To swing or not to swing

[slprydk]

If you set your swingkit up for asymmetrical modulation

IF, the word speaks for itself... Do you use a scope, an RMS reading meter, or a Peak reading meter to accomplish this one?

If you set your swingkit up for asymmetrical modulation your carrier increases with your mod, so your never going to really get over a 100% CLEAN MOD. You can always run more than a %100 but you negatives are going to be at zero volts creating distortion.

Yes, when the negatives hit zero distortion starts because you are at 100% modulation regardless of what the positive peaks are doing. Think of it this way, when your negatives hit bottom and stay there for any length of time it is the same thing as your positive peaks flat topping, it is distortion in either case because, positive or negative peak, you have reached the electrical limit of your amplifier. This means your positive peaks can swing to high heaven but if the negatives hit zero you are at or over 100%. You can see this in just about any 29LTD with a swing kit and the diode clipped, well if you look at it on a scope that is…

on a scope when your looking at a radio with a swingkit the carrier increases with the modulation so your scope lies to you too.

The negatives still tell the tale regardless of what the positive peaks are doing.

Your talking about a swing kit, and for the most part this means a resistor and a capacitor in parallel, there's no magic here. These two parts installed as a swing kit do nothing to prevent your radio from going over 100% modulation. If your radio can sound distorted and go over 100% without the swing kit, its going to do the same thing or worse with the swing kit.

 

[BOOTY MONSTER]

Yes - SSB...
Not an issue with anybody that I talk to regardless if they are ten miles away or several thousand.
Never has been either.
It's just a rehash of the same old jive.

robb you should know enough to know that ssb is all swing and am has a carrier and that they work in two different ways . using a ssb transmission as evidence of huge swing ratios being good on am is .... well ......... just wrong to put it nicely . it makes as much sense as suggest that since having a carrier works well on am that its perfectly fine for ssb also .
apples and oranges.

yall have to keep in mind joe dirt is a believer in motor mouth maul and his mauldulator scam/thing . i think its all BS , but thats just me . i think thats where the "asymmetrical modulation" stuff is comming from .

 

[Highlander_821]

"using a ssb transmission as evidence of huge swing ratios being good on am is .... well ......... just wrong to put it nicely . "

.

Well, to put a finer point on it, it is a "non-sequitor". (And also wrong).

And the "everybody in New Zealand loves it" thingie is an "appeal to ignorance/authority". Also wrong.

 

[Robb]

robb you should know enough to know that ssb is all swing and am has a carrier and that they work in two different ways . using a ssb transmission as evidence of huge swing ratios being good on am is .... well ......... just wrong to put it nicely . it makes as much sense as suggest that since having a carrier works well on am that its perfectly fine for ssb also .
apples and oranges.

yall have to keep in mind joe dirt is a believer in motor mouth maul and his mauldulator scam/thing . i think its all BS , but thats just me . i think thats where the "asymmetrical modulation" stuff is comming from .

Yes BM, I have been aware of it - thnx.
But I will continue to disagree that AM sounds bad with this 1 watt/swing way. I doesn't. It depends where I set my mic gain. When properly adjusted, it sounds xlnt. There is always going to be some distortion in just about every setup! Some may be more noticeable than others.

If the motor mouth maul guys like what they are doing; that is fine with me. I'm not going to tell them if it sounds bad or whatever. This hobby has its diversities. I don't want to tell 821 that he sounds like crap compared to others coming out of IL that I hear during skip. Oh; I just did - LOL! If he likes what he likes then that is fine with me.

 

[Highlander_821]

Also, bring that 1 watt swinging 30 junk to my neck of the woods and my 10 watts swinging 30 will mask you out. No one will even know you are there, because you will be under my carrier's boot for most of the time.

Guaranteed. :closedeyes:

 

[Shockwave]

The comment about the carrier moving with modulation making the scope an inaccurate way of determining modulation percentage......is wrong. Modulation is the movement of the carrier between the unmodulated base line and fully modulated peaks. The scope is the most accurate way of instantaneously measuring modulation and is why they build them as "Station Monitors".

The 1 watt swinging to 30 watts has some people saying it sounds good and others saying it sounds like crap. Who is right? The answer is probably both of you since it depends a lot on the receiver and signal strength being received. The weaker the signal, the less noticeable the distortion may be.

The real significant factor is the detector used in the AM receiver. Even if negative peak limiting were used on the transmitter, anything over 150% positive modulation peaks are likely to sound distorted in the typical diode AM detector. Beyond that point requires a syncronous detector. Commercial AM radio stations have figured out how to modulate at 125% positive peaks without adjacent channel interference.

Many noise blankers also introduce distortion when used on a signal that has an extreme modulation to carrier swing ratio. Even with the mic gain turned down, at 1 watt carrier and 30 watts PEP that's too much swing to sound good in most receivers. Futhermore, without negative peak limiting the adjacent channel interference from a transmitter set like that would be horrendous.

