| Author |
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Biged
| | Posted on Thursday, April 04, 2002 - 3:50 pm: | 
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The big question I have is to leave the limiter in or take it out. Let me explain why. All of my radios have been clipped up until now. I just purchased a Uniden PC78xl, and I took it to my local tech to have a turbo board put in it. While he was inside the radio he noticed it hasnt been clipped. He asked me if I wanted it done and I told him no. Then within a few minutes of explaining why I should clip it, he convinced me to do it. Last night I got curious. I hooked the radio up to my Dosey and checked the modulation and it was about 125%-130% with the limiter out. I put the limiter back in it and then checked the modulation again and compaired the two. Not only did the modulation drop but the meter would swing up to about 110% then fall back. I believe this is called "clipping". I then hooked up a second radio with no antenna on it so as I could here if there was any difference on the recieving end. I could not tell the difference. Now I know that the Dosey meter isnt the most accurate meter and that removing the limiter will cause splatter so as the meter will show more modulation. And also not noticing any audio difference in the recieving end. Why does everybody advocate removing the limiter? For somebody who just wants to make his radio sound a little better takes it to the CB shop and they charge you $20 to snip a wire, this is a good deal. The costomer doesnt know what is accually going on. However, when the tech is finished, he hands you your radio back and takes your money and doesnt show you the difference on the meter. You just take his word for it. Now, my question is, why do all the radio shops advocate removing it if it doesnt make a difference. |
Parkcom
| | Posted on Thursday, April 04, 2002 - 5:48 pm: |
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hello big it depends on the radio some get much better audio then others when clipped some times before the tech clips it he will turn up the vr ajustment in the radio before he clips it what is the same thing as clipping it alot of times they do both if he did that first you would not see a difference when you returned the clip . some radios have no swing unless clipped some radios come right out of the box with low audio another reason with all that said some people beg for the clipper back because they never sounded so crisp and clear as they did when they had there clipper for the most part i would say leave it in and get a power mike and its a better chace of having a very clean sounding station oh yea get a new tech you guy need some manners most will show you the difference before you leave the shop goodluck |
jyd
| | Posted on Thursday, April 04, 2002 - 5:53 pm: |
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uniden are usually ok when you clip them d-11 is yours,if you dont like it or have bad reports put it back. |
Barakuda318
| | Posted on Thursday, April 04, 2002 - 8:38 pm: |
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I believe that it is just a very easy way to make money, and bad for your radio at the same time, The only real difference that it makes is the spuriouse emitions, and that is bad, just turn up the vr pot for modulation back it off just a hair and there you go, very loud and safe, the clipping can overdrive the audio ic and therefor really truely make your radio smoke,,, not a good deal if you ask me,,,,,,jmho....
73's |
Taz
| | Posted on Thursday, April 04, 2002 - 10:06 pm: |
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DONT CLIP ANYTHING, IT CAUSES HARMONICS AND SPURIOUS EMISSIONS AND PROBLEMS WITH THE NEIGHBORS! The tech just dosent know better. Your radio is not capable of going over 100% mod without it clipped. With it clipped you would be lucky to get 120%. YOUR RUNNING YOUR RADIO AT A BASE, AND HE WORKS ON MOST RADIOS FOR DRIVERS AND DRIVERS DONT HAVE TO WORRY ABOUT TEARING THEIR NEIGHBORS HOUSE UP AND YOU DO, HE DOSENT KNOW BETTER. DONT CLIP THE MOD LIMITER ITS OVERMODULATION!
