Author |
Message |
Cbblackbeard
Intermediate Member Username: Cbblackbeard
Post Number: 227 Registered: 12-2003
| Posted on Thursday, April 30, 2009 - 7:24 pm: |
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I have a linear which has 2 2290's in it. What should I set my radio's dead key at to drive it? How much amp draw does an amp like this consume? |
Bruce
Senior Member Username: Bruce
Post Number: 5028 Registered: 9-2003
| Posted on Friday, May 01, 2009 - 6:52 am: |
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A pair should require no more that 4 watts for full output. On 6 since 66
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Hotwire
Senior Member Username: Hotwire
Post Number: 2758 Registered: 1-2005
| Posted on Sunday, May 10, 2009 - 1:25 pm: |
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A standard cb such as a cobra 29 is a good match to an amp like that. Set the radio to dead key no more than 2 watts and swing no more than 20 watts and it will be fine. Kenny CEF491 Reading the mail around Indianapolis Indiana!
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Hotwire
Senior Member Username: Hotwire
Post Number: 2759 Registered: 1-2005
| Posted on Sunday, May 10, 2009 - 1:27 pm: |
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Will need around 20 amps to run...give or take for your setup. Kenny CEF491 Reading the mail around Indianapolis Indiana!
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Audiophile73
Intermediate Member Username: Audiophile73
Post Number: 151 Registered: 5-2004
| Posted on Wednesday, May 20, 2009 - 3:34 pm: |
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Without knowing the circuitry of the amplifier it is difficult to say how much drive you will need. If you don't have the tools to do this I would take it to someone that does. If the amp does in fact have two 2290 transistors, you will probably not see more than 160-200 watts out of this box. So to answer your question, your radio should have a carrier (dead key) of whatever it takes to get a 40-50 watt carrier out of your amp. Feel free to e-mail me with any questions you have. |
Ak3383
Member Username: Ak3383
Post Number: 50 Registered: 11-2005
| Posted on Saturday, June 06, 2009 - 3:34 pm: |
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With amps such as the one in question I agree that a stock input of 4-watts AM should work well. I have never had any problems running amps at those input levels. The dead key carrier might be a bit higher than if you run say 1-watt of input but I have had the best audio reports with a good strong carrier and some forward modulation. With the deadkey keeping the carrier higher all my modulation can be heard and not just the peaks of my voice. It keeps my voice/signal at a steady level and produces clean sound. |
Flying_cloud
Junior Member Username: Flying_cloud
Post Number: 35 Registered: 4-2009
| Posted on Sunday, June 07, 2009 - 3:36 pm: |
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The Amp Draw can be found out by this formula: V=I/R (Ohms law) Watts Divided by Volts= Amps If it is a mobile the standard is 13.8 Volts If a base in the U.S.A. the standard is 120 Volts nominal Flying High and Flying Proud!!!!!!!! CEF# 1028
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Ak3383
Member Username: Ak3383
Post Number: 54 Registered: 11-2005
| Posted on Tuesday, June 09, 2009 - 12:05 am: |
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The formula is right when applied to a normal circuit with 100% efficiency but the amp in question sounds like an AB class which is about 60% efficient. Meaning for example it takes 100 watts of power to make 60-watts of RF. |
Bruce
Senior Member Username: Bruce
Post Number: 5090 Registered: 9-2003
| Posted on Tuesday, June 09, 2009 - 2:07 am: |
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2SD1446 ... EFFICIENCY 55% SO you would need close to 200 watts about 18 amps for a 100 watt amp On 6 since 66
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Flying_cloud
Junior Member Username: Flying_cloud
Post Number: 39 Registered: 4-2009
| Posted on Tuesday, June 09, 2009 - 1:53 pm: |
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can you explain the AB class amp??? Flying High and Flying Proud!!!!!!!! CEF# 1028
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Tech808
Moderator Username: Tech808
Post Number: 16903 Registered: 8-2002
| Posted on Wednesday, June 10, 2009 - 2:07 am: |
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Class AB Amplifiers As the designation suggests, Class AB amplifiers are compromises between Class A and Class B operation. They are biased so plate- or collector-current flows less than 360 degrees, but more than 180 degrees, of each RF cycle. Any bias-point between those limits can be used, which provides a continuous selection-range extending from low-distortion, low-efficiency on one end to higher-distortion, higher-efficiency on the other. Class AB amplifiers are widely used in SSB linear amplifier applications where low-distortion and high power-efficiency tend to both be very important. Push-pull Class AB amplifiers are especially attractive in SSB linear amplifier applications, because the greater linearity resulting from having one amplifier or the other always conducting makes it possible to bias push-pull Class AB amplifiers closer to the Class B end of the AB scale where the power-efficiency is higher. Alternatively, push-pull Class AB amplifiers can be biased far enough toward the highly-linear Class A end of the scale to make broadband operation without resonant tank circuits possible in applications where broadband operation or freedom from tuning is more important than power-efficiency. Lon~Tech808 N9CEF~EN50mk CEF#0808~CVC#0002
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Mrclean
Intermediate Member Username: Mrclean
Post Number: 128 Registered: 12-2003
| Posted on Sunday, August 02, 2009 - 11:31 am: |
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What brand amp? |
Audiophile73
Intermediate Member Username: Audiophile73
Post Number: 155 Registered: 5-2004
| Posted on Saturday, August 22, 2009 - 12:24 am: |
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This is not a difficult question. Check out the datasheet for a Toshiba 2SC2290 transistor. There you will get a good idea for the output. Keep in mind these specs are for 12V, your car will be running closer to 14V, so you will squeeze a little more out. Two 2290 trans. ( I hate calling them pills ) will do about 160-180 watts. So set your carrier (dead key) to do about 80-90 that will leave you plenty of room for full modulation. Hope this helps. Please do this on a bench with a power supply and a appropriate dummy load. If you have any more questions feel free to contact me. |