How to select antenna for CB?

True statement given that the antenna's groundplane is the car's body. You are matching the antenna to its situation on the vehicle so it does not damage the transmitter so non-technically speaking, you are matching the antenna FOR the reciever.....as far as I remember

 

i have to agree some of the facts you brought to the table, Higher frequencies experience the most dramatic increase of signal strengths, while on low-VHF and HF the effect is very little to none.
AM = Ampitude modulation (skip) (Cb radio (27 megahertz) was intended not to skip, but often it does skip.

Skip becomes stronger and weaker according to an 11 year solar cycle.


FM= Frequency modulation (E-skip)

"TV DX and FM DX are two terms, customarily grouped together, that refer to long-distance reception of TV and FM radio stations, respectively. The term DX is an old telegraphic term meaning "long distance." These terms refer to the active search for distant radio or television stations received during unusual tropospheric lower atmospheric weather-related, or E-layer and F2-layer upper atmospheric ionospheric conditions" <<- that is what i was talking about


"and BTW an AMP causing 'Damage' to your equipment is caused by not calibrationg the RF between your antenna and radio, so when you transmit, power is kicked back in to your radio and the finals are eventually fired"

I think the word your looking for is Standing Wave Ratio(SWR)
NOT RF ??And yes one should have an SWR of 1.5:1 Max otherwise you can run the risk of damaging the final output stages on your radios circuit board.Not to mention horrible reception/transmission quality.

I have seen the ends of a dipole antenna arc,spark and cause a fire.
But what do i know... I have only built and tested more RF transmitters than you've probably used in your life


There are several types of RF burn






First of all (READ) i didn't say a good ground causes rf burn
i said the human body makes a good ground

Basic physics

The "perfect transmission line" operates in free space, with nothing around it. The fields around the conductors don't radiate (that's why it's a transmission line, not an antenna), but they are not zero. Close to the wires, the fields are strong.

If you put your finger near two wires carrying RF whether the currents are balanced or not some of that RF is going to induce currents in your finger. If you touch the wires, some of that RF will flow through your finger.

It doesn't matter low voltage / high current, or high voltage/low current. There's power there, and it will be happy to burn you. Flesh is a pretty good conductor of electricity and your body if grounded will make a good ground, hence causing a typical "RF burn"
Now if you stand in front of a feed horn on a transceiver parabolic dish you could (with enough energy) literally cook a chicken with the RF energy in the field!


"just because your a prude and scared to use an AMP dosen't mean everyone else has to follow what you think, Mr. Flawless driver, LMFAO!!!!"


okay i can see your point, Although i wouldn't call my "Flawless driver" statement prudent. I could how it could be misconstrued that way. i was asked a question and i answered honestly, I in fact have never had a moving violation nor accident.I accredit this to me not speeding, ignoring traffic laws and me driving defensively. Having been a volunteer Firefighter the past two years i think seeing people harmed/killed in accidents where it was clear that the person who caused the accident was
either in a hurry (speeding) or failing to follow traffic laws. this just gives me more of a reason to slow down, be aware, and drive defensively. You can call that prudent or whatever you want but I have a flawless driving record and i like it that way.


And yes I am way to scared to use an amp........ LMFAO!!!

 

This might be a stupid question, but is it feasible to mount an antennea to my bumper? I have a magnetic mount on my roof, but it sticks up about 5 feet and looks gaudy as hell. I'm also interested in more info about SWR and tuning my CB. I have a handheld with a 5' antennea but I don't really know how to use what equipment I've already got.

 

I've seen a lot of people mount their antenna to the bumper over on TTORA.

I have my antenna mounted to the bed rail in the back right corner and grounded to the frame. Then the coax is routed under the truck and through the hole in the floor under the passenger seat. I have some pics in my build if anyones curious. I still need to tune the antenna though.

 

Does anyone know if/how I could use an aftermarket antenna for both stronger FM reception and use it as a CB?
Is this possible?
I’d like to replace my stock antenna and get an antenna that’s around 2ft.
I’ve looked on the Hamm website a little, but unsure about this and wattage.
I’d like to eventually get a CB but only use one antenna.
Thanks in advance

 

not sure it's possible... FM radio stations are 88.1 to 108.1 mhz while CB radio are 26.965 to 27.405 mhz or something like that...

i have seen antennas ranging from 30 to 108mhz, but that falls out of range for CB... someone more knowledgeable will chime in, but i wanted to do the same thing but have never been able to figure out if it can be done..

 

Thanks for the info...really appreciate it...kinda new to this, but if possible I’d like to only have one antenna and get better fm reception.

 

Like Mike stated well, you cannot combine those two bands-one's designed for AM/HF transceive and one's for FM/VHF receive. You need a second dedicated antenna for CB because you're transmitting and need a tuned antenna for that.

 

Thanks for the info!