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Vanillagorilla
Intermediate Member
Username: Vanillagorilla
Post Number: 309
Registered: 4-2005
| | Posted on Sunday, November 13, 2005 - 8:28 am: | 
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If I had an amp with 4xMFR492 (rated90w each @ 4w input) I should assume NO MORE than 4 watts in from transmitter and preferably more like 2-3..correct?
Just trying to understand whether this is or IS NOT a high drive unit...seems to work better/ sound better driving it harder...like 6-8 in but I won't till I know better.
I'm guessing a 90wDK swinging to 350 is "supposed" to be better than 175wDK swinging 375.
Thanks~ |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 1880
Registered: 7-2004
| | Posted on Sunday, November 13, 2005 - 6:24 pm: |
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older mrf492's were rated at 70 watts PEP out with 5.6 watts in. new ones are 90 watts out with 4 watts in.
90 key/350 swing will prolong transistors lives. if it's lived through 175 key, it will continue to live. for how long though, is the question. if it gets HOT at 175 key, back it down to 150 key, or 125 key. add a fan, if you haven't already. using the 1:4 ratio theory & 90 watt transistors, you can see if 4 watts from the radio gets you 90/350, then it is most likely NOT high drive. 'high drive' is most likely a BIG resistor on the input side somewhere. even then, high drive was considered the early 10 watt radios. NOT todays 40-50-90-150 watters.
run it where it sounds best  |
Vanillagorilla
Intermediate Member
Username: Vanillagorilla
Post Number: 315
Registered: 4-2005
| | Posted on Monday, November 14, 2005 - 2:29 pm: |
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Roger that..was never told "sounds overdriven" yet and I DO have critics out there!
Seems SWR stays lower when drive is above 3w and even better at 6 (like 1:4 tops). Nearly flat at 7. Whichever....a longer (MUCH!) patch cord between radio and kicker helped alot. Probably along the same lines as useing a low pass filter I suppose. Strange thing is that SWRs are always fine UNLESS Jeep is running...ign on and truck running they will sit at 2:1 until you speak into mic then drop to normal range and stay...that is until you key again...no bother at this point. I need to take a break from over analizing and talk!
Thanks~Hank |
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