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D&A PHANTOM TRIPLE STAGE Question

512RI

Member
Aug 31, 2011
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I just picked up a clean D&A phantom triple stage amp. First of all I've read the tune up directions and cannot for the life of the amp get anymore than 200w from this thing. I've read on multiple sites that there is a grid tune on the back of the amp, well there is none..not even a spot for one. This is a tan/brown D&A, not sure if it's older/newer. I am driving it with my Cobra 2000 which i can dead key 2-4 watts and swings about 20w, yet the Phantom does not swing at all. Could it be bad tubes?
 

Those amps are cheaply made and not complicated. I'd say you have bad tubes. Let us know how much it's going to cost to retube that amp once you verify the tubes are bad. $$$$$$$
 
I just picked up a clean D&A phantom triple stage amp. First of all I've read the tune up directions and cannot for the life of the amp get anymore than 200w from this thing. I've read on multiple sites that there is a grid tune on the back of the amp, well there is none..not even a spot for one. This is a tan/brown D&A, not sure if it's older/newer. I am driving it with my Cobra 2000 which i can dead key 2-4 watts and swings about 20w, yet the Phantom does not swing at all. Could it be bad tubes?

All of the 3 stage Phantoms I've seen had the grid adjust you described on the rear panel, along with an on-off switch. The grid tune was used on 10 & 15 meters, but not on 20 & 40. I understand some Phantoms were made for 11 meters only. Does yours have a bandswitch or not? Also, can you post a picture ?

- 399
 
It does have a band switch on the front panel, but nothing on the rear..only the receive-amp switch.
 
Have you looked internally for a pot to adjust the grid?

If this is a 10-12 tube model useing 6lq6 tubes you have two choices.

1) Sell it on ebay to someone that will take the time to rebuild it and that has a surplus of good sweep tubes on hand. The 6LQ6 tubes run $49-$89 each new from actual tube shops and even on ebay from sources that test used tubes and sell as NOS want too much.

2) Gut it and use it to build a 2-4 tube amp useing Russian Ceramic tubes. If I had a chasis that had enough current and voltage to power 10-12 sweep tubes I would do the the following. I would order 2 GS31 Russian tubes and two spares. I would use a voltage doubler board and run 2xGS31 tubes and would have a nice 4000watt PEP grounded grid amp with 2000watt's of nice clean power to play with.

3) If you need it to have a driver circuit then keep that part in tact and use it to drive the Russian tubes. 2 6Lq6 tubes should drive the two Russian tubes just fine.

You will have enough space left over to add all kinds of circuits latter on. So you could at a later date and time revamp the tuning circuit, add a swamping circuit if you need one, add different control and protection boards ext.....as time goes by. If you want to use other tubes you could since you have enough transformenr power and current for 10-12 sweep tubes you could easily build a 2x3-500Z, 2-3x813, 2x833 etc........Test all the parts you remove and reuse anything you can. That is what I would do.I would never pay what they want for sweep tubes to redo an amp that large. That amp origanaly should have made 900-1200 watt's with 3.5 watt's in. In the 1980's you couldhave gotten a 12 matched tubes for that thing for $6 per tube cheaper if you did not need them all matched.
 
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Ok I found this guy on ebay and since this site has ebay auction links at the bottom of the page I am guessing it is o to post a link. If not I meant you harm.
D & A PHANTOM 500 6LQ6/6JE6 (10) Premium Tube Set | eBay

It will cost you $399.99 to get 10 6LQ6 tubes from him in a 10 tube kit any other tubes that are in their would also be in the kit. So I would not go that route at all.

If you want to donate it to a worthy cause I will gladly take it and use it to build a new amp that will look the same externally but be really different under the skin!
 
I have taken the cover off and there is def no pot to control the grid tune. There are coils though. I have done tons of research and read that some of the D&A phantoms were tuned for 11m right from the factory, this my be the case. I am by no means electronically educated enough to build an amp using different tubes, although 2000watts is tempting!
 
I have a ten tuber I just got and am trying to fix, I have no output yet, so your 200 is better than my none, lol
 
I have a two tube 6lq6 that is going to get new life breathed into her. She does not know it but she is going to be getting a 350-450 Watt RMS Russian ceramic tube installed! I refuse to pay top dollar for 6LQ6 tubes when I can buy Russian tubes with 3-4 times the output for 1/2 the price!She will become a 6m rig instead of a 11m oh I mean 10m rig.....LOL I making a funny about those stickers on back of them claiming to be 6m/10m amps for use by licensed Amateurs.....LOL Those sticker always make me chuckle when I see them

I have enough 6LQ6 tubes though to keep one of them going for about 25+ years so the better designs gets to live out it's life unmolested baring a better input tuning circuit to make it more broad band. The poorly designed one get's to have surgery. Hears in head " We can rebuild him, make him better then before, we have the technology!" Bionic Man noise sounds in back ground!!! Lee Majors face pops into mind......LOL

Nothing wrong with sweep tubes other then current cost to replace them. When you look at their unit cost int he 1980's of about $6 per tube you where looking at $72 for 1200-2000 watts of output pretty cheap when you look at bang for the buck! Fast forward to today and even at close to $400 it is not horrible considering what a single Emiac tube in the 1000-2000 watt output range would cost if bought new from authorized dealer. When looking at 200-400 watts though the bang for the buck is not that great considering the Russian tubes in that output range can be had for about $27 per tube shipped to your home if you are a savvy shopper and they are ceramic to metal and are actually rated conservatively for 350-450 watts of output from a single tube.

