My Week in Radio
- Took down my 2M antennas to straighten and resolder.
- Catching up the radio blog with my recent experiences.
- Trying F4HWN firmware on Quansheng radios
- previous firmware, AUBSUK, for my Quansheng radio was skipping channels when I activated more than 1 scan list.
- larger display with single VFO
- rethinking my scan lists
- the S-meter is calibrated differently from the other firmware
- no questions, because I should just be reading the antenna book
- FT Challenge coming up in 2 weekends. *** Others
- KD3ACF, JT:
- acquired a j-pole for the attic
- new ham with an HT
- magmount on the car, tested with WA3VEE from Manheim High School
- W8CRW, CR:
- 985 activities
- Red Rose activities
- Salem CCARS acitvity
- W3QP, Tim:
- trip to HRO
- planning trips
- WA3VEE, Ron:
- working on an old receiver
- re-capping
- Hammerland hq140x
- terrible, loud 120hz buzz, so ordered capacitors to replace them
- cleaned
- fixed
- needs just a little more work, alignment
- got over to KC3YSM, Steve’s place to help with his antenna
- analyzed
- Buckmaster OCF dipole
- working on an old receiver
- KC3RFG, Jim:
- watching 10m
- Croatia, Belgium
- repairing the 160m/75m dipole, new balun
- AF3Z, Jim:
- testing his 1-tube QRP transmitter
- practiced some CW with a friend on 10m
- found sweden and belgium lower in the band.
- KC3OOK, Bill:
- 985 net, simplex net
- working on tower
- helping Joe, W3GMS, assemble his new tower
- KC3SCY, Luke:
- lots of time off from school this week
- 10m has been wide-open
- spent some time on 40m SSB and AM
- KC3VRW, Phil:
- attempted to build a 10m inverted-V
- MFJ tuner
- trying tech HF frequencies
Questions
- W3QP, Tim: Follow up on battery measurements for the TSA,
Watt-hours instead of Amp-hours.
- bigger batteries have bigger thermal events.
- Wh is the amount of potential power.
- Wh doesn’t require doing the math to consider voltage in combo with Ah.
- 18Ah at 12V.
- The nominal voltage for the cells is less.
- Expected usable volts are even less, so Wh is less than just V*A.
- Nominal voltage can be different across different battery chemistries.
- Nominal voltage may not be obvious.
- 11.1 Nominal voltage might be 12.6V at peak charge.
- Volts and Amps are important for application, but Watt-hours is better overall for capacity.
- AF3Z, Jim:
- tinkering with Hartley oscillator:
mica capacitors, ceramic capacitors,
what’s the difference of all the different capacitors?
- WA3KFT, John:
- ratings: capacitance, voltage.
- The “dry electrolytic” is a paste, not oil.
- main purpose is filtering AC converted to DC.
- filtering some frequencies
- ceramic capacitors are pretty stable, until overheated.
- mica capacitors are small capacitances, pF. used for frequency stablizing.
- variable air capacitor
- oil filled are higher capacitance and used for low frequencies in power supplies, etc.
- WA3VEE, Ron:
- film capacitors
- different dielectric
- used for audio.
- paper capacitor
- dielectric is anything that separates the plates.
- air capacitors
- film capacitors
- W3QP, Tim:
- silver mica are maybe lower loss than ceramic
- multi-layer capacitors for higher currents
- W3DIB, Greg:
- negatives of certain capacitors:
- some dielectrics leak
- tantalums can dead-short, like in a power supply.
- saw a cool video of people building filters for cheap radios in places with heavy RF to keep them working better.
- negatives of certain capacitors:
- WA3VEE, Ron:
- they leak when they get overheated.
- leads to the plate have a little resistance so generate heat.
- capacitor can have a vent that leaks under pressure.
- NA3CW, Chuck:
- capacitors are deceptively complex
- all components have some bit of capacitance, inductance, resistance.
- vacuum dialectric for especially high voltage.
- lots of trade-off characteristics
- some are piezoelectric (microphone), like a condenser microphone
- WA3KFT, John:
- tinkering with Hartley oscillator:
mica capacitors, ceramic capacitors,
what’s the difference of all the different capacitors?
- WA3VEE, Ron:
- homework: does a capacitor allow current to flow through it? KC3SQI, Wayne:
- solar telescope demos on December 11 at some park