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Dead Key vs Big Swing

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Rf Engineer
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Join Date: Apr 2005
Location: non-cartesian cyberspace
Posts: 1,250
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mack you're babbling again.

by S.K.705 on Thu Oct 30, 2008 8:44 pm
Must have been a forehead scratcher Booty ? 2 weeks and no answer to your question. Is this for you ? Dude , You really can't go wrong with a Francis at 4 ft . I personally swear by these antennas' over the years for there performance.

IM truly no Master Chief when it comes to these , but 4ft of anything isn't a whole lot . I say Francis antenna's because they have proved themselves over the years. I've heard many guys use the 4 footers with some power on the side and they always sound pretty darn good.

WHICH IS IT?

by S.K.705 on Sun Nov 02, 2008 3:20 pm
Barjan owns a whole lot nowadays. Why does that make them bad guys ? Whatever the case maybe ? Unless I was a trucker and with a company that was very strick. I wouldn't run a 4ft anything on my vehical of choice. Bottom line for me ......Not Good Enough ! After 20 some years in this hobby , if I can't at least run a Wilson 1000/5000 or something at least in a 5.5 ft range ? I don't think my conscience could live with it.
 
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There are a lot of assumptions being made in this thread. I'm sure that at least a few of them are not correct. Also am not going to try to correct them, it's been done too many times with no seeming affect. So, as with any generalization there can certainly be exceptions. In general, any more than 100% modulation is a waste of time. A 'gimmick' is something that's used -instead- of doing it right, and always has some characteristics that just are not expected or wanted. Is that 'old fashion' thinking? Yep, sure is. But, it's also still true.
If you just have to 'push' till it gets ridiculous, make whatever it is work till it can't work anymore, then fine, have at it, have fun. Don't expect a huge increase in desirable output. And don't expect it to 'live' forever. Neither is very realistic, not to mention the pain you'll feel in your wallet. Sort of like wanting to do the 1/4 mile in 3 seconds with a '64 Volkswagen. Dang sure would be nice, but don't hold your breath. You know?
- 'Doc
 
I agree with what your saying here Doc. I've listen to and read the truth so many times around here from those that seem to know there crafts very well. I personally don't care what somebody else wants done to there equipment , and no matter what it is ? if the customer is happy , I suppose that would be all that mattered to me.

Nobody has to defend to me what's right or wrong , I've already been there and done that over the years to basically no avail but at the same time I surely got to learn something along the way. I wonder how many in the business would go against there own grains of knowledge for the mighty green backs ?

I surely could never hold it against them if they did for the simple fact they opened it in the first place (and it's what the customer wanted). But it also seems to me that maybe more so is done off the scales then on the scales concerning cb radios and amplifiers over the years. (IM sure a few other types of radios as well)

Figuratively speaking (on the scales so to speak) there is no such thing as anything over 100% modulation period. This much I do understand to the degree that it has been carved in my brain for life.

This reminds me of somebody I once worked for back in the early 90s , J&S CB's and Guns in San Gabriel , So.Cal , very good tech and amp man. Although I didn't have the understandings of today , he tuned radios according to scale (so to speak)

Well there was another tech across town that would really piss him off ! his radios were tuned and as loud as hell !! off the scale (so to speak) I honestly didn't understand why Joe was so pissed off at this guy ? This guy had a fairy good following of a customer base. Although IM sure ole Joe tried to explain it to me back then , but it more then likely didn't compute to me at the time.

I know now what he meant about clipped diodes and swing kits and what not. Weather they were clean or dirty , they still worked and he had a very happy customer base back then. (Joe has since retired and ole Amos the Indian has passed on) I conceder both of them friends of mine once upon a time ago.

I think about what some who know there crafts well have said over the years trying to explain why this works and that doesn't work and why. Although the mighty green backs may win through the Einstein theorys of what is right , I personally wouldn't hold it against them. This is why I've I've always cringed when it would come to blacklists made up by anybody, for the simple fact that what goes around will come around , especially if one is not true to there schools and beliefs.

