Recently , due to the new engine designs , cab creature comfort items , (if improvements are not invented/ found ); I am afraid CB's will only be useful for EXTREME short range communications. The new engines , fuel pumps , inverters, digital dash information centers are creating so much RF that the CB is almost useless. The new truck manufacturers are telling drivers they will just have to "live with it! " Any ideas out there to combat the interference?? For me , & I'm no tech installs are turning into "snipe hunts " for electronic interference !
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Something to work on , for the experts
- Thread starter Chainsawgang
- Start date
Get a ford Model T and keep it alive?
This is one of those deals where each noice source will have to be located and filtered, or enough people gripe to the FCC about the problem to have something done on a federal level.
This is one of those deals where each noice source will have to be located and filtered, or enough people gripe to the FCC about the problem to have something done on a federal level.
The best thing is to do as DTB suggests and eliminate the noise source. However, that is not always practical. One thing that does work pretty good is to use a DSP speaker with the radio. You'll be surprised how much engine noise it will filter out. They're not cheap, but it's a workable solution.
Modern cars/trucks aren't really any more noisy than they were a couple of dozen years ago. That noise is just coming from different places/sources. Sure, it's a bit harder to find that noise (sources) now, but only because those new sources are 'new'. Until the manufacturers are forced into 'curing' that problem(s), the only way to go about it is for the radio user to do so. Same thing for any 'new' thingy that causes problems. The only 'bad' part about it is if you happen to be in that 'new' stage of development. It will get better. If 'CB' radio was the only thing affected by this 'new' noise sources, forget it, ain't gonna happen, it's an 'un-licensed' service, doesn't have any particular protection from anything. But 'CB' radio isn't the only service being affected. Some of those 'services' are 'licensed' and those are the ones the FCC pays attention to (and no, I'm not talking only about ham radio). Hate to say it, but that 'beach', whine, and complain thingy is whats going to make a difference.
- 'Doc
- 'Doc
Moleculo said:
IMHO that is not really the answer either. I have a radio with builtin DSP and all it does is mask the audio noise and does nothing for the signal buried in the noise. If the noise is S-8 then it still takes a signal stronger than an S-8 to be heard no matter how good your DSP unit is.If you are fortunate enough to have a rig with IF DSP rather than audio DSP then it does help even more but those rigs are only found in some of the latest HF rigs. A DSP speaker may make things a bit better but you still need a strong signal to overcome the noise level.You will NEVER hear an S-5 signal under an S-8 noise level.
I disagree a bit, QRN. I run two dsp speakers in my mobile...one with a 706mkiig (built in dsp isn't very good) and one with a cb. I was shocked at how well the dsp speaker can get rid of alternator, ignition, and even a lot of fuel pump noise to allow otherwise unintelligable stations to make it through. Before curing the fuel pump noise, the dsp speaker was really the only way you could hear another station on the cb that wasn't S9. I know it sounds fishy, but it really does work. Obviously the best way is to cure the source, and if you have too many sources, the dsp speaker won't be able to get rid of them all, but it certainly won't hurt.
moleculo,
I'm not familiar with those speakers, can you recommend a good DSP speaker brand for CB & where I might could purchase one?
When I drive it is usually a "slip-seat" situation , filling in for another driver & it is just NOT practical to go on a RF noise witch hunt in every vehicle I drive . If I took that much time with every vehicle I might not ever get back ! LOL
I'm not familiar with those speakers, can you recommend a good DSP speaker brand for CB & where I might could purchase one?
When I drive it is usually a "slip-seat" situation , filling in for another driver & it is just NOT practical to go on a RF noise witch hunt in every vehicle I drive . If I took that much time with every vehicle I might not ever get back ! LOL
Tell me about it! I have been chasing this problem for almost 2 years now.
I actually got into and higher mileage Peterbilt ( same yr. and engine ) because it had half the RFI.
Well as it turns out the engine also had an air to air leak causing a loss of power and manifold pressure. At first it was minimal then it got much worse. Got the leak fixed and guess what? Yup same amount of RFI as the first rig.
Anything over 20 lbs. manifold and the RFI starts. This newer Cats engines in stock 475hp can show 50 lbs. Or say 5 S units worth.
And yes as Doc. stated RFI is much more prevalent nowadays. I have been driving commercially for 30 years and I have seen the increase. especially in the last 5 years.
I have tried alot of things, foil, chokes etc. Nothing has helped.
I have heard of guys really spending alot of time on this with no results.
Yup Caterpillar looks and says we haven't heard of any problems, it must be your install or radio. F them.
I actually got into and higher mileage Peterbilt ( same yr. and engine ) because it had half the RFI.
Well as it turns out the engine also had an air to air leak causing a loss of power and manifold pressure. At first it was minimal then it got much worse. Got the leak fixed and guess what? Yup same amount of RFI as the first rig.
Anything over 20 lbs. manifold and the RFI starts. This newer Cats engines in stock 475hp can show 50 lbs. Or say 5 S units worth.
And yes as Doc. stated RFI is much more prevalent nowadays. I have been driving commercially for 30 years and I have seen the increase. especially in the last 5 years.
I have tried alot of things, foil, chokes etc. Nothing has helped.
I have heard of guys really spending alot of time on this with no results.
Yup Caterpillar looks and says we haven't heard of any problems, it must be your install or radio. F them.
Try www.amcominc.com/, or type in "DSP Speakers", OR "ClearSpeech Speaker" in Google. They are expensive, but they work! Perhaps one will work in your application.
