Ignition noise from K40 antenna

[mmckenna]

As has been suggested here, he directly wired the power supply to the radio via a dedicated line to the battery. He's also familiar with bonding and grounding.

Make sure the body of the radio is grounded to the chassis. Do not rely on the long negative lead to the battery, or the coax shield. Long conductors can act like antennas.
Run a ground wire/strap from the radio chassis to the vehicle ground, keep it as short as possible.

I get the fact that a properly installed antenna is key to good RX and TX with any radio, either CB or HAM, but getting maximum performance requires attention to detail and getting everything just right.

Yep, and now that you get it and see how it helps, you can watch the threads on this site and read about those that insist on cutting corners on their install then get frustrated when it doesn't work well. Taking the time to do everything correctly the first time saves a lot of headaches.

7 miles isn't bad, as it can really be dependent on atmospheric conditions, local conditions, terrain, etc.

 

[iMONITOR]

You may have arcing in the ignition wires or distributor.

It's been a long time since I've seen a 'distributor' under the hood of any vehicle!

 

[FiveFilter]

QUOTE: "...Unfortunately for the consumer, the CB radio industry has done a disservice by making users think that plugging into the cigarette lighter plug and dropping a mag mount antenna on your roof is all you need to make it all work. It's not..."

Well, sometimes the CB industry is right. At least it has been for me.

I've got three vehicles I use a CB in during various trips:

An F250 pickup with a Midland 1001Z radio with a 62-inch mag-mounted Wilson 1000 antenna for travel trailering around the country;

A Jeep Wrangler with a Cobra 19 DX IV radio and a 35-inch mag-mounted K30 antenna for hunting in the boondocks;

And a Mazda3 sedan with a Uniden 520 XL radio and a 55-inch mag-mounted Wilson 500 antenna for long road trips.

I guess I'm lucky, as in each of these three cases, I simply plug the radio into the 12V ports and stick the mag mounts either on the roof or, in the case of the Jeep which has no metal roof, in the center of the hood. I have experienced no interference and excellent performance from each of these rigs.

So, the CB industry is right some of the time. For me, I've been blessed with a batting record of 1000 so far.

 

[mdouble]

Thanks again for your help it is much appreciated. Grounding the radio to the chassis via a short lead makes sense to me. I'm working out ways to make all the connections plug in and out types so I can remove the radio when I want to. I live in southern Ontario, Canada and we can have temperature swings from -40 C in the winter to +40 C in the summer, which is brutal on people and equipment. I bought the new President McKinley because it's small and portable. In spite of being an SUV, the Suzuki has very little room for a CB, so mounting is something of a challenge. As I mentioned before, I am currently studying for my HAM radio license, and I recognize that HAM radios offer many advantages over CB. My point in getting a CB in part is to build a multilayer communications network which can integrate a local unlicensed network of users with licensed HAM operators. This will allow for the broadest possible coverage for local and long distance communications. When used in an organized network CB can also cover a respectable distance, excluding the unreliable nature of DX / skip. I have taken this approach because not everyone will have an interest in being a HAM, but might use CB in an emergency situation because it's generally cheap and simple, and requires no license.

 

[Brojon]

Found this thread because I have the same issue with a minty fresh Midland 75-822.
I've been wanting a CB to pop into our 2017 Honda CR-V and ordered from Midland via Amazon.
Got it today and imagine my dismay when I fired up the radio and got an earful of ignition noise.
Revved the engine to verify it was indeed the vehicle that was causing the noise.
Now I'm trained in RF systems courtesy of USAF and my dad taught me auto mechanics as he was a professional and then I've owned radios on and off since the 70's CB craze.
So I'm not a rookie. First thing I did was disconnect from the power/antenna adapter and reinstalled the battery pack and rubber ducky antenna.
Guess what - I still have the noise.
Seems unlikely that a new vehicle would be unsuppressed but here we are.
I was hoping to get feedback from someone who has one of these things to tell me if it's just susceptible to vehicular shot noise.

 

[FiveFilter]

Since the noise is continuing even with a separate power supply and antenna, it must be coming in through the air into the antenna. Modern vehicles have computers and lots of other electric components including LEDs that can produce a lot of RF. I'd try putting an RF choke on the antenna coax to see if that helps.

 

[Brojon]

Since the noise is continuing even with a separate power supply and antenna, it must be coming in through the air into the antenna. Modern vehicles have computers and lots of other electric components including LEDs that can produce a lot of RF. I'd try putting an RF choke on the antenna coax to see if that helps.

This is definitely ignition noise.
Update - I think there's something wrong with this unit - just touching the antenna connector causes a large jump in signal and drop in noise. I'm going to send back and try again.

 

[Rred]

"lots of other electric components including LEDs that can produce a lot of RF."
A common misconception. LEDs never produce a lot of RF. Technically since they are diodes they can produce some "diode noise" but you'd never notice that.
What does produce RF, as the LED controller circuits. LED taillights are typically pulsed at high frequency, so they appear "dim" when the tail light function is turned on, and "bright" (longer and stronger pulses) when the brakes are used.
But plain dumb LEDs that are just powered on or not, produce no RF, although there may be a noisy voltage regulator driving them.

 

[Brojon]

"lots of other electric components including LEDs that can produce a lot of RF."
A common misconception. LEDs never produce a lot of RF. Technically since they are diodes they can produce some "diode noise" but you'd never notice that.
What does produce RF, as the LED controller circuits. LED taillights are typically pulsed at high frequency, so they appear "dim" when the tail light function is turned on, and "bright" (longer and stronger pulses) when the brakes are used.
But plain dumb LEDs that are just powered on or not, produce no RF, although there may be a noisy voltage regulator driving them.

I'm positive the noise is ignition since it revs up and down with the engine.
Just got off the phone with Midland and they agree t sounds like the unit is bad - they say I should never get that kind of noise - especially with batteries and rubber ducky.

 

[mmckenna]

I'm positive the noise is ignition since it revs up and down with the engine.

Ignition and alternators will do that.

Just got off the phone with Midland and they agree t sounds like the unit is bad - they say I should never get that kind of noise - especially with batteries and rubber ducky.

I'm impressed. I'm impressed that a company will still provide that level of support for a consumer product. That's good to know.