Do not waste you time looking for a deal on the alternatives to the 6LQ6 tubes because all of them even the 24,28 and 31 Volt heater models are just as expensive I looked over and over again! If anything you would be better off switching to 811A tubes installing a new socket's and doing what must be done to get them to work. Prices ont he 811A's and 813's are much better when you look at output power per dollar spent and the fact that they will be around for a long time from China.
 
D&A phantom single stage

I have been reading alot about the D&A Phantom triple stage!!
I have and older model phantom single stage, i just can't figure out
how to tune it out the right way. because it don't understand the grid control in the back of the phantom, When key phantom with 12 tubes I get alot of back swings.. I need help the right way peak tune the D&A phantom single stage with 12 tubes
 
Why you guys buy these 40 year old sweep tube amps is beyond my comprehension. To retube one will set you back more than buying a modern amp with modern tubes that will last 100 times as long as an old sweep tube, will run more power longer and transmit a clean signal. What's the lure here peeps?:unsure:

I had one in the 70's when sweep tubes were dirt cheap but when I see a 10 or 12 tube D&A on eBay and the seller is "unable to test" but there are 25 bids and the price it at $500.00...I just don't get it.

And let's not forget someone runing a 40 year old 12 tuber at lethal voltages that doesn't understand how to tune it or what the grid control does. That's just dangerous. Don't put yer lips on it!!!
 
I can't se paying all that money either. But, I have a 10 tube that I got for nothing pretty much. I could toss 10 el509's it and run it for 100 bucks. done deal.

I have 6 good 6lq6's, too bad I can't run the amp with 4 missing, lol.
 
Why you guys buy these 40 year old sweep tube amps is beyond my comprehension.

Well... for some of us it's about creating a certain station aesthetic. If the rest of your station is vintage CB gear, having a modern amp or even a vintage ham amp just throws the whole look out of whack. Yes I know- the receiving party can't see the gear.

Maybe I'm a bit goofy but the sensation experienced when I am surrounded in a cloud of HV and RF is something that no drug or intoxicant can equal. And when it comes to leaky amps it's hard to beat a sweep tuber!

I also get a thrill out of having a bunch of 40 year old gear, all of it made in the USA and still working after all these years.

Having said all that you are correct. The damn things cost a fortune to retube and won't last as long as a real amp. But it's a hobby, right? Whoever said that hobby expenditures have to make sense?
 
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Those ol Phantoms was a sweet amp...
I ran one of the Gray color ones and it was the 3 stage amp, with 10 tubes in it..ran this amp for about 8 years, I replaced the tubes once and the relays...
They were a very good amp...havent seen one in years these days...

I dont run a tube amp now a days, but Ive heard alot of guys on other forums say the tube amps are the way to go.....
I run the electronic amps now a days...
 
u figure it out ??

I just picked up a clean D&A phantom triple stage amp. First of all I've read the tune up directions and cannot for the life of the amp get anymore than 200w from this thing. I've read on multiple sites that there is a grid tune on the back of the amp, well there is none..not even a spot for one. This is a tan/brown D&A, not sure if it's older/newer. I am driving it with my Cobra 2000 which i can dead key 2-4 watts and swings about 20w, yet the Phantom does not swing at all. Could it be bad tubes?

well u have to tune it with everything turned on the high setting then everything else will fall into to place mid and low will be set ... im still figuring out the one i picked up and working on ... it has a issue but before it got running after 30 yrs of not being used and moved around fixed parts that had come loose in the poor shipping from place to place tuning it up 10 tubes silver gray .. it hit a 1000 watts then arched under side messing up a relay and coil ... so have to fix that that and try again ... tubes tested out at 90% all ... the keyer tube was bad also had to replace that picked up a new one from a friend that had a brand new one laying in back room new in box i was first to use that .... but i havent got to try side band power on it yet but it was dead keying a 1000 watts when the 42 yr old parts said nope im not doing it ... so im going to replace all the caps in it and change out a few resisters that are out of spec and going to replace them with glass ones that are 1% and a bit bigger in wattage to handle stuff better ... im not giving up on it yet ... but poeple already wanting the tubes out of it ...lol but it will run again hope to see it run another 42 yrs ...:w00t:
 

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