CB Radio

Tell me more where you physically put the radios and how did you route the antenna cable(s). I would carefully consider where I route the cables in case your antenna goes back and back emf lights up the braid.

Tx
Don, WA7FM

 

I have a FT-8800 Yaesu, (NFM) and the body is in the pocket at the back of the car trunk on the drivers side, fits quite nicely there. The control head is mounted above the rear view mirror, and the mic fits in the drop down pocket in front of the mirror. The antenna cable is routed through the hatchback into the wiring channel and into the pocket area where the rig is placed. I drilled a small hole on the side of the hatchback and mounted a trunk lip mount, a Diamond K-400. Gives me good grounding, I also added a extra piece of RG8 braid from the hatchbach ground to the carbody ground. I also strapped a piece of braid from the hood to the car body effectivly grounding the front hood very well. All proper RF procedures.

Now as far as CB goes, since it is an AMPLITUDE Modulated signal you are going to hear every pulse your car puts out. Its just the nature of the beast. As WA1HOG says, get a unit with an EFFECTIVE noise blanker and this might help reduce some of the electrical noise our Prii make! Remember the better the antenna, the better the system. Cheap glass mounts, while they may look "COOL" have crappy VSWR results. Mag Mounts are better, and something that attaches to the car and actually grounds itself would be the best, like the K-400 or (shudder) drilling a hole in the car and mounting a roof mount system. Since you are limited to 5 watts of RF power, a bad VSWR, while not a good thing, is probably not going to have enough RF to cause problems, it will affect how much ERP, Effective Radiated Power, you will actually be outting out! Ferrite beads might help suppress the RF, but it will not help with the impulse noise!

Good Luck de Pat KK6PD

 

This statement is a bit confusing...please clarify what you mean by "RF" (wanted RF power, unwanted RF interference, etc...).

On the contrary, 5W under high VSWR will crawl on the shield of your coax and it can definitely cause problems depending upon where the coax is routed and what is being affected. Had I not seen this with my own eyes on the bench, I would think it could be ignored as well. I did not notice any attenuation of the RF signal by clamping on a few ferrites around the coax.

 

RF = RADIO FREQUENCY
VSWR = THE AMOUNT OF RF ENERGY REFLECTED BACK DOWN THE FEEDLINE INTO THE OUTPUT OF THE TRANSMITTER, vs THE AMOUNT OF POWER RADIATED BY THE ANTENNA!

If you have that much reflected power with a 5 watt output that it causes severe problems, then,
1- either you have the completly wrong antenna, or
2- the installation was so poorly done, or
3- proper RF practices were ignored, I.E tuning the antenna to match the frequency you are transmitting on.
you probably should'nt be fooling around with transmitters

If you want, the ARRL puts out a book called "The Radio Amateurs Handbook" it is the bible to all things RF and radio related. I would go out and purchase a copy and read it. It is a wealth of information, and if you read and understand, nay, comprehend what you read, you can have a system that will work properly, no matter if its 2 meters, buisness band, CB band, microwave.

Part of my profession is RF systems installation. Repeaters, mountain top sites, tower installs, vechicle installations. There are proper RF procedures that have to be observed if you are ever going to have a hope in hell of getting a usuable RF signal into the air for others to receive!!!

Doing things in a lab and doing things in real life can be apples and oranges. I have been doing this type of work for over 40 years.

as you say ..
"On the contrary, 5W under high VSWR will crawl on the shield of your coax and it can definitely cause problems depending upon where the coax is routed and what is being affected."

This statement would lead me to believe that if you have that much RF floating around, there has been a really terrible job of installing the radio in the first place!!!

That is why Amateurs have to take a basic test to at least test the operator on "Proper RF Procedure" Its not guesswork, its a science, not VOODOO!!

Black Arts, They pays well!!

73 de Pat KK6PD

 

Sorry to be short tempered with you, but your response was all over the place and a bit condescending. I was just asking for a clear explanation of what you were trying to say, which you could have answered in one or two sentences, but did not. With 40 years of experience you ought to be able to write technically meaningful statements. Also, I'm not interested in your critique of my lab experiment, which you do not understand, or what you think I should or should not be fooling around with.

What you are talking about is a high power professionally designed fixed installation, which is installed by a trained professional technician with the proper equipment - much different from a CB radio in a Prius installed by an individual with no test equipment, little RF knowledge and no information about the systems involved. Without test equipment, even a pro can only try this, try that and see what works.

If we all pitch in our ideas and share information and results, maybe we'll come up with a solution - or maybe we'll find out that a Prius is a really good RF noise generator. It would be interesting to put a spectrum analyzer on a Prius mounted CB antenna....

 

One of the radio engineers where I work indicated that the Prius may be exceeding FCC regs on EMI emissions. He said the best way to reduce the noise is at the source, but we are dealing with mucho thousands of watts of power in the Prius motor/generator/electrical subsystems. A little 2 Amp RF choke isn't going to cut it. CBs and Prius may be like trying to mix oil and water. Not impossible, but without a little know-how, very difficult. I don't give up easily and will keep plugging along getting educated along the way. Thank you all for your assistance.

 

Hi all, PD8F here. I usually put my Kenwood on the passenger seat and stick a small magnet combi-antenna for 144/430 MHz on top. But this way the windows remains open and this situation is not ideal.
Best would be to fit the trx somewhere permanently in the car. The problem is the antenne. Are there antennas available for the Prius (Comfort 2006) that will work on 2m, 70cm and FM radio as well? With a signal splitter or somezhing like that?
I don't want to void the warrenty so I have to avoid modifications to the vehicle as much as possible.

I usually work the local 70cm repeaters only so a combination 430 MHz and 100 MHz antenna would be acceptable. Hope you have some suggestions.

73, Floyd

 

MANY post ago in this thread, there is a note that there is a signal amp in the antenna line, effectively ruling out on the AM/144/430 splitters. Transmit down it and it goes thru the amp, probably ruining it. There are window mount antennas, that aren't terribly effective, but for repeater work probably OK!!! Very near the beginning of this thread is a very nice article about building a mount that fits where the hatch support is attached to the car body. A very good idea, involving good grounding of the antenna to the body, etc. I for several years used a very small magnetic antenna. The base is about the size of a small coin, it mounted on the front of the car just forward of the rear view mirrors, cable into the vehicle to the radio...in the US they are only about $25, so inexpensive. They handle 50 or so watts on 2/440! It worked quite well for me. From reading here and eham, powering the rig, RF interference and other noise is going to be a problem. Post here on how you make out...I just bought a 2009 and the FT817 is just sitting on the desk, waiting for an install.

 

Sorry, hadn't found it yet. Registered today on this forum.

But thanks for the info Massman. I have an FT817 as well, might be a good idea to put that one in the car and get myself something new for indoor use. Only 5 Watts should be enough to work the repeaters, we have a good grid here... small country.

Thanks! Floyd

 

If you go to eham to the forums and look under mobile, there are several long posts about a fellow who has been working to install HF in his PRIUS for better than a year. The extent to which he has grounded, beaded, etc. Impressive, yet it only brings the noise down 2-3 S units. I guess our Prii are just noisy.

 

As long as it’s white noise we’re still in the environment friendly zone. But in the car I will probably only work the 2m and 70cm repeaters anyway so maybe I could install brackets so I can slide the Yaesu in and out easily. I’ll have a look on the eham website.

Thanks & 73, Floyd