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rci2970n2 bias help

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  #9  
Old 06-04-2011, 03:02 PM
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Your Meter has to be put in series with the points being tested, not parallel.
what model of meter are you using?
On mine you must move the leads into a different set of inputs DC+A and DC-A to measure current.


73
Jeff
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Old 06-04-2011, 04:42 PM
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Hi AudioShockwav. I have a radio shack cat.no.22-810 meter hope that helps. I have dca Dose not have the - sign other then that. I have settings for diode, ohm, dcv, acv, Would any of these setting work to test the driver and final bias settings? And i guess the most in portent part is were do i put the test leads? I can not find ept-695015a pcb in any other radio. I really appreciate the help Thank you guys.

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  #11  
Old 06-05-2011, 09:13 AM
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If your meter will not work you can set the bias by voltage, 3-3.4 volts to the irf-520's finals and drivers. I would try to set them all as close as possible since the voltage method is not the most accurate way.


I wouldn't recommend and voltages over 3.4 volts or under 3 volts.

And make sure your in side band mode!

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Old 06-05-2011, 11:33 AM
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Thank you for your input joedirt. After a lot of reading on different post about the mosfets. That is the only way i could see to set them with the meter i have. So last night i set the driver to 3.4 volts. The factory had it at 3.63 volts. I read that the lower the irf520's are set the cooler they run. But at the same time you get less wattage from them. So i am going to set the finals and will let you know were the factory has them set at. Thanks again.

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Old 06-05-2011, 03:08 PM
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Quote:
Originally Posted by cbkidd1 View Post
Thank you for your input joedirt. After a lot of reading on different post about the mosfets. That is the only way i could see to set them with the meter i have. So last night i set the driver to 3.4 volts. The factory had it at 3.63 volts. I read that the lower the irf520's are set the cooler they run. But at the same time you get less wattage from them. So i am going to set the finals and will let you know were the factory has them set at. Thanks again.
id much perfer a cooler running radio and lose a few watts that noone will notice anyway
sorry i dont have any info or help for ya. but am curious how it was
setup from were ever ya got it vs the way your gonna set it up
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Old 06-05-2011, 03:45 PM
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When i bought the radio it was putting out over 300 watts. Before i started talking on it i wanted to make sure it was set up right. So i researched the irf520 mosfets. And found that a lot of people had bought the same radio and because the power and voltage was not set right the mosfets burned up. Good thing i took the time and did some research on both the new rci2970n2 and the irf520 mosfet first. Now i hope someone can tell me the right setting for voltage so i can put the radio back together.

Last edited by cbkidd1; 06-05-2011 at 06:04 PM.

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Old 06-05-2011, 03:53 PM
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Quote:
Originally Posted by cbkidd1 View Post
When i bought the radio it was putting out over 300 watts. Before i started talking on it i wanted to make sure it was set up right. So i researched the irf520 mosfets. And found that a lot of people had bought the same radio and because the power and voltage was not set right the mosfets burned up. Good thing i did so mine would not be one of them. If you are going to make a quality radio like a 2970n2 then you sure make sure it is going to work right before you sell them. Looks like from what i have read a lot of people found out the hard way.
If the factory didn't set up the radios correctly before they shipped them out; then they would be deluged with returns and warranty repairs. The ONLY place that I know of - personally - that RUINS radios is RadioActive Radios. First hand knowledge - BTW. Have these radios been getting a bad rep because of being poorly adjusted from the factory? I never heard that yet.

So long as the driver and final are set up correctly; it should be fine. Is the final - the one before the final power amp - a MOSFET too? If so; then MOSFET's are voltage controlled. In which case, you would want to have the voltage set at a point where it has just enough to turn/switch it on. Then, I would adjust the hi power VR to a desirable level. Preferably to 75% of its potential output - IMO. . .
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Old 06-05-2011, 04:35 PM
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Quote:
If the factory didn't set up the radios correctly before they shipped them out; then they would be deluged with returns and warranty repairs.
It is my understanding that when this model first came out, this is what was happening, guys were seeing huge numbers out of the radios, they were drawing excessive amperage and running hot as a firecracker.....and a lot of them dropped like fly`s.
I think that problem was addressed by Ranger and it got solved.
If Larry ( DX Man ) see`s this I think when he got one of the new ones he was seeing large current draw, and If I remember right, Dave (DTB Radio) helped him sort it out.
Maybe he will jump in here and correct me if I am wrong.

73
Jeff
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