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Dead Key vs Big Swing

secret squirrel

Lustrous Potentate
Oct 5, 2008
662
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Washington, PA
I have researched this forum and other CB forums and this topic has peaked a curiosity question. I am not a radio technician and have only considered CB radio a hobby for the past 18 months.

My question is if I have two Cobra 29s with the same microphones, same antenna, coax setups with acceptable SWR. The first Cobra 29 is stock, but tuned and aligned properly DK 4 watts with a 3:1, 4:1 modulation. The second Cobra 29 has been mod to DK 2 watts and swing to max output. Will one of the CBs siginal be able to talk over the other CBs siginal. Lets say the recieving station is at five miles from the transmiting CBs over flat land and atmospheric conditions are idea. I was listening to some local Tri-axle drivers today that sounded like the guys were yelling at each other over the CB, then I realized it was how their radios were tuned. A third guy broke in from the same location and he sounded like he was as clear as being next door. This question developed from listening to those drivers. I am not asking who builds the best Cobra 29, just which one may talk stronger given identical circumstances and why.

All opinions welcome.

Thank you,
 

Oh boy, is that a question or not! Only sure way of finding out is by asking the ones doing the yelling/whispering, sort of, if you can believe them, sort of.
I think you'll find that doing things right usually beats doing things in some secret, mysteriously 'better' way. If you can't do something it's usually because it either can't be done at that particular moment, or something just ain't right. If you have close to 100% modulation, it just don't get no better than that. Plus or minus a little bit won't usually hurt, but it also isn't usually noticeable either. The key words there are "a little bit", which might be something like 10% maybe. After that, you are fooling yourself is you think it helps. (Sort of like those gas mileage figures on new car windows ...Yeah, right, advertising.)
Can you improve any radio from absolute stock? A little bit, but don't expect miracles. If there really was such a 'miracle' tune, don't you think that the manufacturers would be doing it? Uh... I've got this great bridge for sale...
- 'Doc
 
there are choices in this hobby .
go with a big high performance (and attention drawing) antenna or a smaller/stealthier leser performing antenna ? (yes i know the wilson 1000/5000 are high performance and not very attention grabbing)
cb or export radio ?
echo or no echo ?
talk back or no talkback ?
amp or no amp ?
going for a 4 to 1 modulation deadkey ratio shooting for %100 modulation , or , swinging like a monkey and sounding like charlie browns teacher ?

i agree with W5LZ and try to do things the right way .
 
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The output transistor can only produce so much power.

You can lower the carrier and increase the modulation level and, at close range, this would over power a stock (100% AM modulated) radio at the receiving station.

However, you can still do better with the stock setup by peaking to max output and still retain 100% modulation. This setup will talk farther, and it may even be able to over power a molested (2 swinging 20+) tweak job. Why? because the final transistor can only produce so much output power and trying to lower the deadkey to get more modulation also produces higher harmonics, which robs your signal of power.

The best station will have the classic 100% modulation AND a big fat dead key. I love it when you can key silence on the band.
 
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Thank you for your response. One of my personal experiences in this matter came from the travels of my Uniden 66XL. I bought the Uniden 66Xl from E-bay. SC2708 final. It sounded fine to me, but the needle on the watt meter would DK, but not move when I spoke into the mic. The first local tech, I took in to said the radio had never been tuned, and was poorly modulating. He said never to mess with the final. His tune job consisted of melting the wax from the tuning slug and removing it. He charged me 3.00 and said thats all it needs. I didn't like the sound so a second local guy put in the cap mod, which he called the standard swing kit- cap and diode. He said it DK around 2 watts and would swing to 32 watts. Locals said it sounded OK, but would not always hear me. Third tech was a big radio shop I found on the net. I sent it away with a 2 pill box to be tuned to drive the box. The big shop detuned it to 4 swinging to 9 to drive the amp. The local come backs was that 4 swinging to 9 sounded the same as the previous tune of 2 swinging to 32. The final tune of this radio in wich I am keeping and can hear the differance and recieves good responses from locals. The swing kit was removed, MOSFET conversion done and proper tune and alignment. I have a 160.00 Uniden 66XL that I use as my primary AM base. Lessons learned and from past posts I concluded that I got away on the cheap side.
 
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I have a 160.00 Uniden 66XL that I use as my primary AM base.


I have at least $250 in my Cobra 29...between the echo, tune up, retunes, alignments, swing kits, etc...I found a reputable shop, a member on this board, and have stuck with him.

Doing it right the first time is a whole lot cheaper!
 
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ive got less than $150 in my sparkified uniden 78LTW and 2018 xtreme mic .
 
ehhh, been a while since I had it done....I'm thinking I remember him stating it does around 1.25 and swings to around 18 to 20 on a scope?

It was set up to drive a 2-pill at a 1:4 deadkey/swing ratio.
 
He fixed all the damage others had done before him...he unclipped it, I believe realigned it, and made it sound 100% better than it did. Everything else had been done prior to him getting hold of it...talkback, 1969 final, echo, etc.

I'm surprised that radio had enough parts left to fix...I literally had one "tech" hand me a bunch of "unnecessary" parts from that radio...enough to cover the bottom of a coffee cup.