I've said it many times over the years that it might be best for those to humble themselves rather then open a pit of shit only for them to later be swallowed by it. One used to say that your everyday CB'er doesn't want to handle the truth Doc (I was one of them and still go against the grain more so then not when it comes to a dollar)

How many of them really care to know the truth anyway ? I don't think it really matters much to them and it shouldn't have too.It just gives those that know the different's something to chew on and debate when ever they feel fit. So be it ! That might just mean another lesson learned to somebody that might care.

Radio operators that only operate and don't care to understand other then if they sound good and there amps are putting out and the needles are swinging, I think those are right where they should be. Happy with what they have not knowing the truth as it may be concerning them and there equipment. It's all good.
 
I read statements like any more than 100% modulation is a waste of time, or there is no such thing as more than 100%.
On the negative side, thats true. Hitting 100% on the negative side causes splatter and distortion. However, there is nothing wrong with going above 100% on the positive AM if your amplifiers are capable of the wattage.

Why would they make a modulation meter that reads up to 150% on the + side, but only to 100% on the - ??
Meter is here: Radio Engineering Associates
 
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First, there is such a thing as more than 100% modulation. Second, more than 100% of 'negative' modulation results in no signal, no output. It really helps if you know what's being measured and why. Doing that measurement with a sine wave of constant 'tone' will show what's happening. Voice modulation being made up of a huge number of 'tones' is very, very difficult to analyze in the same way since the voice modulation isn't close to being symmetrical. It isn't easy or cheap to do that sort of measuring so the average person/tech just isn't gonna have the equipment.
Won't get into who to ask, too many reasons not to.
- 'Doc
 
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Now I do not have a scope to see modulation levels and i do have a radio that has had the limiter clipped. Some may agrre and some may not just something i thought worth mentioning, especially if you are running any type of an amp. I have a 148GTL, when using a 1 pill or 2 pill amplifier and using a bird meter in the average mode, playing with the mic gain, I found out something very interesting. If I wasn't putting out a big hammer and allowing some forward swing on the bird and I adjusted mic gain on radio I noticed that on my radio, about the 10 O clock position was perfect. I could get the greatest forward motion on the Bird. If say i went past that i may get forward swing, but not as much. I contribute this to "overmodulation" and clipping the audio. While keeping it set lower I believe this gives more headroom for the Audio/RF circuit. Anyone else come up with results like this?
 
I will take a radio that produces the same power as the swing radio in carrier watts and knock it off the air.

This may be true, but I never run barefoot. I use radio strictly as an exciter. Low DK and lots of swing for me. If i want power, i just flip on the driver and if that doesn't work. I turn on the main box. I use these boxes to get carrier. If radio gets turned up to hi, it ends up shutting down audio because the radio is not capable for hi DK and still swing forward. Generally speaking. Ever hear some of those guys on the superbowl and they have a big hammer out there, but they sound real tight.
 
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This may be true, but I never run barefoot. I use radio strictly as an exciter. Low DK and lots of swing for me. If i want power, i just flip on the driver and if that doesn't work. I turn on the main box. I use these boxes to get carrier. If radio gets turned up to hi, it ends up shutting down audio because the radio is not capable for hi DK and still swing forward. Generally speaking. Ever hear some of those guys on the superbowl and they have a big hammer out there, but they sound real tight.
I will take a radio/amp combo that keys 500 watts with no forward modulation and bury your rig that is only producing 500 watts pep no matter what your low carrier scenario is..
 
I will take a radio/amp combo that keys 500 watts with no forward modulation and bury your rig that is only producing 500 watts pep no matter what your low carrier scenario is..


LOL I just use a Bird. If I am gonna fight/ shootout with someone, The DK is gonna be so that when I am talking, the bird is just gonna twitch forward and backwards just a little bit.
 
:whistle:For DX the dead key can be increased at the expense of modulation for the sake of getting there. After all 100% modulation does no good if you can't get there to begin with.....

The big international shortwave broadcasters used to routinely run 250Kw or even 500Kw but at about 85-90% modulation. The would run the modulator tubes for a certain time then swap them out to the RF amplifier section and install new tubes inthe modulation stage. This was for economic reasons BIG tubes are expensive. They wanted the sheer power of the carrier to overcome fading and interference while realizing that 85-90% modulation was more than adequate to reach their audience. Tubes operate much harder in class B audio service than in class C RF service.
 

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