24V rig, ham radio transmit causing stereo issues

[mulebarn]

Hey folks,

I’ve read something about this before, but can’t find it for the life of me. My HZJ73 is 24V, and I’m running a 24v to 12v stepdown coverter for the Alpine stereo and Yaesu ham unit. The stereo allows me to use Apple CarPlay. Whenever I transmit on the ham radio, it shuts down the connection of my phone to the stereo. What’s causing this? Is there a fix?

Thanks.

 

[fireball]

What wattage is the step down converter and how many watts is the ham pulling when it transmits?

you are likely overloading the step down converter.

 

[mulebarn]

I’m a ham newbie. My transmitter looks to have 3 wattage output options. How do I know which I’m using? I think it’s transmitting 50 though, to answer your question.

 

[lugueto]

What radio are you using?

 

[mulebarn]

Yaesu FTM-400DR

 

[fireball]

What converter are you using? What are the specs?

It looks like your ham consumes 12amp during 50w transmission.

 

[bj70_guy]

If you're transmitting at 50W your radio is probably drawing between 6 and 10 amps. How big is your 24-12V converter?
Try setting the radio power to low and see if the stereo still cuts out when you transmit at 5W.

 

[mulebarn]

Thanks y’all. I’ll give it a try, and report back. Might need a beefier converter.

 

[lugueto]

The reason I asked what radio you were running was to see how much power you were drawing to point out that you probably need a larger converter or use independent converters for your stereo and your radio.

You'd be surprised how much power a HAM radio needs to work properly.

 

[mulebarn]

They’re on independent converters, so it’s looking like a RF overload. I’ll test soon.

 

[mulebarn]

It turned out to be a transmission power issue. My radio has three power settings, and as long as I’m not transmitting at 50w this doesn’t happen. Thanks for the ideas y’all.

 

[fireball]

Glad you found a workaround however I’d still be curious to know the size of your step down converter and if that is the issue.

Dialing back the tx power of the ham seems like a compromise.

 

[mulebarn]

The ham radio is on its own converter, so unlikely, especially because it isn’t shutting the stereo off; it’s just causing enough RF interference to interrupt Apple CarPlay. I’ve asked others on a couple of HAM groups, and it’s apparently a thing. They say you can achieve the same effect (even turning a stereo off) by getting close to a commercial radio or tv tower. My good buddy can turn on his neighbor’s tv with his ICOM HF radio (Haha).