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Having owned one (just like your's, with the first tube wired as a broadband driver, and the Z14 choke on the "drivers" toasted, so it was given to me), I can say this.

Expect an honest 600 watts out of it, reliably. Yes, you can get more, but those tubes are only rated at 33 watts of dissipation. That means you can get roughly 3 to 4 times that PEP out of it. Keep the carrier around 20 (up to 30) watts per tube. This is general guidelines for ANY sweep tube amp.

Yeah, you can get more than that out of it.

I also had a D & A Maverick I was given in 1990. It was a pre-73 amp. It still had the original tubes in it (marked D & A). The person that gave it to me ran his amp at 100 watts carrier and 425 to 450 pep output.

To each his own.

--TollHolio

Gonna drive it with an S9, eh?

Lordy, talk about ten pounds of copper in a five-pound sack.

In the old days, guys would use a Black Cat JB-12 to pump 30 or 40 Watts PEP into the four driver tubes on those. But it was like nitrous oxide on your daily driver. Goes faster, but watch how long you hold that button down. Blow a hole in a piston, and you're hitching a ride to work monday morning.

Your S9 is bigger than that, still. Has between twice and three times the drive power most early 70's base radios could pump going down a steep hill, shot out of a gun, and with a tailwind all three.

The more drive, the sooner you have let off of the key, pure and simple. That radio won't "pop" it the first or second key, the way a 150 or 200 Watt radio would. More like a deep-fry. So long as you pull it out of the fat before it's burned.

An attenuator to lose half or two-thirds of the radio's drive power is a possibility, but not posted on the web in convenient, ready-to-use form anywhere I know.

Radios keep getting bigger, year by year. That amplifier hasn't gotten any bigger in 30 or 35 years. It's meant to scream with a dinky Teaberry base with no more than 16 Watt peaks, and maybe 3.5 to 4.5 Watts average power.

An S9, huh? Nitrous, pure and simple.

73

__________________

These are not the 'droids you've been looking for.

I was thinking something along the lines of a new Cobra Mustang, or Subaru WRX STi.... They both come blown or turbo'ed stock... The aftermarket is now adding "chemical intercooling" with nitrous or methanol or even water!

Gains of hundreds of horsepower are had in the biggest systems..... It cools the intake charge, allowing more boost, the nitrous fizzles off in the chamber, giving an extra O2 atom.... Lots of good stuff.

But, as you said, too much of a good thing.

We didn't use JB-12s, we used Messenger AM30s, or Texas Star modulators (this is when they started, and use the 455 as a final in them).

Woooot.... And the one thing you forgot to mention is: When we where doing that to these 10 and 12 tube beasts, you could afford to go to Thrifty's every two weeks, hit up the tube tester and pick up two or three blown tubes... They only cost 3 or 4 dollars a piece!


--Toll_Free

The S9 thing was just a thought. I have never owned/used one of these tube amps, and figured, here is the place to ask!

I also have a very nice Cobra 2000 on the desk. How about that one with the D&A? I have a Kris Mach 3B, but don't know much about that one either, except that it works.

I also have a Siltronix 1011D that work real nice, but usually use it barefoot.

The 2000 will work great as an exciter for that amp.

--Toll_Free

Will I have to do anything special to the D&A to be able to use it on SSB?

I had someone on this site explain the "tune up", before use procedure, but was wondering if the amp is good to go on AM and SSB.

I guess I could just give it a go and see what happens.

If it has ssb delay, then you can use it, but keep in mind what Nomad said... It's all true, and the simple mod he posted would ensure your SSB enjoyment would go long time.

Engrish excepted


--Toll_Free

Wow, this thread's still going?

The Siltronix 1011 is likewise too big for the D&A box.

Found the pic and moved it to a new host. This is what the driver choke looks like after one set of driver tubes cherries up and blows.



Used to be the same color orange all over.

This one is strung between the inboard relay and the wire that leads upstairs to the driver tubes' plate caps.

Either using SSB on a linear with the 'stock' wiring on the driver sockets, OR using too much drive gets you this result.

Seen it over and over.

73

__________________

These are not the 'droids you've been looking for.

OK....I put it inline with the Cobra 2000. Radio dk is 3 watts, swinging to 15. On high I'm seeing 325 watts, and on low I'm seeing 150 watts.

The amp seems to work fine on SSB with good reports from locals that I talk to on a regular basis

Does this sound OK to those participating in this thread?

Um, much more than any wattmeter's reading, I would be concered that it passes the "Twin Peaks" test.

The final-stage Plate Tune, the right-hand knob of the top pair, has no physical end-of-travel. The Load control on the left will turn only 180 degrees, then CLANG!, it runs into an end-stop. The Tune control on the right has no such mechanicl end stop on it.

Likewise the lower-left Driver Tune knob is this way, too.

BOTH of these knobs should show TWO peaks on the meter in ONE FULL TURN of the knob.

Those two separate peaks may be on opposite sides, 180 apart, or they may be right next to one another.

What matters is that the upper-right Final Plate Tune. AND the lower-left Driver Tune should EACH show TWO peaks in one full turn of the knob.

It's late. I'm gonna skip explaining why this matters. But if you see only ONE peak in that full turn, it isn't really a peak. It's the control reaching the end of its travel, before reaching a peak. Looks like one on the meter, but it isn't, really.

If either knob flunks the Twin Peaks test, you'll next need to know at which extreme the knob that flunked came to rest.

A Tune control with only one peak will be at one of two positions.

1) Plates all the way apart. This is the control's minimum setting.

2) Plates meshed together as close as they will go. This is "Max" capacitance.

Gotta know which it is, to correct the outptut coil on that control.

Any time tubes are changed, there's the risk the Tune control for that set of tubes won't peak like it did with the OLD set of tubes. Running the tubes unintentionally out of tune causes the same stress on the tubes as if you did it on purpose. They last longer if both Plate Tune knobs are "peaked" to a real resonant peak.

73

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These are not the 'droids you've been looking for.