AA3RG-7 to N3FUD-7 RR4-
  AFSK1200: fm W3AVP-5 to ID-0 via AA3RG-7 UI^ pid=F0
  W3AVP Packet System - FN10xc
  W3AVP-5: New Holland Chat
  W3AVP-10: Winlink Gateway
  AFSK1200: fm AA3RG-7 to N3FUD-7 RR4-
  AFSK1200: fm W3HZU-0 to N3FUD-7 RR4-
  AFSK1200: fm W3HZU-0 to ID-0 UI^ pid=F0
  YORKPA:W3HZU  Connect W3HZU-1 BBS & W3HZU-11 CHAT
  AFSK1200: fm AA3RG-7 to N3OGS-7 DISC+
  AFSK1200: fm AA3RG-7 to N3OGS-7 UA-
  AFSK1200: fm AA3RG-7 to N3FUD-7 RR5-
  AFSK1200: fm W3HZU-0 to N3FUD-7 RR4-
  AFSK1200: fm N3DWB-0 to QRZ-0 via KA3TKW-0,PINEGV-0 UI^ pid=F0
  N3DWB JONESTOWN FN10SJ
  N3DWB-1 Mailbox
  AFSK1200: fm N3DWB-1 to MBX-0 via KA3TKW-0,PINEGV-0 UI^ pid=F0
  Mail for: None
  AFSK1200: fm AA3RG-7 to N3FUD-7 RR5-
  AFSK1200: fm W3HZU-0 to N3FUD-7 RR4-
  AFSK1200: fm AA3RG-7 to N3UOO-7 UA-
  AFSK1200: fm W3HZU-1 to WA3USG-1 via KA3TKW-0 SABM+
  AFSK1200: fm W3HZU-1 to WA3USG-1 via KA3TKW-0 SABM+
  AFSK1200: fm WA3USG-1 to W3HZU-1 via KA3TKW-0 UA-
  AFSK1200: fm WA3USG-1 to W3HZU-1 via KA3TKW-0 I00^ pid=F0
  [KPC3P-8.3-HM$]
  95529 BYTES AVAILABLE
  THERE IS 1 MESSAGE NUMBERED 13
  ENTER COMMAND:  B,J,K,L,R,S, or Help >
  AFSK1200: fm AA3RG-7 to N3FUD-7 RR5-
  AFSK1200: fm W3HZU-1 to WA3USG-1 via KA3TKW-0 I10+ pid=F0
  [BPQ-6.0.24.33-IHJM$]
  AFSK1200: fm W3HZU-1 to WA3USG-1 via KA3TKW-0 I10+ pid=F0
  [BPQ-6.0.24.33-IHJM$]

I need to find a terminal program for Android (BPQ Term?), and read more about the anatomy of an ax25 packet.

There was a bug for a while in F4HWN 3.9 on the Quansheng radios. The spectrum analyzer graph was too narrow when number of bars exceded 128. I’d easily run into the problem when I set the scan range to 144.000MHz to 148.000MHz, and activate the spectrum analyzer.

I dug into the code a bit and fixed it, so now it scales for large and small ranges.

I submitted a pull request to the project, and it was accepted and merged to be included in the F4HWN 4.0 release. Until that release, I’ll be running my custom build.

I also made a change to allow me to map the spectrum analyzer to a programmable side button like AubsUK had, but I’m no longer convinced it’s worth the limited code space it would consume in the binary.

My Week in Radio

• ARRL RTTY RoundUp
• Testing and repairing a piece of coax
  • no damage in the middle
  • NanoVNA, Smith chart, compared ends
    • one side showed a long spiral
    • other end showed no change upon being connected
    • so I knew I found something
  • compared to a working cable
  • cut off the end and replaced the SMA connector and it worked

