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Tracker293
Junior Member
Username: Tracker293
Post Number: 15
Registered: 9-2007
| | Posted on Saturday, March 26, 2011 - 3:03 pm: | 
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How much dead key is ideal for the sweet 16? I will be driving it with a RCI 2970N2.
Thanks |
Moonraker
Intermediate Member
Username: Moonraker
Post Number: 273
Registered: 3-2005
| | Posted on Saturday, March 26, 2011 - 6:29 pm: |
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Probably 15-20 watts from the radio. You want the amp to key about 1/4 of the max pep. If it does 1200 watts set the DK at 300. I wouldn't set it up to DK more than 300 though. It won't take a beating as well as a comp amp. |
Big_mic
New member
Username: Big_mic
Post Number: 1
Registered: 2-2011
| | Posted on Sunday, March 27, 2011 - 2:32 pm: |
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http://www.cbtricks.com/Amp/txstar/dx1600x/graphics/dx1600x_class_comparison.pdf
Ummm.... NO.... you dont want your dead key into the amp that high.... Look at the ratings/inputs/outputs |
Big_mic
New member
Username: Big_mic
Post Number: 2
Registered: 2-2011
| | Posted on Sunday, March 27, 2011 - 4:58 pm: |
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6-7 watts I would think would be sufficient.... But go with a final reading of your watt meter... run mine at 200 watts of carrier modulating it with some headroom popping to a 1,000 watts.... 2879's are 100 watt devices and i run them as such... With a Watt meter you can see more sure, but use a spectrum analyzer and see where that energy is really going. If I could never use it on the frequency/channel I was on it wasn't doing me any good, and the extra heat to the amplifier wasn't doing it any good either... |
Moonraker
Intermediate Member
Username: Moonraker
Post Number: 274
Registered: 3-2005
| | Posted on Sunday, March 27, 2011 - 6:33 pm: |
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I was just speaking from my personal experience and what my meter said. A 300 watt dead key from the amp is 100% safe if his antenna is properly setup and tuned. Even if 15-20 watts is too much it isn't going to instantly blow the amp. Key up only long enough to get a reading and adjust accordingly. |
Charliebrown
Intermediate Member
Username: Charliebrown
Post Number: 169
Registered: 10-2002
| | Posted on Monday, April 04, 2011 - 10:41 am: |
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3 WATT DEAD KEY SWING TO 200 ON THE RADIO. THE AMP WILL THEN BE AT ABOUT 200 DEAD KEY AND SWING FULLY. |
Sitm
Intermediate Member
Username: Sitm
Post Number: 418
Registered: 1-2004
| | Posted on Tuesday, April 05, 2011 - 10:02 am: |
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I am getting alittle confused here, is this the Texas Star that has a max drive of 100 pep? |
Charliebrown
Intermediate Member
Username: Charliebrown
Post Number: 171
Registered: 10-2002
| | Posted on Tuesday, April 05, 2011 - 12:57 pm: |
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YES IT IS. IF YOU HAVE TWO LARGE FAN'S RUNNING AND KEEP IT COOL AND YOU ARE NOT LONG WINDED AND YOU KEEP THE DEAD KEY TO 2 TO 3 WATT'S AND LET IT SWING IT DOES FINE. THE MODULATION IS STILL VERY CLEAR AND CLEAN. IT DOES FINE RAN LIKE THIS. OF COURSE AS WITH ANYTHING IT COULD SHORTEN THE LIFE OF THE TRANSISTOR'S BUT NOT MUCH. I LIKE THE TEXAS STAR PRODUCT'S. |
Big_mic
New member
Username: Big_mic
Post Number: 3
Registered: 2-2011
| | Posted on Thursday, April 14, 2011 - 7:24 pm: |
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Unfortunetly if you use a Spectrum analyzer you will see much beyond 1200 watts PEP is wasted energy.. So not only is the Amp being abused but the energy isn't being used on the Freq/channel your operating. the 2879 is a 100 watt device and much beyond that is just splattering the spectrum...
Remember to gain 1 S unit or about 6 DB, you have to take a 1,000 watts and go to 4,000 watts for just 1 S unit...
I run mine at a 5 watt dead key and go about 45 watts PEP for a 1,000 out and looks great on the Scope and Spectrum Analyzer...
Either way enjoy ... The hobby is a lot of fun! |
Charliebrown
Intermediate Member
Username: Charliebrown
Post Number: 179
Registered: 10-2002
| | Posted on Friday, April 15, 2011 - 7:21 am: |
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Big Mic, Have you taken a look at how most competition amp's are ran and what they are getting out of the 2879? Yes I know that they do not last as long and it does cause more problem's with other freq's but, with a very low swr and fan's to keep it very cool AND MOST OF ALL LOW DEAD KEY AND LET IT SWING. I hardly ever use my amp. but, when used it is just warm to the touch. I had a friend a good distance away and he turned down the rf gain to see if there were any difference from swinging from 100 max to 200 max and he said it did make a difference on his radio meter. The modulation stayed clear and no over modulation problem. No argument here Mic, just a different point of view and the way we use what we have. Nice to talk to you Mic. Have a great day and a better tomorrow. |
Sitm
Intermediate Member
Username: Sitm
Post Number: 427
Registered: 1-2004
| | Posted on Friday, April 15, 2011 - 10:06 am: |
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Great information Big mic, |
Charliebrown
Intermediate Member
Username: Charliebrown
Post Number: 180
Registered: 10-2002
| | Posted on Friday, April 15, 2011 - 1:28 pm: |
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WHAT ABOUT THE COMPETITION AMP'S THAT RUN ON 13 TO 15 VOLT'S,TWO 2879, 200 WATT DRIVE AND GET 500 WATT'S OUT? I AM SURE THESE ARE NASTY AMP'S ON THE OTHER FREQ'S. SO HOW DO THEY GET A 2879 TO TAKE THAT KIND OF DRIVE AND GET SOO MUCH OUT? |
Big_mic
New member
Username: Big_mic
Post Number: 4
Registered: 2-2011
| | Posted on Thursday, May 19, 2011 - 4:41 pm: |
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I'm kind of getting around too late on the posts here... But great too meet both you Charliebrown and TY Sitm, Yes I have looked at the competition amps, and yes with some volting and gross over modulation you can get them there...
