D&A TRIPLE STAGE PHANTOM ISSUE

[BJ radionut]

RADIO FREE HOOTERVILLE!

 

[Sonar]

Nope Sonar many operators still use the old vintage stuff.

I have a Browning Eagle, then a Browning Eagle Mark III
Old colt tube type cb.

For amateur gear I have an old Swan 700CX, all tube with exceptions of a couple transistors.
Hybrids are Yaesu FT 102, Kenwood TS 820, Kenwood TS 830.

The amplifier I am using for Amateur bands has a tube that has not been in production in many years and is getting as hard to find as Hens teeth, 3-1000Z. ( I do have two new 4-1000's to drop in the socket if the old 3X1 goes South on me).

SO nope it is all about how YOU want to have your station, if you like vintage and want to maintain it then so be it, I think the old stuff is cool and real radios glow in the dark ( not neon led lights but tubers).

I'm happy to see so many people really enjoy the old tube gear. My tec is fairly sure the phantom has a weak tube. Considering the one's that are currently in there are original to the amp it might need a few. Mike of Mike's radio repair who does the work on my equipment is making it easy on me. I'm just going to send him the tubes and he's going to test them. I'll take it from there. 73

 

[Sonar]

Sounds like tubes SONAR,
IF it is indeed tubes talk to your tech about converting tubes

Four 811 a tubes will give you 500 to 600 clean output with about 85 watts of drive.

I purchased 10 6lq6's on ebay (tested and guaranteed).
I'm trying to find out if the Phantom is 1 driving 3 driving 6.
The low and medium shows esactly as it did almost two years ago (driving with 11/2 dk 20pep). From what I've read the output on low and medium is where it should be (lo 60 dk 230+ pep/med 120 dk 450+ pep).
It's output on the high side has dropped by about half (dk 140+ pep 600 then drops to 500 after 20 minutes). It used to show 250+ dk and 1000+ pep
Should I just replace the bank of 6 tubes?
If the Phantom is 1 driving driving 6 I'm assuming that the bank of 6 (six) 6lq6's is where the high power comes from but beyond tunning it then keying the mic I'm clueless . I unfortunately don't own a tubes tester but do have a friend who does. Unfortunately have to ship them for testing. Thanks 73

 

[wavrider]

I think you posted a pic of the inside of that old D&A somewhere before,
I recall seeing something that lookd like a 6jg6a tube,,then 3 6lq6,,then 6 6lq6, so the 6jg6a may be a first stage driver tube and is probably your weak tube maybe, let me se if I can find a schematic of that amp, D&A towards the end of their era was building amps out of whatever thay had left laying around so there is a few Frankensteins out there.

http://www.cbtricks.com/Amp/d_and_a/phantom_triple_stage/index.htm

schizo only shows 4 tubes drving 6 tubes so you have a one off custom I think

 

[Sonar]

I think you posted a pic of the inside of that old D&A somewhere before,
I recall seeing something that lookd like a 6jg6a tube,,then 3 6lq6,,then 6 6lq6, so the 6jg6a may be a first stage driver tube and is probably your weak tube maybe, let me se if I can find a schematic of that amp, D&A towards the end of their era was building amps out of whatever thay had left laying around so there is a few Frankensteins out there.

http://www.cbtricks.com/Amp/d_and_a/phantom_triple_stage/index.htm

schizo only shows 4 tubes drving 6 tubes so you have a one off custom I think

I was thinking what a bummer it would be if all I needed was a single 6jg6a. If the 10 6lq6's I purchased are as described I'll keep them.
I might purchase a single 6jg6a. I'm going to install 9 of the 10 6lq6's i bought and send the original d&a sylvania's to my friend for testing. The 6lq6's I bought will be here on Monday and if their as good as their description @ what I got them for I'd be happy . I'll let you know how everything works out . I appreciate all the help I get from y'all. thank you . 73

 

[wavrider]

if you can post another pic of the amp, tube side and then the bottom side, hopefully the pic will be clear enough to see how the tube sockets are wired up in the amp.

 

[ExitThirteen]

The Phantom that Sonar has pictured is the triple stage model. 1 - 6JG6A into 3 - 6JE6C/6LQ6 into 6 - 6MJ6/6LQ6. The 6MJ6 is the industrial/military spec grade 6LQ6.

Usually, the 6JG6A is the first tube to get weak, especially if the tube consistently sees more than about 2.5W deadkey on AM, and 15W PEP on SSB. The tube has a max plate dissipation of 17W, so it's very easy to overdrive and potentially "cook" the tube.

You can substitute a 6KV6A as a direct drop-in.


~Cheers~

 

[wavrider]

There ya go Sonar, Exit13 cleared up the confusion.
The schematic must be incorrect as no 6jg6a is in the print,

 

[BJ radionut]

The Phantom that Sonar has pictured is the triple stage model. 1 - 6JG6A into 3 - 6JE6C/6LQ6 into 6 - 6MJ6/6LQ6. The 6MJ6 is the industrial/military spec grade 6LQ6.

