Turbo Boost causes CB buzz

[JamaicaJoe]

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Also; How is the radio itself grounded and where are the power leads connected??

 

[LokiWolf]

Also; How is the radio itself grounded and where are the power leads connected??

Many of us have asked that. They don't appear to be able to answer that...yet we are blaming the "Turbo Boost Pump".

 

[LokiWolf]

NMO mounts are designed to be installed with a special hole saw that takes a bit of paint off of the roof right around the hole. The mount itself should bite into the paint if tightened enough. But unless that electrical connection is made there may be resistance in that connection. The clamp on the bottom also makes a contact, but if there is paint or rust beneath, there may be a poor connection. Some bit of dielectric grease can provide a weather seal on the rubber O ring and brass to prevent rust from occurring.

Still don't see the need to drill the roof in a modern vehicle for an antenna. Most newer large Fords are going Al, so makes even less sense. So many good antenna mounts out there.

 

[JamaicaJoe]

Still don't see the need to drill the roof in a modern vehicle for an antenna. Most newer large Fords are going Al, so makes even less sense. So many good antenna mounts out there.

Meh. NMO is the only way to go. You need an effective ground plane for a 27 MHz CB radio to operate properly. The center roof of a Ford Expedition is ideal for that. My new one is going to have at least FIVE NMO mounted antennas. I might add a couple more for future use.

 

[cmc3]

Meh. NMO is the only way to go. You need an effective ground plane for a 27 MHz CB radio to operate properly. The center roof of a Ford Expedition is ideal for that. My new one is going to have at least FIVE NMO mounted antennas. I might add a couple more for future use.

I created a crude wire "expedition" in xnec2c. Tried various whip placements. The center of the roof gets the best omni-directioal coverage. The attached simulations are for a wire loop on top of my roof box. It needs a little tweaking to get the match, but it has a nice broad band response. I also have a few loaded whip simulations, they then to be narrow band and tuning sensitive.

 

[LokiWolf]

I created a crude wire "expedition" in xnec2c. Tried various whip placements. The center of the roof gets the best omni-directioal coverage. The attached simulations are for a wire loop on top of my roof box. It needs a little tweaking to get the match, but it has a nice broad band response. I also have a few loaded whip simulations, they then to be narrow band and tuning sensitive.

That is awesome stuff! Looks like my Heat Map software! But, remember, there is no such thing as a Turbo Boost Pump...

 

[LokiWolf]

Meh. NMO is the only way to go. You need an effective ground plane for a 27 MHz CB radio to operate properly. The center roof of a Ford Expedition is ideal for that. My new one is going to have at least FIVE NMO mounted antennas. I might add a couple more for future use.

NMO is just a mount standard originally developed by Motorola. Doesn't mean you need to drill the roof. Clip mounts, hood mounts, 3rd Brake light mounts, my GMRS radio antenna is on a bracket off of my Billiebars. Yeah, probably not the best, but I haven't had any range issues, but it is attached to a Midland MXT500, so it pushes plenty of power.

Admittedly, I haven't had a CB in my Truck for at least 5 years. Use GMRS mostly even though I have a Novice License, have since I was a teenager.

Also, my 150 and my Expedition, both have glass for a roof, so that is no help. Also, my 150 is Aluminum.

 

[JamaicaJoe]

I created a crude wire "expedition" in xnec2c. Tried various whip placements. The center of the roof gets the best omni-directioal coverage. The attached simulations are for a wire loop on top of my roof box. It needs a little tweaking to get the match, but it has a nice broad band response. I also have a few loaded whip simulations, they then to be narrow band and tuning sensitive.

Outstanding! Can you model a 6 meter antenna centered forward between the CB whip and the windshield? Also curious about interaction if any.

 

[cmc3]

Outstanding! Can you model a 6 meter antenna centered forward between the CB whip and the windshield? Also curious about interaction if any.

I'll give it a shot, once I get back to the simulator.

 

[cmc3]

A little update to my CB noise investigation. I found the radio "noise blanker" settings were suppressing some of the noise. Once disabled, the noise appeared to be plain engine ignition noise. A RPM related buzz. I pulled all the plug coils, scrapped corrosion and made sure all the coils and connectors were seated and snugged correctly. It helped a lot. But there is still a bit of a RPM related buzz. It doesn't appear to be coming over the 12V. I ran the radio on a separate battery with the engine on and off...no difference. Next up is to check the antenna grounding and coax connections.