| Author |
Message |
    
Bigbob
| | Posted on Sunday, January 18, 2004 - 10:15 pm: | 
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Are there any amps out there that use a matched-8 set of sd1446,possibly with a sd1446 driver,say a palomar or a boomer or the like,could you drive something like that to good effect with a dx2517 if it has no driver transistor?Bigbob |
Sparkomatic
| | Posted on Monday, January 19, 2004 - 10:06 am: |
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Sounds like a Messenger 4V. |
Rover
| | Posted on Monday, January 19, 2004 - 12:02 pm: |
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Hey!
I got of one of them (M4V) |
Wildbill
| | Posted on Tuesday, January 20, 2004 - 11:47 am: |
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Try and find some MRF-455's, I know that eight of them will smoke in an amplifier, I know that 1446's is suppose to be equal, but I think the 455's are better than the 1446's. Here another thought 8-MRF3800's or 8-MRF421's or 8-MRF492's, all better than the 2879's in my opinion, if you can find them. Wildbill |
Tech671
| | Posted on Saturday, January 24, 2004 - 4:14 pm: |
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The Texas Star DX1200 driven by your 2517 and a KL60 or 203 would do well. |
Sparkomatic
| | Posted on Saturday, January 24, 2004 - 7:16 pm: |
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MRF455-60 watt
1447-70 watt
MRF3800-100 watt
MRF492-90 watt
MRF421-80 watt
2SC2879-120 watt...the only one of these that can be volted. The best of the best! |
ryan
| | Posted on Sunday, January 25, 2004 - 11:22 pm: |
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MRF454-80 watt (if you can find em) |
Wildbill
| | Posted on Monday, January 26, 2004 - 10:38 am: |
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You're right the 2879's can be volted, but look at the spec. sheet on the Motorolas versus the Toshiba's, look at the gain factor for these transistors also. Wildbill |
Bigbob
| | Posted on Monday, January 26, 2004 - 7:19 pm: |
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I've read where motorola is pulling out of the hf transistor manufactory,so toshiba may be where it's at,and one other thing when the 1446 is tested at 50mhz it takes 7 watts in to produce 70 watts out,at 30 mhz it takes 5 watts in to produce 90 watts out,this is according to RF Parts and if you look in their on line catalog it is listed as a 90 watt transistor for HF,my average with 4 of 'em is 460 watts how does that compute for peak watts,maybe about 690 naw can't be.Bigbob....P.S.got my phone back on. |
Bigbob
| | Posted on Wednesday, January 28, 2004 - 8:28 pm: |
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I had an amp with mrf455a tr's,a pair,talked on AM so long the studs desoldered from the pills,POOF,they were very high gain,3 in 60 out,and high-beta to boot,the real problem;steel washers between pills and heat sink,huh?Cost me double the price of mrf455s to repair.Bigbob |
Adshar64
| | Posted on Saturday, January 31, 2004 - 11:24 pm: |
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What are you going to "volt" the 2879's at? |
Bigbob
| | Posted on Sunday, February 01, 2004 - 8:01 am: |
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How about a 800 watt amp 2 pills,50 volts dc,two irf154 892$ mp,need mega bucks and it's just plans and a schematic oh and tech8541 steered me to the site I lost that has combiners and splitters so you can run 4 ts667v amps off one radio,cool huh.Bigbob |
Wildbill
| | Posted on Monday, February 02, 2004 - 11:47 am: |
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I've seen 2879's volted as much as 21.5 volts, but I don't suggest you try that if you don't know anything about volting. Unless you have deep pocket $$$. Wildbill |
Adshar64
| | Posted on Wednesday, February 04, 2004 - 5:14 am: |
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2SC2879's wont handle over 18v. At 21.5v they are smoke. Get a new voltmeter  |
Wildbill
| | Posted on Wednesday, February 04, 2004 - 9:00 am: |
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You are only going by what you've been told, until you do an actual test yourself, I will keep my volt meter. Wildbill |
Adshar64
| | Posted on Saturday, February 07, 2004 - 11:36 pm: |
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How do you know that? Ive replaced more sc2879's than I can remember, and have seen plenty blow on a car regulator fault (toyota)that jumped the voltage to 20.7v smoked em twice on this customer until the intermittent fault was permanent and the regulator replaced. This was in a TS50s which has two 2SC2879 finals. If your real show me a pic of your voltage hooked up to a SC2879 collector circuit with a ammeter in line. |
Wildbill
| | Posted on Sunday, February 08, 2004 - 10:31 am: |
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You're talking about 2879's in a transceiver application, I'm talking about 2879's strictly in an amplifier. I'm not going to debate you that this is true or not, but this is a common setup that some of the radio operators here in my town run. If you can't fathom that, sorry. Wildbill |
Butcher 318
| | Posted on Sunday, February 08, 2004 - 8:55 pm: |
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Wildbill, don't waste your time, everyone knows that your hard core Davemade and X-Force comp guys run them at 20-21 volts all the time. Yea they smoke afew but they do hold up when everything is dialed in. |
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