Usually, the 6JG6A is the first tube to get weak, especially if the tube consistently sees more than about 2.5W deadkey on AM, and 15W PEP on SSB. The tube has a max plate dissipation of 17W, so it's very easy to overdrive and potentially "cook" the tube.

You can substitute a 6KV6A as a direct drop-in.

Also Sonar...The 6MJ6/6LQ6/6JE6.... with 6 of those as the final stage...if your running on Ancient Modulation and showing 1000w or even on SSB....
Those tubes are not long for this world!
Max those should be run with drive level so the final PEP output should be NO MORE than 6-700 watts...PEP
Those tubes are rated at 67 watts each...but in amplifier configuration about 100-110w EACH...or they are going to COOK...
Just as a suggestion...
When those tubes were $10 each...sure run the S**T out of them...
But 6MJ6's now can run NIB ( RCA's or Sylvania's) from $40-$70 EACH...and have not been made since the LATE 70's...
So take care of them...also most of the power supplies in those D&A amps were marginal at best...Just big enough to get by...You waste a transformer in those just about the only way to fix it is find a parts amp...NEW ones will cost $200-$300 EACH to have wound so they will fit in same location.
You have got a clean nice unit there...but remember it's 30-40 years old now and lots of TLC is in order if you want to keep it around...
All the Best
Gary

 

[Sonar]

if you can post another pic of the amp, tube side and then the bottom side, hopefully the pic will be clear enough to see how the tube sockets are wired up in the amp.

This is the picture I posted a while back. Since then all caps have been replaced. Besides that it's still the same.

 

[Sonar]

Also Sonar...The 6MJ6/6LQ6/6JE6.... with 6 of those as the final stage...if your running on Ancient Modulation and showing 1000w or even on SSB....
Those tubes are not long for this world!
Max those should be run with drive level so the final PEP output should be NO MORE than 6-700 watts...PEP
Those tubes are rated at 67 watts each...but in amplifier configuration about 100-110w EACH...or they are going to COOK...
Just as a suggestion...
When those tubes were $10 each...sure run the S**T out of them...
But 6MJ6's now can run NIB ( RCA's or Sylvania's) from $40-$70 EACH...and have not been made since the LATE 70's...
So take care of them...also most of the power supplies in those D&A amps were marginal at best...Just big enough to get by...You waste a transformer in those just about the only way to fix it is find a parts amp...NEW ones will cost $200-$300 EACH to have wound so they will fit in same location.
You have got a clean nice unit there...but remember it's 30-40 years old now and lots of TLC is in order if you want to keep it around...
All the Best
Gary

Thanks for the information Gary. I wish I would've read your post before purchasing all the 6lq6's and the driver.
I'm going to keep them as I'll probably need them eventually.
I am going to replace the driver.
I got all 9 6lq6 plus another for $110 and the driver for $19. I can live with that. I'll let you know how it went. Thanks. 73

 

[Sonar]

Thanks for the information Gary. I wish I would've read your post before purchasing all the 6lq6's and the driver.
I'm going to keep them as I'll probably need them eventually.
I am going to replace the driver.
I got all 9 6lq6 plus another for $110 and the driver for $19. I can live with that. I'll let you know how it went. Thanks. 73

This is another picture I posted a while back. I will post some new ones after installing the new tubes. I'll also post the results of the retube.

 

[357]

The 1 6jg6 is just a dud to complete the filiment circuit.
You should PM nomadradio and get the heads up.
You can google the "twin peaks" thing too, you may not be tuned up properly.

http://www.worldwidedx.com/threads/d-a-pdx-400.23121/page-2#post-65771

 

[Sonar]

The 1 6jg6 is just a dud to complete the filiment circuit.
You should PM nomadradio and get the heads up.
You can google the "twin peaks" thing too, you may not be tuned up properly.

http://www.worldwidedx.com/threads/d-a-pdx-400.23121/page-2#post-65771

I actually mentioned in a previous post that the 6jg6 was there to complete the circuit.
I watched a YouTube video and the guy giving the tour of the phantom mentioned that.
He said if it lights up it's good.
The straight of that tube doesn't matter I guess since the one I purchased is already in the mail I'll keep it for a just in case.
Between you and the video i watched I'm convinced you're correct.
I know the other member who suggested the 6jg6 was a driver might be correct when the information is applied to another phantom.
d&a made so many configurations of the phantom and I wouldn't be surprised if some might use the 6jg6 as a first driver but I'm convinced this particular one doesn't.
I'll wait to see if anyone else weighs in before I install the replacement 6lq6's I bought. Thank you for replying. 73 ps I've been tunning this amp the same way since day one and saw the output drop over time. I'm fairly sure it's the tubes but will check out the link for tuning procedures.

 

[wavrider]

Thanks for posting the pics,
It seems the single tube is for the CW gimmick to try and make the amp legal for sale, looks like the green wire goes to the crystal socket on the front of the amp.
it may be required for filament voltage purposes.
For all purposes the tube is NOT any part of the amplifier circuit except for filament voltage.