Questions

• KC3OOK, Bill:
  • For lifepo4 batteries, what’s the proper way to charge and discharge?
  • W3QP, Tim:
    • depends how often you use the battery.
    • for storage, 50% capacity is good
    • otherwise charge it up full.
    • don’t keep it full all of the time.
    • not much of an issue, though
  • W3MOW, MIKE:
    • researching electric vehicles.
    • whatever you do to treat it better will just prolong battery life a bit
    • there will be better replacements in a couple years.
• KC3WWC, John:
  • I’m using my 71-foot random wire with a 9:1 unun.
    • I can give it 5W on many bands without the tuner.
    • It’s working, so not all loss.
    • Checked it at with the NanoVNA at different points and it stayed pretty low.
    • Disconnecting the wire definitely ruined SWR, proving to me that power is getting out into the wire, besides it otherwise working.
    • What am i seeing?
  • W3QP, Tim:
    • SWR is great for a rough indicator for reflected energy
    • reactance is more important for efficiency
    • losses can mislead you with SWR
    • any piece of wire will resonate at different harmonnics
    • had a shorter wire was resonant at some harmonics that happened to work
  • KC3SQI, Wayne:
    • with a random wire, the balun takes SWR of the antenna and reduces it by a factor of 10.
    • Tuner can offer extra protection for the radio
    • a random wire antenna is to be a bit off and close enough for most radios
    • he uses his random wire 71-foot random wire he uses for POTA, but barely needs the tuner.
  • NA3CW, Chuck:
    • every SWR meter is measuring voltage, current, and time.
    • ratio of voltage and current = resistance
    • a resonant antenna can have a high SWR because it’s feed impedence is not matched.
    • measuring voltage, current, reactance.
    • meters can be calibrated for other impedences, not just 50ohm.
    • SWR compares voltage, current, phase (time) with internal 50ohm reference.
    • watch amplitude of voltage and current on scope, and see it out of phase.
    • can have a low SWR on non-resonant antenna
    • can have high SWR on resonant antenna
    • longer pieces of wire can have more resonances
    • resonances may or may not fall in useful places.
    • low SWR does not mean efficient. could be losses.
    • all lengths of wire will have certain resonances.
    • everyone went with 50ohms as a standard.
    • TV coax is 75 ohms.
    • transformers get it close to what the radio wants.
• KV3JGB, Matt:
  • He has a Vibroplex, single lever, usually thumb is dit, finger is dah, but he’s reversed the dits and dahs for comfort.
  • Does it matter if he works reversed?
  • AF3Z, Jim:
    • probably doesn’t matter
    • he learned left handed first then right
  • WA3KFT, John:
    • read about telegraph keys and bugs (semi-automatic keys)
    • Vibroplex made a mechanical key that’s left-handed
  • AB3AP, Mike:
    • left-handed bugs are more expensive
  • KC3WWC, John:
    • I key left-handed, and I’ll have to reconfigure anyone else’s radio, or flip the key.
    • I just flipped the key to reverse it, and was able to adjust with a moment of practice.
• KD3AIS, Tim:
  • Who would you suggest to help install an antenna on the chimney?
  • KV3JGB, Matt:
    • lots of people are willing to help
    • antenna launch parties
    • Matt would help
  • KC3WWC, John:
    • try compromised installations for some more independent capabilities
  • NA3CW, Chuck:
    • come to a breakfast
    • let’s talk about your intentions, site, etc.

My Week in Radio

• My favorite way to learn things: experiments
  • diagnose and repair a bad coax cable
    • no continuity on center conductor
    • plugged it into the nano vna, switched to smith chart
      • saw a big spiral around the outside
      • no change in the graph on the other side
      • compared to a working cable
      • it should have spiraled
      • maybe alonger spiral for a longer cable
  • 71 foot random wire with 5W is not needing the tuner
    • disconnected lots of different places and checked lots of SWR without those connections
• Tossed a wire into a tree at Swatara State Park today for some POTA contacts
• Operated the last 2 hours of the RTTY contest on 10m, 15m, and 20m.

I made my first trip to US-1426, Swatara State Park for a quick activation. I stretched the 41-foot EFRW to a tree right from the car window, and made 13 FT8 contacts on 40m.

I had a bit of bad coax on the most recent POTA, so I set out to test and repair it. I saw no damage to the cable or connectors, but there wasn’t continuity across the middle wire.

Which end is likely bad? I connected each end to the nanovna with a Smith Chart. I found on one end, the smith chart traced a spiral around the outside of the circle. The other side did not react at all, like I hadn’t connected anything. For comparison, I tried another cable I figured was good. That other cable had continuity to each end, and both ends each traced a spiral on the smith chart. The length of the spiral seemed to be related directly to the length of the coax: shorter traced shorter and longer traced longer.

So with that, I replaced the one end that didn’t react, and now the cable looks good.

I was using the 71-foot (21.64m) EFRW antenna at home, and I noticed SWR was surprisingly low as measured by the X6100 with the tuner disabled. I suspected loss on the feed line, but I also found this video of another person not using a tuner with the same antenna.

I disconnected my feed line at different places to find SWR jumps way high, so the measurement is working:

• inside window
• outside window
• at the antenna

Does a very long wire have low SWR for everything? Is the 9:1 giving low SWR? The antenna’s working fine, and FT8 shows far-flung signals like always. Disconnecting antenna wire raised SWR above 1.5:1, but not much. Even with wires disconnected from the balun, it’s receiving a very few FT8 signals on 10m, and I can still transmit, but it’s folding back power with SWR just below 2. The tuner is definitely needed for 6m.

