12TUBE D&A PHANTOM 500 SCHEMATICS

[giboni]

I still have the amp, but want it re-wired for 24LQ6 tubes if anyone can get it done, otherwise I'll sell it for parts. has 12 tubes, triple stage, and its only for 10/11 meters, it does NOT have a band switch and I cant find a schematic except for CBtricks but theirs has the bandswich and only 10 tubes. You can find me as Ticket2Ride1 on AOL for faster replies. Thanks in advance.

I have done it several times.Re-wire to 24LQ6 & 31LQ6. Also replacing the Tank circuits etc.

Check out my current project. Converting a 12 tuber to a Warrior.

FedEx will be 53.00 each way. PM me on this forum.

Two versions of 12 tuber exist. Possibly more. I have both. The 2nd version sits in my daily ride.

Best 73s PuppetMaster

 

[Jimbo165]

I have a old 12 tuber D&A that is different than any other I have seen. Has a top cover and bottom cover plus has two tuners and grid screw on left side of amp plus two and switches on front. This is probably close to first ones built maybe??.

 

[giboni]

Cool

Certainly earlier than the cloth colored Stancor tranny's 12 tuber I have.

Very different case. It has a phono jack in rear. Have several of those black Stancors.

Taken from Mavericks that were cannibalized. I'll take some picks & post mine.

Possibly. The version that came after yours.

 

[nomadradio]

That is the very oldest version of the Phantom that I know about. Pretty sure I have seen only two of them in the 42 years I have had this job.

The removeable top cover is the first clue. The Stancor transformers with a catalog number stamped on them are the other clue.

By the time Ed DuLaney had boosted his production volume and changed to the slide-off wraparound cabinet he was having the transformers custom made, rather than buying catalog parts like you see in this one.

73

 

[Jimbo165]

nomadradio and gigoni I thought this was a early version when I bought it. It has surface rust all over but no holes or bad places. With tubes keys up in all positions but I have no power output . I will try to fix or get it fixed if not will sell it to someone that will restore it but on shelf for now.

 

[giboni]

12 tubers R the best !

Schematic might be helpful. If only. They used proper color coded wires.

 

[Jeremy Wendt]

I NEED TO KNOW WHERE I CAN FIND A SCHEMATIC FOR A 12TUBE PHANTOM 500.

Did you ever find a schematic for a 12 tube Phantom?

 

[nomadradio]

This is the one we have on file.

73

 

[Jeremy Wendt]

Thanks!!

 

[Jeremy Wendt]

What causes a humming sound coming from the speaker on a Browning golden eagle mark 3 receiver.

 

[oldtymer]

Some one who doesn't know the words to the song.
Could be bad electrolytic cap(s) were they ever replaced?

 

[Jeremy Wendt]

Yes they were replaced.
Can it be the filter cap on the top side?

 

[nomadradio]

Humming sound.

More than one possible kind of sound you can use that word to describe.

Does the pitch change when moving any of the knobs, or does the pitch of the sound stay the same all the time?

Asking whether the "hum" has a frequency of either 60 Hz or 120 Hz will help to pin down where it's coming from.

60 Hz usually comes from a bad tube or bad ground connection on a tube socket.

120 Hz comes from the full-wave rectifier feeding the high voltage into the tubes. Bad filter capacitors are the most-common cause.

But not necessarily the only one.

When the filter capacitors were changed, were ** ALL ** of them changed, or just the ones that tested bad that day?

Big difference. Too many tube radios arrive here with the description "It had the capacitors replaced".

Uh, by the owner, or by a horse-trader trying to make it work just well enough to unload?

Big difference in cost. The horse trader won't spend a dime to make it work any longer than it takes to sell.

Way too often we see one or more new capacitors simply tied into the circuit, or "scabbed", leaving the failed original part STILL CONNECTED TO THE CIRCUIT!

Fixes the "hum" it had that got him a cheap purchase price.

Doesn't fix the next three of those 40 to 50 year-old electrolytics that will fail the first week or month it goes back into service. Besides, leaving the failed old part in the circuit can lead to another headache if it shorts out inside later on.

We always replace the rectifier that feeds the radio's high-voltage, or "B+". We started doing that after a few radios with ALL NEW electrolytics came back in a week or so with the rectifier broken down. Now it gets upgraded along with the filter capacitors it feeds rectified DC into.

If **EVERY LAST, SINGLE ** electrolytic cap is new, they are probably not the root of the fault. If they are new, the rectifier deserves a look. Not so tough to test.

And if the description "caps were replaced" really means that several factory-original parts are STILL IN the power supply section, expect them to fail. A 120-Hz pitch from your "hum" points to them as the cause.

The word "hum" covers a lot of possible territory. Narrowing down which one of several kinds of "hum" noise you have will be the place to start.

73

 

[Jeremy Wendt]

The sound never changes, just the receiver plugged in with no mic connected turn on the power with the volume all the way down its humming sounds like a guitar amp.
It does not change when you play around with any of the knobs.

 

[nomadradio]

Probably the 120-Hz hum from the B+ voltage.

There is one tube that could do this to you. The 12AX7 tube at the left edge of the chassis. If you pull out that tube and the hum goes away, this tube could have a problem.

And if this doesn't change the sound at all, this makes it sound like either you still have original filters in the radio, or the B+ rectifier has gone bad.

I'm skeptical of the claim about all the filter caps being new. Makes it sound like some old ones are still in there.

73