Two late model D&A linear amplifiers Phantom Dual Power & PDX-400
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- เผยแพร่เมื่อ 10 ต.ค. 2024
- Well I failed to make the video short. The Phantom has a new home with a friend who is a responsible operator.
The SSB delay is running all the time in these amps. Therefore no switch to select it like in older versions. They're very much a low drive amp. Best driven with a under 20 watt peak. Sure they will do more with the hotter radios but the tubes won't last long. Especially the driver tubes. I forgot to show the President Lincolns output for the video. It was set at 3 watts of carrier and 18 watts peak.
Notice the metal plug on the face of the Phantom where the band selector switch was on some earlier versions. The face had already been punched for it which is a bit odd since it was punched for the crystal socket holes as well. Maybe they added the crystal socket holes to the existing die and later made a new die without the band selector hole? Of course the holes for the crystal socket might just have be drilled and not punched on the Phantom.
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In the 1970s I can remember seeing lots of ads for mail in
electronic courses in magazines. One of the schools mentioned the owner of D&A was a student and showed one of the amplifiers.
I believe most of us have learned the lesson about the high voltage in these tube type amps the hard way. Was bit a few times myself by sweep tubes amps when I was younger. The one that really made me very safety conscious when handling them was a no name all black cased amp with a bunch of 8908's in it. Something crazy like 1 driving 2 driving 7. Locally we called that amp Black Bart for many reasons. 73's Paul
I had a PDX 400 back in the 80's using 8950's. I was young and stupid and learned all about the danger of high voltage capacitors... the hard way. It is a lesson that has stuck with me.
Very thorough comparison of the 2 d&a phantom amps. I had a grey 12 tube Phantom that was converted to run a pair of 572B transmit tubes. That was one clean sounding amp, wish I still had it 🤓
Glad you liked the video. It ended up be much longer than I planned for it to be. Hopefully there will be some useful info in it for some. 73's Paul
Hey, another great video. No one ever goes into enough detail on amps. Keep up the good work!
The one tube sitting buy itself off from the side of the the drives in the PDX400 is another 6JG6 used for the CW circuit. As explained in my video you need it plugged in to complete the circuit for the filament voltage to the driver tubes. With it unplugged you will have no filament voltage to one of the drivers. It can be just a weak tube. It's only needed to complete the circuit.
Thanks. Which version of the amp? The old gray case Phantom, Dual Power early or late version, PDX400???
The older gray case units used a 6AQ5 for the keying circuit and 6LQ6's for the driver and finals. You can substitute 6JE6, 6ME6, and 6MJ6 in place of the 6LQ6 tubes. The Dual Phantoms power and PDX400 used the same tubes in the final section but varied what was used for drivers. Some used the 6JG6 for drivers while others used 6LQ6 like the older units.......... continued
Congrats on finding a mint unit.
My first was an old gray cased triple staged 10 tube. I acquired it used when I was in my early 20's. Served me well for many years.
Output seen from these, or any amp, is dependent on a lot of factors. On AM using a average reading meter I agree you will likely only see 300 to 400 clean watts from these. However if using a true peak meter, then PEP output will be 700 to 900 on AM. Course that gets into the old debate over PEP readings on AM...... 73's Paul
The last Phantom i had had all 6lq6 tubes... It was a good amp.
I have seen a few late Triple Stage Phantom D&As with selectible 40,20,15 and 10 meter tanks in them, but how many people really used these for 40 meters, or with CW? No one, and they finally succumbed to the FCC, and probably solid state linear "export" CB linear amps. I see a lot of conversions to 30LQ6, or 25LQ6 to save money. Someone just had a fairly decent Phantom for sale on Craigslist. I am not a huge fan of used sweep tube linear amps or even the sweep tube Yeasu Musen transmitters that were frequently used for bootleg 11 meter band. I picked up some 3000 volt Navy power transformer that will easily power a 10KW linear RF tube amp, if paired up. The guy that sold them was given an ultimatum by his wife, being their small children were running about the house, and his homebrew linear was just a terrifying looking cobbled together mess. Who, in their right mind, stings together 60 100 volt diodes in series on each leg of the secondary, and runs them down an open cabinet? LOL I have to wonder, "Were these D&As even intended for ham radio, or was their target market CB'ers??" Money is money, regardless of who's pocket you get it from. It all spends the same. 10 meters or 15 meters, my butt! The Yeasu Twins, were also routinely equipped with "funny crystals", and run as 100 watt CB rigs. It's not good for them, but you can jam 100 watts into a D&A 10 tube triple and get 1000, to1200+ Watts out. I am sure that rips and strips the cathode coatings inside the tubes, and heats those plates up really nicely. Nice find, and have fun with it. I was just not willing to part with $300 for a beat up D&A. I have those 3000 volt, 150 pound monster Navy power transformers, and some 8877s to play with, for now. D&A is not even really recognized as a piece of ham radio gear, by now, and I suspect that is, partly, why they had those issues with the FCC. Too bad. These are kinda cool. If I find one cheap enough, and I have nothing else going on, maybe someday, I'll get another D&A. I have my Extra Class license, but I bear no malice, or ill will toward the CB crowd. I have something to lose, called my license, but it's all good, and just have fun with it. Happy Christmas, everyone.
Looks ot me that an chock is burned up as well going to the High and low
power switch.
The CW circuit tube in the PDX400 might be a 6LQ6 type and not a 6JG6 type as I originally stated. Difficult to remember now after all these years.
Great video, you do an excellent job. Thank You'
continues..........The 6JG6 can be substituted with the 6JT6 or 6KV6. The 6KV6 is the better choice. The 6JR6 might work as well but I don't remember for certain. If there are B+ caps and parasitic suppressors for the driver tubes on the top side of the chassis then it used the 6LQ6 type tubes. If there are no B+ caps and such for the drive section then it used the 6JG6 type tubes. Bear in mind some of these amps have been modified in various ways & not all use the original tubes. 73's Paul
I'm the owner of a varmint XL 600 base plug it in works good but I got one problem I've got filament for the driver tubes 6kv6 but not for the four finals 6LF6 do you think it might be a crack in the board any information would help. About all brand new tubes 98%
I HAVE A D&A DUEL POWER 8 TUBE AND BOTH NEEDLES PIN IN TRANSMIT MODE. PLEASE HELP....A WIRE ON THE TOP COIL CAME OFF AND BLEW THE FUSE. THATS WHEN THIS NEEDLE THING HAPPEND.
You sound like dear slayer
You can email directly through the TH-cam email system.
Do u have an email questions about a phantom I have??
Email reply sent. I don't have the info so if anyone else does please contact him.
Offense taken. Seems you're another internet or radio Rambo type. It's easy to insult someone from the other side of a keyboard or a microphone. Not so much so in person.
Love that D&A PDX 400! Drove it hard with a Brute 75. Just keep some spare parts around!!
I added a 2nd cooling fan on the right. Really helps cooling the tubes! They weren't cheap way back then!
Works superb with 6MJ6's. Much better than 6JE6A's...
I want of these...PLEASE!!!
Do u have an email questions about a phantom I have??