TAZ |
409
| | Posted on Friday, April 05, 2002 - 4:24 am: |
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Some radios come out of the box with such low modulation even a power mic won't help much. Many are set to begin clipping at 75 to 80% and no matter how much input you cram into the audio , you can't get 100% modulation. If you are lucky enough to have a pot. to adjust, you can raise the clip level to where you can at least get full swing. If not, then clipping the limiter is your only choice. If you use a stock mic. you don't run to much a danger of over-mod. like you would if you have a power unit. |
bruce
| | Posted on Friday, April 05, 2002 - 7:45 am: |
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ASIDE from the fact its ILLEGUAL the cliper is there to prevent the radio from exceeding 100% modulation not to limit audio. The cliper doesnt even figure in your radios audio till you get over 90 % so what the beef. A much better way to acheve a great sounding radio is to RF clip the audio this has been done for at least 40 years but is tricky and expensive and will not work on high level modulated am radios.The problem is the NEGITIVE 100% modulation not the positive one you can run 500% on the + side and sound realy loud but getting audio to do this is quite a trick. Back in the 40's and 50's when AM was king negitive peak clipers were common and with little or no splatter these guys routeenly had well over 100% mod and some are still in use today on classic and vintage radios. Ten-Tec sells a 15 dollar audio prosser board adding it to your radio is leagual and they sound good when set up right CBINT also makes one for about 30 bucks. Now if you want to sound good lissen to the AM boys on 80, 40 or 10 meters take a clue from them AM and good sounding audio is what they do best. |
Antennadude
| | Posted on Friday, April 05, 2002 - 6:58 pm: |
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Oboy here her goes again everything is iillegal. Gosh bruce give it a rest let the people do as they wish without you telling us that "its illegal" Please let the hobby go as it is your techcomments a well received but I for one get tired of looking at your "its illegal" posts
' |
707
| | Posted on Friday, April 05, 2002 - 7:38 pm: |
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One reason the modulation limits are there is to protect the channel spacing. Nothing wrong with making note of that, since at one time or another we have all complained about someone splattering all over the band. Also, nothing wrong with experimenting and coming up with a solution that is loud but still doesn't encroach on the guy one channel down who has as much a right to transmit there as anyone else.
Perhaps bruce gets tired of looking at all the "let's see how much I can destroy the hobby for others" comments. |
707
| | Posted on Friday, April 05, 2002 - 7:45 pm: |
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BTW, I'll be at NAB 2002 in Las Vegas next week looking at the BIG RADIOS and Mics. |
Taz
| | Posted on Friday, April 05, 2002 - 8:17 pm: |
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I dont care if he says its illegal. Its not because i dont respect what he says its that its not going to help. But can you blame him? |
Taz
| | Posted on Friday, April 05, 2002 - 8:20 pm: |
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And not only that it really is illegal. BUT THE MORONS WHO THINK ITS GOOD TO DO IT SHOULD BE BEAT CAUSE THEY DONT CARE and think they are cb rambos and dont know better |
bruce
| | Posted on Friday, April 05, 2002 - 8:53 pm: |
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is my statment incorrect?? |
Ohiobiker
| | Posted on Friday, April 05, 2002 - 9:11 pm: |
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Seems to me....If I get tired of looking at something....I look at other things...Bruce is just stating facts...he is not saying not to do these things I have never seen him say .."Don't do this it is illegle"...just just facts....to me if you read something and it tends to make you upset/angry or if you're just outright anoyed read else where. Theres a deep seated reason for these feelings. I for one am tired of seeing people judge others for their opinions and commenting on this fourm. All Bruce is doing is educating some of the lesser knowledgeable people on here. I for one...enjoy seeing his posts, learn from them, and even have changed my views on some of my operating techniques. For a person to become "tired " of seeing somethng must mean your spending to much time looking and being judgemental....I will leave the judging to a higher power, and enjoy what life has giving me... illegal or not... Of course now you're able to judge me as a person who (1) speaks his mind (2)reads and learns from things (3) Tells people what he thinks....As you have...But if I get tired of seeing something...I avoid it....just ask my first wife!...LOL... I in no way think that you opinion is not valid, just as my opinion is valid too...I am tired too...so I will close for now.....Have a nice day all...73s from Central Southern Ohio...and Bless all the Vets who have giving us the right to express our opinions in this Great land of ours...~OHIOBIKER~
Trans-America 5275.............PS...I also enjoyed your posts Antennadude on the facts of mobile beam antennas...and had concidered asking about some information from you regarding a set up for a mobile I have...and maybe if I haven't PO'd you buy stating my opinion I may still... |
Bullseye
| | Posted on Friday, April 05, 2002 - 11:12 pm: |
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Bruce NEVER said not to do it he simply stated the legality of the manuever. Why do certain people feel it needed to jump on Bruce almost everytime he posts something because I for one use and appreciate his "tech comments". The point here is to state your opinion,as Taz and myself have debated on several occassions, but that is the best part of this forum. You can "argue" a point and still have fun and usually the next day or two post to help out whoever you disagreed with in the first place. Just remember what you learned in grade school "If you can't say something nice don't say anything at all" |
Taz
| | Posted on Friday, April 05, 2002 - 11:29 pm: |
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No bruce, its just its not an INFORCED LAW |
Taz
| | Posted on Friday, April 05, 2002 - 11:55 pm: |
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Agreed bullseye,
couldnt have said it any better.
