Copper Talk » Open Forum » Archived Messages » 2002 » 09/01/2002 to 09/30/2002 » Pills in palomar 400 « Previous Next »

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snowman
Posted on Sunday, September 08, 2002 - 1:44 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

this paloamr 400 has four pills in it ,any one know what they are rated at,it is swing to 365 on high.
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Bigbob
Posted on Monday, September 09, 2002 - 8:39 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Probably sd1446s mine swings to 404 watts consistently with 36 peak watts ssb and it don't hardly get warm at all.
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snowman
Posted on Monday, September 09, 2002 - 10:17 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

they are sd1446 pills ,and my dose not get warm
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Bigbob
Posted on Tuesday, September 10, 2002 - 10:00 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

I "hear" they are rated at 70 watts each.
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2600
Posted on Wednesday, September 11, 2002 - 1:33 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

The SGS-Thompson data sheet has a graph showing power output plotted to drive power in (for one transistor). It tops out at 100 watts for 7 watts (peak) drive. Sounds like a normal 30-watt peak export radio will deliver about all this amp can absorb, giving you about 400 watts out. Like any mass-produced product, some will do 10% or so less than the average, some will show 10% or so more. Besides, very few RF wattmeters are any closer than 10% when used on an antenna. One guy who sees 360 watts, and another who sees 440 watts might well BOTH be getting the same 400 ACTUAL watts from the amplifer. A difference of 10% power either up or down, is less than the width of the receiver meter needle on the other end. They'll never be able to tell.

73
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bruce
Posted on Wednesday, September 11, 2002 - 7:22 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

2600 my HB amp class C on FM runs right at 300 out on 29,6 your right on with your numbers. Now if it was AB2 on SSB i could see it pushing 400 watts i wonder how close there data sheet is on 6 meters next project ? HUMMMM
bruce
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Bigbob
Posted on Wednesday, September 11, 2002 - 8:52 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

I said sd1446s were rated at 90 watts in rfparts and a couple of techs had other data sheets saying they were 70 watts and again I said,to clarify matters,90 watts at 30mHz,70 watts at 50mHz.Then one tech posted long,so I figured if I can't beat'em,join'em,obviously my catalog is out of date.So I try to go with the flow with my last post and I'm still indirectly told I'm WRONG,cest la vi.
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2600
Posted on Wednesday, September 11, 2002 - 11:45 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

The data sheet says this is a 50MHz transistor to start with. At 50 MHz, it will multiply the drive power by 8 to 10 times at full drive. At 27 MHz, the power GAIN is about twice that, times 16 or so. They meant this one to function just fine at 6 meter frequencies. Remember that a power output claim of 70 watts includes an "engineering margin". Out of a thousand of these parts, the weakest one will meet this claim. The rest will usually do more, by 15% to 30%. They meant it for FM radios, not AM or SSB. Their rating is for an unmodulated dead key (that's all the amp sees when you transmit FM) of 70 watts. The peak-to-average ratio of AM modes, (including SSB) allows you to get peaks higher than 70 watts, so long as you keep the average power low enough that it doesn't overheat.

73
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Bigbob
Posted on Thursday, September 12, 2002 - 6:34 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

I'm sorry 2600 sometimes I resemble another poster on here or he resembles me,six o one half dozen the other,again pardon me please.I keep havin to pry my foot out.