73
Gadfly
73
Gadfly
The only two that I know of that are readily available are the Gap "Hear-It" speaker and SGC's ADSP2 speaker. The Clearspeech speaker isn't available anymore, but you can occasionally find them on ebay for much more than they're worth. I have both the SGC and the Clearspeech and like the Clearspeech better. The SGC is OK, but the volume on the speaker isn't very good. In fact, I ended up taking the guts out of that and putting it in a Texas Ranger speaker so I now have the loudest mobile DSP speaker on the planet! I just ordered the Gap speaker as I've got a ridiculous noise level in my RV that I haven't been able to successfully track down. I'll let you know how effective it is when I get it.
Moleculo said:
I have said many times in the past that If I had to make a
choice between my amps or my ClearSpeech speaker then
the amps would have to go !!
What good does it do to be heard around the World and not
be able to hear across the street ?
Its a shame that Bob Heil bought the rights to manufactor
the speaker, then did not do anything with those rights as
far as I know...
With all due respect to Bob who is also a business man, I am
sure his reasons are valid.
That said not eveyone will like it, but given some time you
will learn to love it.
NO, mine is not for sale.
Best Regards,
John
Look what I just found today...does this look familiar? 
http://www.westmountainradio.com/CLRspkr.htm
I knew that Heil had the rights to ClearSpeech, but discontinued it. It looks like someone else picked it up and has a new product! Their price is too, high though. Their competitor's are all around $150.
http://www.westmountainradio.com/CLRspkr.htm
I knew that Heil had the rights to ClearSpeech, but discontinued it. It looks like someone else picked it up and has a new product! Their price is too, high though. Their competitor's are all around $150.
DXman
Yes, that's 3100 degrees F. Nine yrs of hard work.
I bought one of the older versions ClearSpeech Speaker (the one on the E-bay link above) and I have it in my truck - will never part with it (unless it is stolen).
I do believe I bought it from a forum member here a couple years back.
I also have the Heil ClearSpeech for the base, it works great and I have never regretted paying $200 for it.
I do believe I bought it from a forum member here a couple years back.
I also have the Heil ClearSpeech for the base, it works great and I have never regretted paying $200 for it.
I have a couple of pennies worth to throw into this one, if you don't mind.
My experience is that most of the noise in vehicles is not actually RFI--it is power noise. Yes, there is some RF, but it is the exception.
Although tracking down and filtering the noise source is best--it isn't always practical or easy.
To combat DC power noise at the radio, there are two things to try:
1 (Most important!) Run your radio's power leads straight to the battery. Well, straight from a fuse installed directly at the battery, anyway.
2. Filter the DC power as close to the radio as you can. I built a two-stage LC network in a fairly small project box, and have it connected about 6 inches from the radio.
I have a toroid inductor form, with 30 turns of #12 wire on it.
Snap-Together Toroid Choke Core-2-Pack, Radio Shack part number 273-104.
You want the inductor first, to limit the inrush current to the capacitors.
Then a 2200 micro-farad electrolytic, 50WVDC.
4700µF 35V 20% Axial-Lead Electrolytic Capacitor, Radio Shack part number 272-1022.
Repeat each of the above for the second stage. The inductor core comes in a 2-pack anyway.
Mount it all in a plastic box:
Project Enclosure (7x5x3"), Radio Shack part number 270-1807.
Run power in, put four sets of binding post/Banana jacks on one end, and power your radios (and stuff) from there.
I also put a 7 amp fuse in a panel mount holder and a power switch, just because they were laying around.
Not as good as elimnating the noise at the source, but it works for me. Any radios I use in the Jeep are powered through this filter.
Incidently, the noise is not new. My Jeep is a 1989 Cherokee--with computer controlled engine and transmission, multi-point electronic fuel injection, and a distributor for spark. the vast majority of the noise is on the DC system, and this filter helps a lot! I go from S6 noise on 10 and 11 meters to about S2, which I can live with.
Dave_W6DPS
My experience is that most of the noise in vehicles is not actually RFI--it is power noise. Yes, there is some RF, but it is the exception.
Although tracking down and filtering the noise source is best--it isn't always practical or easy.
To combat DC power noise at the radio, there are two things to try:
1 (Most important!) Run your radio's power leads straight to the battery. Well, straight from a fuse installed directly at the battery, anyway.
2. Filter the DC power as close to the radio as you can. I built a two-stage LC network in a fairly small project box, and have it connected about 6 inches from the radio.
I have a toroid inductor form, with 30 turns of #12 wire on it.
Snap-Together Toroid Choke Core-2-Pack, Radio Shack part number 273-104.
You want the inductor first, to limit the inrush current to the capacitors.
Then a 2200 micro-farad electrolytic, 50WVDC.
4700µF 35V 20% Axial-Lead Electrolytic Capacitor, Radio Shack part number 272-1022.
Repeat each of the above for the second stage. The inductor core comes in a 2-pack anyway.
Mount it all in a plastic box:
Project Enclosure (7x5x3"), Radio Shack part number 270-1807.
Run power in, put four sets of binding post/Banana jacks on one end, and power your radios (and stuff) from there.
I also put a 7 amp fuse in a panel mount holder and a power switch, just because they were laying around.
Not as good as elimnating the noise at the source, but it works for me. Any radios I use in the Jeep are powered through this filter.
Incidently, the noise is not new. My Jeep is a 1989 Cherokee--with computer controlled engine and transmission, multi-point electronic fuel injection, and a distributor for spark. the vast majority of the noise is on the DC system, and this filter helps a lot! I go from S6 noise on 10 and 11 meters to about S2, which I can live with.
Dave_W6DPS
There are some commercial (radio shack, magnum) inline power filters you can buy that are basically the same thing. But it would be far cheaper and more fun to build one yourself. Dave...you should take a pic of the inside and post it. A lot of people need to see the visuals....