My Week in Radio
- POTA over the weekend
- in addition to digital, practiced some CW
- enjoying new Gabil whip with sliding coil
- got some other CW contacts from the camp site
Others
- N3CGA, Keith:
- studying for extra
- hiking around Pine Grove Furnace and Appalachian Trail
- operating VHF repeaters
- WA3VEE, Ron:
- installing radios in the new van
- Mullica Hill Hamfest coming up
- NA3CW, Chuck:
- usual 985 nets and PMAM net/pre-net
- working at Joe’s on tower project
- KC3OOK, Bill:
- working up the tower at Joe’s, aligning mechanical things
- south control for Simplex Net
- KC3SQI, Wayne
- working on his own tower
- home-run coax cables are buried
- moving 2M off the garage to get it to the tower.
- KD3APR, Paxton:
- just broke 2 HTs by dropping
- diagnosing some ribbon cables
- learning about DMR
- battery life is surprisingly good on these cheap HTs
Questions
- KC3SQI, Wayne:
- Looking for an effective disconnect for some accessible powered fishing reels. He has anyone used barrel connectors for this application. It’s just a 3A motor. The 5525 plug is not waterproof.
- NA3CW, Chuck:
- should handle 3A, depending if it’s tight enough.
- KC3NZT, Harvey:
- assuming wire’s good gauge, it should be fine.
- mismatches in the pin size could be a problem
- they sometimes get weak.
- GM-style blade connectors are common, waterproof, and cheap.
- in marine, bullet connectors can be fine, but not waterproof. can be quick-release for safety.
- KC3SQI, Wayne:
- still early prototype, so this is good info.
- AF3Z, Jim:
- He has an Astron linear VS-50M with an LM723 chip in it (regulator?), and an SCR and capacitors across output. When it’s been off for a while, upon powering on, the voltmeter needle will stay low then pop up. He uses an extra breaker/switch to turn on the radio after the voltage has stabilized. Initial load on the supply causes it to take very long to come up to ready. What’s its problem? https://www.ameradio.com/product/420223/description.html
- WA3VEE, Ron:
- sounds like a capacitor issue.
- SCR can be there for over-voltage.
- maybe a resistive connection on the capacitor itself?
- make sure caps are connected well.
- NA3CW, Chuck:
- is it a soft-start mode that limits current?
- seems like a problem, though.
- AF3Z, Jim:
- built-in ammeter barely registers anything
- W3GMS, Joe:
- separate supplies for 723 and the path transistors, since they want different voltages.
- secondary winding on transformer vs “tertiary” windings.
- it’s not a slow-start control.
- SCR has current limit pins looking for 0.7V differential.
- if you don’t see the right voltage, it’ll rob base current and cause output to go to 0V.
- best to check it with a scope and float the ground during the test.
- analog meter might be ok, but digital might have too latency.
- look at CL and CS for voltage.
- KC3NZT, Harvey:
- He has a receiver that shows a fault that the antenna is shorted to ground. It’s a bad module, but as a receiver, do receivers generally use discrete components, say in the matching network, that could fail?
- KC3SQI, Wayne:
- some will have a diode in the module to bleed off residual voltage from the antenna going through the wind
- could use RC network to do the same thing
- NA3CW, Chuck:
- is the input of the receiver a built-in antenna or external?
- it could have a bias voltage that it could monitor and know there’s a problem.
- if there’s a coupling capacitor that’s failed, it may know that.
- it could be monitoring and expecting a certain level of background noise
- KC3NZT, Harvey:
- it’s an external, passive antenna on 15ft of coax.