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6LQ6 Are 50 Watt Tubes Right?

Wire Weasel

Senior Moment
Dec 13, 2008
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I've seen where somebody is claiming 400 watts + out of an amp with (2) 6LQ6's

Isn't his meter broke or he's blowing a bunch of hot air up my QSL's ? :whistle:
 

2 X 6LQ6 = 200 Watts depending on the band your on. I have an older Ameritron sweeptube amplifier that uses 4 6LQ6 that only does 400 watts which is what the owners manual said it would do but again this is also give or take depending on the band your operating on.

10 meters would show 400 with 4 tubes so 2 X 6LQ6 will show half of that leaving an amazing 200 watts :LOL:
 
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Here are the specs of the KW Atlanta transceiver using 2 6LQ6's -

SSB: 500 W (PEP)
CW: 350 W
AM: 125 W

The above are "INPUT" so you figure about 1/2 for output.

The Dentron GLA-1000B will put out about 600w SSB PEP with 4 6LQ6's
 
I have a Nitro 300A that uses one 6LQ6 to drive four 6LQ6's. It is showing a maximum 700 Bird Watts PEP into a dummy load. You have to hit the right "Ahhhhhh" note to get it there.
 
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In the RCA Receiving Tube manual it's rated for 30 watts dissipation continuous, 200 watts temporary overload ▲not to exceed 40 seconds.
 
D&A labeled their 6MJ6 tubes "D-50", or something like that.

As a practical thing, you can dissipate 50 Watts on the anode of this tube for a half minute, more or less before it starts to show color and warn you that you're exceeding the "red line". Seems to take about that long for it to cool back down.

The bigger picture is a simpler matter of tradeoffs.

More power equals shorter service life.

Less power equals longer service life.

People ask how hard they can push an amplifier on the wattmeter. I answer that they're asking the wrong question. What you're really asking is how soon do you want it to go "POOF!"? A day, a week, or a couple of years. The wattmeter should get calibrated by how long until the next kaboom.

But for anyone who just wants to burn rubber, I recommend making friends with the tire salesman.

73
 
I have measured my Nitro 300a amp with both Bird and Daiwa meters. It has One 6LQ6 driving Four. I get an even 800 watts PEAK with a 500 hz injected tone.
 
The bigger picture is a simpler matter of tradeoffs.

More power equals shorter service life.

Less power equals longer service life.

People ask how hard they can push an amplifier on the wattmeter. I answer that they're asking the wrong question. What you're really asking is how soon do you want it to go "POOF!"? A day, a week, or a couple of years. The wattmeter should get calibrated by how long until the next kaboom.

But for anyone who just wants to burn rubber, I recommend making friends with the tire salesman.
I have to essentially repeat this passage like a bible verse everytime an amp leaves my hands to a new home.
I've had to have this discussion about gs-35bs, and 3-500zs lately. A kw out of a 3-500z and she will likely run for the life of the owner in amateur service. But in cb world everyone expects 1500 plus from a 3-500. Sure, it will do it, but for how long? Is the 500 extra watts worth $269 for a new tube?
Wizard shows a 5000w single gs-35b on you tube. I've built some of them and I consider them a 2500w tube. At 2500w they will pretty much never break. At 3-3.5kw...its hit and miss. At 5kw?? I can't imagine how long it will last. Maybe forever, maybe a week, maybe 10 keys.

I think people are also component spoiled, as in they remember American made tubes, Japanese transistors and american capacitors as being able to sustain far more abuse than the datasheet would suggest. While this still somewhat applies to our favorite "Steel tubes", it's a much less forgiving lesson with everything else.

Me, I'd rather loaf my hemi along on the street and do an occasional trophy launch at the strip.
Some folks want to daily drive their turbo,nitroused, 500 HP Honda Civic shifting at 9k to goto the grocery store. To each his own.
Wtf do I know.
 
I have to essentially repeat this passage like a bible verse everytime an amp leaves my hands to a new home.
I've had to have this discussion about gs-35bs, and 3-500zs lately. A kw out of a 3-500z and she will likely run for the life of the owner in amateur service. But in cb world everyone expects 1500 plus from a 3-500. Sure, it will do it, but for how long? Is the 500 extra watts worth $269 for a new tube?
Wizard shows a 5000w single gs-35b on you tube. I've built some of them and I consider them a 2500w tube. At 2500w they will pretty much never break. At 3-3.5kw...its hit and miss. At 5kw?? I can't imagine how long it will last. Maybe forever, maybe a week, maybe 10 keys.

I think people are also component spoiled, as in they remember American made tubes, Japanese transistors and american capacitors as being able to sustain far more abuse than the datasheet would suggest. While this still somewhat applies to our favorite "Steel tubes", it's a much less forgiving lesson with everything else.

Me, I'd rather loaf my hemi along on the street and do an occasional trophy launch at the strip.
Some folks want to daily drive their turbo,nitroused, 500 HP Honda Civic shifting at 9k to goto the grocery store. To each his own.
Wtf do I know.
Old post. 6LQ6 are 30 watts plate CCS and 50 watts plate ICAS rating. The tubes with the added plate dissipators on each side add 5 watts.
 

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