Isolate radio with a relay?

[cruiser guy]

How do you all have your ham radio hooked up? Did you go direct to the battery with a relay to keep the radio isolated from voltage spikes at startup or not?

I'm leaning towards using a relay wired through the auxiliary switch position to protect the finals on my radio.

 

[DaveInDenver]

I voted for the relay, although I only isolated the positive lead on my radios. I ran the power straight from the battery to the relay and use the ACC setting so that the radio will be off with the key off and while starting. Probably not necessary, but I figured it couldn't hurt. Plus I tend to forget to turn things off and I'd hate to have a dead battery with no one around.

 

[gary in ohio]

Since most radio's are designed to be connected directly to the battery they can handle the loss of voltage at starting, if concerned one of those BIG stereo caps will ease out the voltage drop.

I do however have a rely in mine to allow me to switch the action of the radio. I have a 3 position key switch that drives the relay coils. In position 1 the radio follows the ignition, when the vehicle goes off the radio goes off, After the vehicle is started the radio comes on. in position 2 the radio is in valet mode and has no power applied to any of the radio. In position 3 the radio stays on regardless of the ignition switch.

Most of the time its in position1, If the vehicle is in for service position 2 and if I am going to be using the radio for a period of time with the vehicle off it will be in postion 3, I do a number of ARES/Skywarn events and spend several hours with the car off and radio on.

Dont forget you need fuses on both sides of the vehicle firewall.

 

[DaveInDenver]

It's true that most switching power supplies deal with the ripple produced by your starter, but it's not necessarily doing much good for them. The starter motor in our trucks is not a very friendly design w.r.t. noise and so my decision was that it's better to just switch the radio off while starting. I really like the double throw switch idea, that makes a lot of sense. If the radio does not use a switching supply (like most CBs), then it's actually very bad for the radios to be connected when starting. YMMV, this is just my approach.

 

[eugene]

I'm running all my electronics off a second battery that is isolated from the main electronically (diode).
A few years ago we bought a Chrysler minivan not knowing they put a lot of mitsubishi parts in it and our first long trip the main wiring harness burned in half so we had no power to anything and had to walk to use a phone (was early days of car phones when they were powered by the vehicle). So since then I've ran two batteries so my electronics can run independent.

 

[RoundOut]

I have not purchased my mobile yet, but I love the solution "Gary in Ohio" installed. That would allow one to leave the radio on for use as a crossband repeater while they hike within a few miles of the vehicle, allowing extended range from one's HT. No other vehicle electronics would drain power that way.

:clapsmile

 

[k6uk]

I've been running radios for many many years, and have never had a problem with a radio being damaged in this way. I do have all of my electronics switched via a solenoid currently, but for other reasons.

That being said, I have heard of Alinco radios losing their memory settings during engine cranking.

-Mike

 

[cruiser guy]

Dont forget you need fuses on both sides of the vehicle firewall.

Why both sides?