If you cant face the facts then why complain? |
Taz
| | Posted on Friday, April 05, 2002 - 11:58 pm: |
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Antennadude:
THATS WHY ITS AN "OPEN" FORUM
Taz |
409
| | Posted on Saturday, April 06, 2002 - 4:09 am: |
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Well bruce. i know the processor boards look good on the scope, but in the real world they don't really sound a lot better for the money you spend. I have had a lot of comparison experience with them and there's not really a big difference in sound quality over a power mic. But , like i said, it looks good on the scope and probably does cut down on splatter but to get real punch in AM modulation, you are going to need more extensive processing than most of these cheap little boards offer. |
Tech833
| | Posted on Saturday, April 06, 2002 - 11:59 am: |
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707: I'll be at the NAB all week myself. You have my email, let's hook up for lunch. Luch is my treat!
My wife and I, along with my assistant and his wife will be staying at the Mandalay Bay. |
bruce
| | Posted on Saturday, April 06, 2002 - 1:17 pm: |
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409 no doubt they are very limited in how much they will do for you i seen figures that 2-3 db of improvement is all you can expect with audio while RF clipping can result in as much a 9 db improvement. But the facts are if you are going to do anything they do help unlike changing your sinesoidal output to a square wave. I do a lot of lisening and hear some realy shabby signals one guy was 40 khz wide at about 6 db down so badly distorted i could hear him on fm better than am on my alinco dx-70 but he thought he sounded GREAT and BRAGED about how much AUDIO he had ... i would have loved to see what he looked like on a spectrum analizer like a christmas tree ill bet. |
707
| | Posted on Saturday, April 06, 2002 - 10:51 pm: |
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Hey Tech833-
check Gummers mail.
Catch ya at NAB. |
SSB2103
| | Posted on Monday, April 08, 2002 - 10:14 am: |
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Food for thought, Bruce sometime takes the fun out of the experiment huh. He tells you before you get to tearing your radio up what you need to know. If you desire to continue after being told, what the problem. I think Bruce is just trying to keep everything in spects. For those who forever trying to get more, maybe you should go ahead and spend the 4,000 dollars and buy the big dream radio. I bet you won!tlet the clowns that call themselves tech mess around with that radio.
Bruce I don!t always agree with your thoughts, but I do appreciate your effort to keep us informed. Thank you. |
bruce
| | Posted on Monday, April 08, 2002 - 10:08 pm: |
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SSB2103 WRONG im the bigest experimenter around but your right i like my radio to look good.... now if you want to sound / look like crap i dont have a problem with that either see i had a few bad radios too.... one ARC-3 that made most of the bad ones on cb sound good... AS for spects whoes spects??? thats up for debate as for accepted rules FCC or otherwise i dont write them ... sorry i had no input. Realy i dont care what anyone does but im not going to give you or anyone else known bad advice... like cutting out the limiter. There are accepted ways to increase audio without turning a good radio into a $39 peace of junk. As for myself when / if you hear me on the air all my radios comply with accepted rules wether or not you beleve in them. Finaly remember if you disagree with me your are welcome to question anything say i dont walk on water and im not always right.
bruce |
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