 

[bob85]

highlander is spot on,
the videogates posted above nicely demonstrate that glowing reports often mean little with regards how you actually sound.

 

[BOOTY MONSTER]

highlander , since he'll be bleeding into nearby channels and you wont , the folks that want to hear him can just go off of his intended tx frequency and hopefully make enough sense of the over modulated splatter to make out what hes saying .

 

[15minigrass]

highlander is spot on,
the videogates posted above nicely demonstrate that glowing reports often mean little with regards how you actually sound.

I didnʻt mention if I sounded great or not, thats not what Im after. What Im after is a low DK and a max swing w/o distortion. But could adding a power mic or an eq to tailor the Audio make it sound better(with the NPC/RC mod) or would it still sound crappy. To me, My audio sounded muffled due to the microphone I was using.

If thatʻs the case then the only way to achieve this is to install Top Gun boards. IDK, you guys are the proʻs @ this. So lets hear it.

Here to learn!! Aloha Jim....

 

[BOOTY MONSTER]

hey jim , the reason you sounded muffled is because of compression caused by over modulation . when the modulation/audio circuit is pushed beyond its ability to respond any higher it starts clipping , but distortion has already set im befor then . the pills and rf transistors arnt the only things in our radios that have limits on what ammount of output they can achieve . adding a power mic will just make things worse .

 

[ron103067]

It seems I started a war which was not what I wanted I wanted info cause I was going nuts trying to fix my audio I was using a texas ranger fd1 dk 2 watts swinging to 20. That went into my Killer bee 250 hdv. Now two trucks same make and model where 100 foot from each other going down the road another truck of same make and model was app. 5 miles away running basically parallel. I already stated my setup up other then I run a predator 10k 9 inch single coil the truck behind me was running a tuned connex 3300 no amp and a 3 foot fiberglass antenna Now I should've been kicking his butt all around. But alas I wasn't he was being heard better than me. I had a decent carrier but hardly any modulation the other guy had a little less carrier but his modulation just ate me up. Now the funny part I removed d75 which on this radio gives me talk back, only thing was that I couldn't hear my self so I stopped today and had a tech remove swing kit and reset my radio dks 4 watts swings to 12 to 14 watts. Guess what I can now hear myself in the talkback so much as I'm going to have to get a pot to make it a variable. Now since this has happened got alot more good reports on my radio. I will not say wether a swing kit is good or bad. My opinion cause the one that was installed on my radio was crap (I got the radio with it installed) they are crap, thats my opinion. If it works for you so be it. I just don't see how it can be a good thing. To me it seems like revving an engine when you get more power from just standing on it. But once again I'm no tech just wanted to see where people stood on this.

 

[15minigrass]

hey jim , the reason you sounded muffled is because of compression caused by over modulation . when the modulation/audio circuit is pushed beyond its ability to respond any higher it starts clipping , but distortion has already set im befor then . the pills and rf transistors arnt the only things in our radios that have limits on what ammount of output they can achieve . adding a power mic will just make things worse .

Thanx BM. Im waiting for my Jackson to arrive and maybe send my Grant up to my tech to achieve the low DK and full swing. I know a good peak & tune and align will do the job properly. I just need a low DK for my AMP.

My amp was tuned to take a low DK so it wont overheat. So thats what Im worried about, killing the Amp.

Anyways, thanx for the info. Aloha, Jim.....

 

[15minigrass]

hey jim , the reason you sounded muffled is because of compression caused by over modulation . when the modulation/audio circuit is pushed beyond its ability to respond any higher it starts clipping , but distortion has already set im befor then . the pills and rf transistors arnt the only things in our radios that have limits on what ammount of output they can achieve . adding a power mic will just make things worse .

Thanx BM. Im waiting for my Jackson to arrive and maybe send my Grant up to my tech to achieve the low DK and full swing. I know a good peak & tune and align will do the job properly. I just need a low DK for my AMP.

My amp was tuned to take a low DK so it wont overheat. So thats what Im worried about, killing the Amp.

Anyways, thanx for the info. Aloha, Jim.....

 

[BOOTY MONSTER]

you didnt start a war , LOL .

so you took out the swing kit and have about a 3 to 1 ratio of swing to carrier and got a lot more good reports on your radio .

cool beans


sounds like a plan jim . is the black widow 350 basically a texas star 350 ?
always good to see you on the forums

 

[bob85]

hello jim,
my comments were not aimed at anything you said nor did i mean to offend you, it was what the guy gating you said and imho he should not have said, he did not even tune his receiver to your frequency before recording you on ssb,

increasing am swing over what you have at the moment is unlikely to make it sound better,
there are far too many people with big swing into crappy sounding class c amplifiers on am and people using class c on ssb telling each other how great they sound, that in no way makes it true,
a topgun distorter is not the way forwards, its audio jim but not as we know it,

good to hear you are getting a jackson, i just picked up an early blackfront jacko myself for the car.