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Rx audio through a car stereo?
- Thread starter thercman
- Start date
yeah i tried it. its hard to remember but i think it wasn't a success with me as i was using a power mike and the squelch wouldn't fully mute the audio so there would be a feedback squeal whenever i keyed up. also i couldn't listen to the stereo and cb at the same time. the trouble with audio amplifiers is similar to the trouble with rf amplifiers, i.e the more amplification then the more distortion. i can always tell when someone is running a rf amplifier as their signal quality degrades a little over a barefoot rig. for my homebase on weak signals i have far better results running a large speaker directly from the radio as an external speaker. i have read that large speakers take less power to drive them than tiny ones so that seems to be the way to go for the best clarity.
RX audio through car speakers is easy as pie. TX audio through speakers is tougher to do. You need to have a radio with a monitor function. However, if you pump that through the car speakers, you're going to get all kinds of feedback. You would have to keep the mic gain really low and the speaker volume really low to get it to work. Obviously, that kind've defeats the point.
Wanna bet?
A properly run amp will not be noticeable from a barefoot radio. An overdriven amp will be noticed as will a class C piece of crap but again a properly run and properly biased amp will not be noticed. Provided of course any fans running are not picked up by the microphone.
I don't know what either of you are thinking but I do know that it's a well known fact that many cb'ers spend good money to get their radios modified to transmit on more than 40 channels simultaneously and judging from your comment "wanna bet" you seem to think that the latest and greatest amplifiers can preserve or improve audio modulation when any competent cb'er can tell you that expensive amplifiers contain bandpass filters that present a high swr to harmonic frequencies of transmission and so degrade the signal that is transmitted.
Well since this was posted in the Ham section, naturally I thought we were talking about certified ham equipment.
That might be a competent radio op, but not a knowledgeable one. That bold statement isn't accurate at all.
That is not what bandpass filters accomplish and they certainly don't degrade the intended signal.
Here let me try to explain:
A bandpass filter does just that - filters out or reduces the output power of the RF that is not within the intended pass band width. SWR doesn't really have a play in the equation, either. The reason you need to add filtering is because of the way the amplifier works, it tends to create rf harmonics that weren't in the original input signal. We need to get rid of those because they are harmful to other bands.
Think of it like this: If what I input into the amp is "A" and what comes out is "A" + "B" + "C", we need to filter out "B" & "C" to we're back to just tranmitting "A". That's not degradation, that's cleanup. Now substitute "2nd harmonic " for "B" and "3rd harmonic" for "C" and you start to get a clearer picture of what we're talking about.
That might be a competent radio op, but not a knowledgeable one. That bold statement isn't accurate at all.
That is not what bandpass filters accomplish and they certainly don't degrade the intended signal.
Here let me try to explain:
A bandpass filter does just that - filters out or reduces the output power of the RF that is not within the intended pass band width. SWR doesn't really have a play in the equation, either. The reason you need to add filtering is because of the way the amplifier works, it tends to create rf harmonics that weren't in the original input signal. We need to get rid of those because they are harmful to other bands.
Think of it like this: If what I input into the amp is "A" and what comes out is "A" + "B" + "C", we need to filter out "B" & "C" to we're back to just tranmitting "A". That's not degradation, that's cleanup. Now substitute "2nd harmonic " for "B" and "3rd harmonic" for "C" and you start to get a clearer picture of what we're talking about.
My first instinct was to post "BULLSHIT!" but I decided to hold back after I read your next post. :laugh:
I have done this in my truck using a cell phone adapter that outputs on the FM band. A cell phone unit has restricted audio response on the low end by design.
A standard I pod FM unit transmits in steieo but used with the correct adapter or cable to change to mono also work quite well otherwise you only hear out of one channel or not at all..
It's 'possible' to hear some small amount noise from the FM receiver when transmitting due to the FM receive antenna being so close to the transmit antenna that the adapter cannot full quiet the FM .
Good luck.
A standard I pod FM unit transmits in steieo but used with the correct adapter or cable to change to mono also work quite well otherwise you only hear out of one channel or not at all..
It's 'possible' to hear some small amount noise from the FM receiver when transmitting due to the FM receive antenna being so close to the transmit antenna that the adapter cannot full quiet the FM .
Good luck.