D&A phantom 500 12 tube

Discussion in 'Amateur Radio Amplifiers' started by 17W1517, Jun 8, 2015.

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  1. 17W1517

    17W1517 QRZ Member

    Great web site folks! I'm looking for a schematic that covers the older D&A 12 tube phantom 500 amplifier. I've gone as far as I could without a schematic, but I've reached my high water mark. About 25 years ago I moved from Cleveland to Cincinnati leaving my radio equipment for my brother to use. When I arrived back a year later, most of my equipment was gone including a like new Browning Eagle mark IV with a gold eagle D-104, my phantom 500 and a slew of microphones, meters, etc. My brother knew nothing about any of it. 25 years later talking to a few local folks on the radio, I got the amp back for free since I was able to identify it. The guy I got it from acquired it for parts and paid nothing for it. There were some parts missing but there was enough to put it back together. I acquired 4 extra tubes that were better than 75% so all the tubes on average are about 75% and none of them less than 70%. If anyone has this schematic, I would greatly appreciate it!

    Thanks in advance!
    KR2C likes this.
  2. K7KBN

    K7KBN Ham Member QRZ Page

    Now THERE'S an old call! Las Vegas High School was 11QØØ82 in the very early 1960s.
  3. WG7X

    WG7X Premium Subscriber QRZ Page

    Not to put too fine a point on this, but this is a web site for licensed Amateur Radio operators.

    Some of the extremely helpful folks here will undoubtedly assist you, but that is because they are very nice folks. You might find a more like minded group on a CB website.

    What you have there is a CB amp that some folks will know something about, personally, I think that the best thing that you should do with it is throw it in a dumpster where it can be disposed of properly.

    Not that I am biased or anything...

    73 Gary
    KZ4KX likes this.
  4. AF6LJ

    AF6LJ Ham Member QRZ Page

    Sorry but unless you can prove you have a valid amateur radio license I wouldn't be able to help....

    But I will give you some free advice;
    Don't bother, nearly all the parts are next to impossiable to get, the tubes now run on the order of eighty dollars a pair.
    You are much better off spending a few hours learning how to get your technician license and join the rest of us on the ham bands.
  5. AB8RO

    AB8RO Ham Member QRZ Page

    Please don't put that thing on the air. That said, there has been some discussion in the past about similar (if not the same) designs and the consensus is that there's no practical way whatsoever to parallel twelve sweep tubes at 27 Mhz and get a clean signal.
  6. KA0HCP

    KA0HCP XML Subscriber QRZ Page

    www.CBtricks.com has the best collection of CB manuals and schematics. I didn't find a Phantom 500, but they do have a manual for D&A Phantom Triple Stage
  7. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    CBers don't care about clean signals, and I don't really care what they do if they stay below 28 MHz...evidently, FCC doesn't really care either.:p
    KZ4KX likes this.
  8. AA7QQ

    AA7QQ Ham Member QRZ Page

    Heck, I cared about a clean signal as a CBer... I had a ham put my 16 transistor homebrew amp (With LPF & Class AB1) through the wringer. A tad of tweaking & it was "Better than anything you can buy on the ham market". I built one for him, too...

    KK4RSV likes this.
  9. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    Describe better and what equipment was used to determine that.
  10. AA7QQ

    AA7QQ Ham Member QRZ Page

    He used a HP spectrum analyzer along with a 2 tone test. It was 1984 & I was 15 years old. I cannot remember the exact numbers. I do know that at 800 watts, it was well within published specs at the time. It was 16 srf2072 transistors. The filtering was a 5 pole chebyshev (Better than the drake LPF I had on it to start). I am having it delivered to me by a friend that was storing it for the past 15 years. When I get it back, I will go through it & test it again to ensure it's still clean.Also coming is a "Texas Star" sweet 16 that I had switchable bias for class C(AM/FM & AB for SSB. That will do limit. I was using my homebrew amp at my house with 2 8D batteries & a 6.5 HP B&S motor driving a 65 amp Chrysler alternator. Only TVI I had was a Panasonic clock radio next door, but a walkie talkie could wipe that out. To my knowledge, it was the first 16 transistor amplifier.
    I will say that the reason I taught myself how to build it clean was from having a Dentron amp that gathered me the wrath of every neighbor for an 1/8 mile. Also, my scoutmaster followed the splatter down from 10 meters, recognized my voice & called me to let me know I had KP for a year of campouts.

    WB1E likes this.

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