Take that same Amp, as another example, measure power through a good watt meter, than take a good low pass filter and put it on the back of the amp, and modulate and run it the same way, I think you will definitely notice some difference reading that same meter after the low pass filter, after it has filtered out all the nasty harmonics and garbage, a watt meter see's watts, ALL WATTS, whether it's dirty or not...
As you said going from 100 to 200 watts you won't see much unless your seeing it on an accurate meter, Doubling your power is 3Db or 1/2 S unit... Won't or doesn't mean much in the scheme of things.. Unless your going for lip cutting, at the wire competition audio that will win you the competition, but if that 100 watts is over driven to 200 watts of splatter, harmonics, etc... than how much of that 1/2 S Unit is going to register on that frequency your talking on? You'll see it on a watt meter, but never see it at the other end, overall nastier modulation in the end is about all....
It's all in what you want and what you look for... I've never done competition, so I can only give my opinion from my side of the fence, but if you are going to run an Amp that way, than Texas Star is not the answer... But if you want a great, clean sounding Amp on SSB and AM and run it proper without over saturation, which is easy to do with these low drive amps, and don't mind using a few extra Amps to do it, than the Texas Star might well be for you. 
5 Watts= 200 watts 30 watts= 850 Watts and 42-45 watts= 1,000 watts ... Alot of variables but that is approximate... So I run 5 in and modulate the Amp to 800 for 100% Modulation and when i get a little boisterous on the Mic the Amp will Pop a 1,000 ...
On SSB with 100 in you will see 1400+ out... |
Sitm
Intermediate Member
Username: Sitm
Post Number: 432
Registered: 1-2004
| | Posted on Friday, May 20, 2011 - 2:19 pm: |
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Big M, what kind of amp usage are you seeing with these outputs
5 watts = 200 = amps used
30 watts = 850 = amps used
45 watts = 1000 = amps used.
Thanks for your information |
Big_mic
New member
Username: Big_mic
Post Number: 5
Registered: 2-2011
| | Posted on Sunday, May 29, 2011 - 12:17 am: |
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I am seeing:
200 Watts= 48 amps
850 Watts= 95 Amps
1,000 Watts= 115 Amps
They are current devices and running them cleaner means more Amps... But feeding them a healthy diet they do not disapoint... I absolutely love mine, and am not sorry that i chose one over the Copper Board Models (X Force, Dave Made, Etc... )
I barely with a good amount of talking with 200 watts carrier, peaking 800 watts with hard peaks to a 1,000 ever get the fan Kit to kick on, I think in 2 weeks I have seen it kick on 4 times ...
It's a hearty unit, and despite the bashing it receives, they hold their value and are very hearty units, If i have to buy another Mobile Amp it will be this one hands down. |
Onelasttime
Junior Member
Username: Onelasttime
Post Number: 32
Registered: 8-2011
| | Posted on Friday, August 19, 2011 - 7:01 pm: |
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You know most guys with a Sweet 16 use a 50watt Class C modulator amp to drive it. That assumes they are Ancient Mariner and talk on AM almost totally.
I owned a sweet 16 before going to a 3200 and I used an add on RF amp onto the back of my RCI 2950. The DX 100 Kit came with an MRF455.Depending on the beta rating of the MRF 455 you got it would be around 80-100 watts on side band and about 65 on AM.On side band I always ran full power and never had a problem. On AM I normally ran with just my radio's power output with the DX100 kit on it. On the rare occasional some one would be a jerk and I actually turned up the power I can run from lowest power to full output of 65 watt's and never over drove my amp. Normaly though on AM I would set my RF out put to 12 O'Clock and let my audio swing.
Keep in mind though that I was working at a shop that did mostly warranty repair for Ranger,Standard,Kenwood,Icom etc......So before that amp even landed in my trunk I set it up so that with my power turned all the way up I did not start tossing harmonics all over the place.... The shop I worked for warrantied amps and we would put tamper proof paint on the case and such. So it was routine to upgrade those parts known to fail in the Texas Star line before we sold the amp and it and the owner's radio where matched n our shop. We never sold an amp to a customer and let them just walk out with an amp under their arm.
With out a scope and annuated test tones I would take the Peak projected power based on the transistor data and calculate a power setting. SInce linear amps of this fashion are not 100% efficient I would ignore the RMS rule of what .707 and go for .600 X peak projected output and that will almost guarantee beyond a doubt that you will not have a splatter box or be pushing it too hard.
Never run a radio with a cliped ALC modified a tad ok clipped never!!! With amps any garbage in your signal will get amplified as well and you will sound dreadful even at low power levels and unintelligible at higher power levels. I speak Spanish,Russian,German,English, a litle bit of French and Korean(Army Brat) and their are times like on channel 6 that I cannot understand a single word coming out of their mouths even though I know it is English!! Oh and last year I learned American Sign Language good enough that the school asks me to work as a translator....My point is I am good with speaking languages and understanding spoken words so if I cannot understand someone it is bad!!! I can only read and right English,Russian and German though. So make sure your signal coming from that radio is nice and clean!!!! Everyone hates the guy with the splatter box |
