| Author |
Message |
    
Hotrod
| | Posted on Monday, August 19, 2002 - 10:25 am: | 
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I HAVE A SUPERSTAR 3900 I BOUGHT FROM COPPER LAST YEAR.I DONE THE SUPER SWING MOD.WITH LIFTING RIGHT LEG OF R238 AND PUTTING A DIODE IN JUNCTION WITH IT AND I SET MY DEAD KEY 1.5 WATTS AND MAN IT REALLY SWINGS BUT PEOPLE SAY IT WASN'T LOUD,SO I SET MY DEAD KEY TO 4.5 WATTS AND IT STILLS SWINGS THE SAME WATTS IT DID AT 1.5 BUT EVERYONE SAYS IT IS SUPER LOUD NOW AMD MY MIC GAIN SETS AT 12 O'CLOCK.AND I SEEM TO GET OUT FURTHER WITH IT SET AT 4.5 WATTS,ANY REASON WHY THIS IS?? EVRYONE I TALK TO ASKS ME WHAT I'M TALKING ON AND BRAGS ON HOW CLEAR AND LOUD IT IS.THEY ALL THINK I HAVE A KICKER ON IT.THANKS ON ANY INFO. |
Ss8541
| | Posted on Monday, August 19, 2002 - 11:13 pm: |
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there is a 2 part answer to this. the 1st part is becuase you have increased your average power by going from a 1.5w to 4.5w carrier. yes you are hitting the same peak reading, but from a higher carrier. also your audio is distorting more from this higher carrier(most likey if it wasn't already maxed b4), so this false loudness adds to the equation. secondly, you are running more into something called gain compression. once the final/s hits a certain point, they are no longer truly linear. it takes more drive to make them go further. so at your low levels, the tx chain is pushed normally(up to the 15wpep level for a 3900- gain compression usually starts after this level) and after this the drive ratio changes. so with the 4.5w carrier the line of the gain compression is closer than from the 1.5w carrier. you can think of this like a speech processor. the speech processor compresses everything to a certain level set by adjustments of the processor. here the compression level is set by the max power of the final/s. the closer you get to the max power, the more compression you have, resulting in being louder. there is more to this, but i don't want to confuse you and others. hopefully i haven't already. |
307
| | Posted on Tuesday, August 20, 2002 - 12:37 pm: |
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In simple terms , take the super mod out..It will sound better..Good job Ss8541...
307 |
Hotrod
| | Posted on Tuesday, August 20, 2002 - 12:41 pm: |
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I THINK I UNDERSTAND WHAT YOU ARE SAYING Ss8541,BUT IS THE 4.5 WATT DEAD KEY ALRIGHT?? WILL IT HURT MY FINALS IF I KEEP IT THERE?? THANKS FOR RESPONDING TO MY QUESTION,HOTROD.. |
Ss8541
| | Posted on Tuesday, August 20, 2002 - 11:26 pm: |
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307 is right(about removing it) to some extent. if the mod is done correctly (your location is incorrect since ac is being beat against dc instead of another ac signal so audio clipping of the neg peaks occurs) it will be effective on the rxing end, and there will be no noticeable distortion. this mod is supposed to give positive carrier shift(broadcast term for npc) that the am broadcast companies have been using for yrs. 1 reason they use it is that it gives louder audio on the rxing end. but they, as it should be done here, use it in moderation(their systems are more advanced and wider in bandwidth).
so yes the npc when done correctly can have a positive effect. when done wrong a negative effect. to be done correctly, you need the proper test equipment, and a fairly good amount of knowledge in rf principles. even with the positive effect, there isn't a he!! of a lot difference from a 100% modulated radio. it just gives the swing that operators like to see. it also keeps the voltage reg cooler due to the lower amount of current across it.
you can leave it in, and leave the carrier at 4.5w without any harm, or you can take it out. with it in, there is no difference from having a 4.5w carrier and amc clipped or wideopen. many techs do this(clip or adjust amc past 100%) after preaching about 100% mod(and preach against npc/ppe). atleast that is what i gather after seeing customers talk about getting radios back that key 1w and swing to 40w. the techs are either using the mods(most likely incorrectly) or they are adjusting amc wideopen. if you have been around the forums for a while, you may remember a company that did this(they aren't the only ones, but the biggest ones) in the past.
by the way, it is supposed to be just ss8541, but the program here doesn't do lower case for your 1st letter. |
2600
| | Posted on Tuesday, August 20, 2002 - 11:23 pm: |
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4.5 Watt dead key won't hurt it.
73 |
Hotrod
| | Posted on Wednesday, August 21, 2002 - 11:27 am: |
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THAKS ALOT ON THE INFO GENTLEMEN.I GUESS I'LL LEAVE IT IN THERE FOR AWHILE AND SEE WHAT HAPPENS.I'M JUST USED TO HAVING IT SET THIS WAY AND EVERYONE SEEMS TO LIKE IT.THANKS AGAIN,HOTROD. |
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