After owning an unclipped radio, I would never clip another one. I get nothing but flowers for any of the radios DTB set up...I need to make time to get that Grant down to him...

One thing I'll add is that although this particular radio showed more "power" on my RatShack meter before he redid it, it actually hits a known receiving station near me with a point higher S-unit now...
 
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That was DTB ? Wow !! IM guessing that was the way "you" wanted it Steved ? Please don't get me wrong here. IM assuming (and you know what that can cause from time to time ) I've just heard you mention his name a few times in a few threads here and there.

I say Wow ! because he has always seemed to be a stickler when it comes to right and wrong ways for tuning radios over the years. Although , money is money and I certainly wouldn't hold it against him if he did what "you" wanted.

You see Steved , I like DTB's know how to a degree on how and why things work for the better , been reading his stuff now for getting on 6 years or so. So maybe I need to understand more ? although I do understand 4 to 1 ratio is concerned towards given radio , but not as far as a amplifier from given radio ?

Do you see where IM coming from here ? DTB and a few others like him have always talked about clean signals in would pretty much mean clean signals out. It's not always rocket science but if you were running a 29 into ,lets a Texas Star 250 , chances are, it would look like a 2 watt DK ballpark into the amp.

So mathamatically speaking (scope for say) your 29 at 100% modulation (remembering that there is really no such thing as anything over that in a scoped out world) your radio should do around 8 watts pep , there's your 4 to 1 ratio from radio . Alrighty then.

What you think that Texas star 250 with 2 x 2290s in it , that are basically 80 watt devices going to do now ? OK , what is 2 x 80 ? = 160 .......the question would be , with a clean scoped out signal into your box what you think you might get realistically ? 160 watt clean peped out signal would be nice huh ? and that would be from a 60 to 70 watt DK .

Keeping in mind steved , these are clean in and clean out numbers , no waste for the most part , all utilized watts as they were meant to be. Who would know better then DTB himself on this matter. So now we take your 29 and take it to 1977 disco teched !! Hmmm , Now it's doing 1.5 watts and swinging for the fences !! I bet that audio is 200 some odd percent now in the audio department !! but remember ,there's no such thing as anything over 100% modulation . So what would the rest be steved ?

now we hook that 250 up and we see the numbers game , looks like about 65 to 250 swinging now. So when the radio was a cleaned signal in and was giving a good clean 160 watts pep out at 100% modulation , what would the extra 110 watts pep be ? I think you no the answer to that already ?

Like I said , if DTB did this work on your 29 , IM impressed and puzzled at the same time ? Hmmmm For the simple fact that I have read 100s of threads on the good the bad and the ugly of all of this and always DTB or Freecell putting in there very good knowledge of all of this at any given time.

As I said , I certainly wouldn't hold it against him if he did. I don't have a problem with swing kits or anything else along those lines. But I always "thought" they did ? (and very understandablely why) This is why I have never ever been a fan of anybodies Blacklists towards others, so to speak .

These techs are surely right about one thing , there is truly a right way and a wrong way for doing things , but does it come down to those mighty green backs in the long and short of it ? I've known some pretty good techs in my time and I've known a few that "would not" go against there own grains of know how for any money. (I honestly knew a couple like that , one has retired and one has passed on about 5 years ago)

I've also known a few that always knew the differents between right and wrong as well as the others , but , they would also do what the customer wanted , the wrong way principles never effected there cash boxes and i don't think it would merit them on anybodies blacklist either. I've been out here for many years now steved , and these guys have taught me a thing or two about radios and amplifiers , IM no guru , IM but a hobbiest. I pay attention around these parts. (or at least I try)

I hope you don't think I was trying to give you a hard time here Steved ? I wasn't . I guess there are just things I remember that others in this business have stated in black and white for all to read. I honestly do not have a problem with a 4 to 1 ratio from anybodies amp , nor do I care about a radio that does 2 watts and swings 50 , these kinds of things have never been by crosses to bare. What would matter the most to me , would be that a guy like you was happy with what he had as far as a radio and amplifier was concerned.

I've never been much on Einstiens theroys to a degree with this shit , but learning for the better has always been a plus for me. I can only hope I don't speak with forked tongue ? and walk the talk the best that I can. I truly have a passion for this hobby steved and for what works the best and what may not , because what may not ? will always work as well , just not as clean and pure as the other. IM no saint.

I've rather enjoyed watching many of you learn as I have over the years ....to a degree anyway , I'd be lucky if I've even scratched the surface of know how with this shit ? It's been very interesting watching the right way crowds and the wrong way crowds on how they run there equipment , I think all those false numbers are pretty cool for what they are , false.

I often think that learning the truth and why things work the right ways have kind of put a damper on my hobby over the years. it's kind of like the drunk that gets a nudge form the judge and ends up in Alcoholics Anonomous only to find out he had a problem and only for it to ruin his drinking for the rest of his life.

I like Dave to a degree Steved , I think he knows his craft fairly well. It's sounds to me that you have enjoyed his work and the outcomes there after. And that is what should mean the most in the end. A Happy Customer. Peace
 

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