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Message |
    
Audiophile73
Intermediate Member
Username: Audiophile73
Post Number: 129
Registered: 5-2004
| | Posted on Tuesday, October 31, 2006 - 4:52 pm: | 
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I have a RCI 2950dx. I am using a ts modulator, but I am looking to drive a texas star 500. Im thinking to get the best audio I would drive my 500 with my modulator. Then when I am talking SSB I will turn the modulator of being that its class C. I would keep it low, Key the 500 up at 100 or so and leave the rest for audio. Any opinions |
Hotwire
Senior Member
Username: Hotwire
Post Number: 1963
Registered: 1-2005
| | Posted on Wednesday, November 01, 2006 - 11:23 am: |
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My opinion for whatever its worth
Set the modulator to the side and just run the 2950 with the dx500.
On AM mode Set the 2950 to deadkey 2 watts and swing its max into the Texas Star. On SSB mode just drive the Texas Star full blast with the 2950 but remember that you might want to turn back the mic gain a little.
In fact the 2950 has to much power for the V mod and in reality the V Mod is twice the power the DX500 should be driven with. All that is going to happen is over modulation, distortion, splatter. The meter will say you have this mega watts but actually its gonna be reflected harmonics. Amps are gonna get real hot, transistors are gonna weaken and then one day one of those pills are gonna go poof.
I run a DX500v in the mobile with my 38 watt Connex 4800, Astatic 636. Just ask any Copper member who has heard it and they will tell ya, You don't need that modulator man. ......just my 2 cents worth, good luck
Kenny
CEF491 |
Audiophile73
Intermediate Member
Username: Audiophile73
Post Number: 130
Registered: 5-2004
| | Posted on Wednesday, November 01, 2006 - 12:45 pm: |
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Your connex is class c though. When I set my radio to 2 watts I wont swing any more than 4. Because a fully modulated am signal is twice the carrier. I think anyway. Oh well thanks for the advise |
Hotwire
Senior Member
Username: Hotwire
Post Number: 1972
Registered: 1-2005
| | Posted on Thursday, November 02, 2006 - 1:31 pm: |
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Audiophile73, My Connex 4800 is no different than your RCI 2950 as far as how the power transistors work inside. Those classifictions your talking about tell you how your amp was designed or built. The V Mod is class C because it is made to drive the DX 1200 and the DX 1600. Thats what all those little class C amps are for.I would imagine why a lot of the big watt customs are class C is because class C uses less power. AB-1 Amps use lots of power. Your DX500 is class AB-1. Ab-1 is the best for SSB and AM modes. I don't even worry about the amp classes, all my amps are ab-1 anyway. Check out this link, It is a really informative discussion about the topic from some of the most knowlegeable members here at Copper.
Kenny
CEF491
http://www.copperelectronics.com/cgi-bin/discus4/discus.cgi |
Im4jc
Intermediate Member
Username: Im4jc
Post Number: 201
Registered: 11-2005
| | Posted on Friday, November 03, 2006 - 12:37 am: |
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Audiophile, a fully modulated AM signal is 4 times the carrier, not twice. |
Hotwire
Senior Member
Username: Hotwire
Post Number: 1976
Registered: 1-2005
| | Posted on Friday, November 03, 2006 - 12:05 pm: |
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Sorry Audiophile, I posted a bad link. Gonna try to find it again. Like Im4jc states, 4 times the carrier is what you want.
bruce
Posted on Monday, September 01, 2003 - 9:23 am:
--------------------------------------------------------------------------------
Katt
To keep it simple ....here is a quick look at amps when i use power input im talking how much power the AMP used HOW MUCH POWER DOES THE AMP DRAW FRON THE SUPPLY INPUT TO AMP not drive power .... he goes ..
class " A" is on all the time low distorion but high power useage and low output only 30% for what ever power input ( if your amp pulles 100 watts from power supply you will get 30 watts out ) works great with all modes but uses too much power
class "AB" is bias near cutoff more output for a given input draw by the amp good for all modes less overal power used for same output( 40-50% ).
class " B " is bias at cutoff Here we get tuchy a class " B " amp will work well on all modes but harmonics and distorion are now becoming a problem
good output ( 40-60% ) for a given power input to the amp.
class " c " is bias past cutoff HIGH distorion but higher output at a give input as much as 70% output for a given input very good for FM / CW USELESS for am or SSB .... a REAL SPLATTER BOX if your nor carefull.
This was just ment to be a over view of the amps in the ARRL handbook you will find detailed infromation.
Bruce |