My Week in Radio

• ISS on scan, so I caught part of an image
  • passes are a bit early right now, and low
• Nice weather
  • local POTA including a couple solid CW
  • some maintenance of the VHF antennas
• Noticed today I can disable the tuner on my random wire antenna and still get OK SWR
  • sounds like loss to me
  • but putting 5W into the wire is still getting identifiable weak signals to Europe, Alaska, etc.
• Reading the AllStar manuals
• Adding 4:1 balun to my list of things to build
  • delta loop
  • Rybakov vertical

Others

• KC3SCY, Luke:
  • crystal receiver
• W8CRW, CR:
  • working on a 10m antenna
• W1RC, Mike:
  • likes SWR tools, since antennas are the final frontier
• AF3Z, Jim:
  • took the Kenwood mobile out of the car to replace the memory battery
  • how’s my audio?
• NA3CW, Chuck:
  • Jim is low
  • arcing in a band switch, so disconnected 10m taps to avoid problems
    • added some feed line and changed antennas, so maybe time to try fixing it to do 10 again.
    • works now
  • finding some bad solder joints in some coax.
  • been in repair mode
• KC3OOK, Bill:
  • working on Joe’s tower again soon
• WA3VEE, Ron:
  • presenting in Pottstown on Friday on antenna analyzers
  • May be visiting the field day site
• KC3YIG, Dave:
  • picked up Alaska
• W3QP, Tim:
  • 2 SOTAs in Western PA
  • new Retevis 25W radio
• KV3JGB, Matt:
  • fixing some lines to get an antenna up in some trees
    • it’s working
    • first contact on 10M
    • also 15M for a rag chew
  • starting CWOps on Friday
• KB3ZIM, Bob:
  • published in latest QST, page 20
• KC3NZT,
  • testing coax with NanoVNA

Questions

• KC3SWC, Charles:
  • How do 12V batteries apply to Winter Field Day? li-ion, lead acid, deep cycle lead acid, AGM, gold cart batteries, lifepo4. What are the advantages and disadvantages of each.
    • WA3VEE, Ron:
      • at field day, we won’t be charging any batteries inside
      • uses AGM and lifepo4 for radios, no trouble in cold weather
      • AGM vents, so ensure it has ventilation
    • W3QP, Tim:
      • lifepo4 is a good choice for amateur radio
        • lighter
        • output amperage is usually only 2x capacity
    • W3MFB, Mike:
      • used marine cells lots
• W3FES, Fred:
  • Troubleshooting a switching power supply.
  • Rated for 15 amps.
  • Running a radio, 15W output
  • Voltage drops to 8V.
  • What can he do to diagnose the problem in the power supply?
  • WA3VEE, Ron:
    • need to look at the manual to see ratings
  • NA3CW, Chuck:
    • switching power supplies are usually working or dead

My Week in Radio

• ISS on scan, so caught part of an image
  • passes are a bit early right now, and low
• POTA yesterday:
  • 2 CW + 28 FT4 contacts on 20m
  • pretty rusty on throwing the line into the trees
  • bad section of coax
• some antenna maintenance on a nice day

Others

• K3EA, Greg:
  • Special event station with local station:
    • W2T, Battle of Trenton
    • W2P, Battle of Princeton
  • Contests
    • Canadian Winter Contest
    • next weekend
      • ARRL kids
      • ARRL RTTY Round Up
    • NA QSO party
    • https://contestcalendar.com/
  • Propagation report and DX
    • Dominica
    • Fiji: 3D2GE, CW only
    • watch the DX clusters
  • after DXCC award, go for every country on every band.
• WB3LNY, George
  • built a new pc with chirp, and synced up all his HTs
• VE3HOH, Pete
  • cleanup, indoors.
• KA3TKW, Tom:
  • ISS on night shift: good passes aren’t during the day.
    • there’s a packet digipeater
    • SSTV is active
    • it was only doing telemetry over the weekend
  • good passes for SO-50
  • https://n2yo.com/
  • ham lunch had about 32 people
  • thanks Glen for talking about DXCC
  • zbitx
    • 5 watt QRP SDR TRX
    • will be buying one
    • shipping in February
    • 44 bit ADC
• K3DMM, Denny
  • caught SO-51 with a Baofeng 701
• KC3VZU, Bob:
  • setup a new TYT 9000D with a slim jim outside
• KK4KKW, Steve:
  • new end fed antenna strung into the trees, inverted L, trying it on 10M
• KC3ZBI, Ron:
  • new antenna that’s not on the car now,

Swap and Shop

• WB3LNY, George
  • dummy loads
• VE3HOH, Pete
  • paddles, bugs
    • vibroplex
    • brown brothers
  • oscilliscopes
  • a couple Drake TR7s
  • tower sections
  • a couple Kenwood 130s
  • email is good on http://qrz.com/
• KA3TKW, Tom:
  • 2 shortwave receivers: RadioShack DX440
    • 0-30MHz all mode
  • UHF motorola repeaters, 25W
  • Yaesu FT1XD, dual band, APRS
• K3MIJ, Troy
  • looking for a commercial propane generator