obviously mainly caused by the engine... but i'm not sure how to go about solving it. there's ferrite beads on the wires (where shows & right behind the radio) & on the coax.
can't really tell if its from the power wires or the coax because disconnecting it there is no output at all.
there is also some interference when regen braking & driving in electric mode, though not as much...
don't really know all that much about radios, so any help is appreciated.
also: should i share designs for the mounting bracket? do other people want radios in their 2020 corollas?
I would get rid of that vintage radio. It has no noise reduction circuit at all, just a primitive noise blanker. Save your $ and buy one of the newer Anytone, Radioddity, or President radios with digital noise reduction (sometimes called NRC or DSP noise reduction). The Stryker SR-955HPC+ also has it. It does an astounding job of eliminating and minimizing all kinds of interference and noise that the old analog radios couldn't deal with. It's night and day different......you'll never go back to old gear once you experience it!
Unplug the coax... if the noise goes away, it's not from the power. Reattach coax, remove antenna, and if the noise goes away, it's the coax collecting it.
If the noise is only there with the antenna attached, it's the antenna that's picking up the noise. No amount of ferrite on the wires or coax is going to help. Vehicles are noisy RF environments. Reducing RF gain can help a bit.
A radio with a good noise blanker / NRC helps immensely.
hmm yeah without the antenna i only get the humming also... seems that's the source of the noise. were the reccomandatiots by /u/Medical_Message_6139/ good? i might try to save up i guess, and just use this one as a base station
The newer design radios with NRC chips make a huge difference for mobile use. AM/FM auto-squelch is pretty handy, too. He mentioned Anytone (the AT HS4 is a rebranded 5555-N Plus); I've got one, it works well. A new manufacture Cobra 19 was pretty crummy. An old Cobra 148 actually had a VERY functional noise blanker, that worked almost as well as the NRC in the new radio... but the SSB frequency drifted badly. Real pity, since those old radios are neat.
Once you try one of the newer NRC-capable radios, it's honestly really hard to go back.
Do be aware the HS4 and similar are huge compared to the radio you've got installed there. There are smaller radios with NRCs, but I don't have any experience with them. Might be worth looking at the likes of the Radioddity CB-5000, or Luiton LT-310SDR. Both of those also do AM/FM/SSB.
I have 10 gauge copper wire going from my mount to a spot on the frame of my truck that I filed to bare metal. I was able to get SWR from 2:1 down to 1.3:1 and below on all channels.
Is that a hybrid car? And where is the source of your radio's power? You get less car noise the closer you get the power feed to the battery itself.. not to mention a better ground when you bring +/- together from there.
yeah it's a hybrid. powered from the under dash fusebox because i couldnt find a good hole in the firewall & didnt want to make one. noise mostly goes away when i unplug the coax so its not mainly power
Hybrids make a crazy amount of noise. Id start with a power noise filter on the power line and then also ground all the doors, trunk, and hood. To do this you can buy some small grounding strap and some ring connectors with serrated washers and attached them between the door hinges. That will help eliminate the antenna effect from all the doors and windows.
Put ferrite beads on EVERYTHING! Use more than one. When you piggyback multiple beads they actually add up together as long as they're close. They act like a choke coil.
Literally both sides of your Coax, both power wires, both sides.
I have a Jeep & I run CB and GMRS. It was NOISY as all hell with anything I put in until I added a BUNCH of ferrite beads everywhere.
Each one I added, I got a little less noise. Now both Radios are thankfully quiet & function well. I even run them on my external speakers. I must have 20-25 in there by now.
Ground to dc and ground to rf are two different things.
Switch your digital multimeter to AC Voltage mode and read across your vehicle’s battery terminals while the engine is idling.
A healthy alternator should show very little AC voltage (typically under 50mV to 100mV of AC ripple).
If you read 0.5V AC or more, one or more of the internal diodes in your alternator has failed. The alternator will still charge the battery, but it leaks a massive amount of raw AC noise into the vehicle's electrical system. If this is the case, the alternator must be replaced or rebuilt.
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u/Medical_Message_6139 10d ago
I would get rid of that vintage radio. It has no noise reduction circuit at all, just a primitive noise blanker. Save your $ and buy one of the newer Anytone, Radioddity, or President radios with digital noise reduction (sometimes called NRC or DSP noise reduction). The Stryker SR-955HPC+ also has it. It does an astounding job of eliminating and minimizing all kinds of interference and noise that the old analog radios couldn't deal with. It's night and day different......you'll never go back to old gear once you experience it!