STRANGE TRIPLE STAGE PHANTOM

[Stellasstillarat]

Has anyone ever seen this triple stage phantom?
There's no band switch or switch that's located on the back of the amp that must be switched on when using the amp in any mode besides the 10 or 15 meters.
It looks to have been deleted from DnA. There's no singh it ever existed. No covered up hole.
The band switch has been deleted. factory delete? I'm not sure (I think) unlike the missing switch on the back there's a cap covering the hole where the band switch would've been located.
It looks to be factory deleted as the plugs that covers the hole where the band switch should be is a very good
match (paint wise perfect) and just looks factory to me.
There's also no ssb/AM switch.
There is a switch marked spot tuned. Does anyone know what this is?
This amp was used on 11 meters AM for many years but never tried on ssb.
Might it have one of those transistors inline with the relay alowing for it to operate correctly in ssb?
It does work excellent on AM.
I hope these pictures make it possible for someone to answer some or all the questions. If by some small chance this anp doesn't work on ssb (which would really surprise me) can it be modified to work on ssb. I'm actually very happy using it on AM but I've never seen a phantom that doesn't operate on ssb. Thanks.

 

[Atlasta]

Interesting item. When I saw the crystal slot on the front end I thought it was one of the later Phantoms that D&A tried to pass off as a 15 meter amateur transmitter but as I recall those carried the PDX prefix in the name. It appears to be some type of hybrid between the the two. Perhaps a prototype? Could you post some photos of the rear such as the I/O connections, any rear lettering- does it have a serial number?

Might be interesting to see the inside. The 'spot' switch is where the AM / SSB switch should be- is it a momentary switch? Have you tried it on sideband? Does it chatter?

The lack of a band switch on the front is confounding, especially since it still has the 10-15 / 20-40 switch on the back.

My gut tells me someone modded this amp which isn't all that unusual as many owners did just that trying to squeeze every last watt out of it. This one appears to have been done to a high standard based on it's outward appearance. Let's see what it looks like inside and underneath!

 

[Stellasstillarat]

View attachment 15877 View attachment 15878 View attachment 15878 I haven't tried it on ssb but when tunning and operating in AM the spot tuned switch is in the off (down) position.
Sorry if i led you to belive it has the switch that would normally have to be in the off position when being used in 15 or 10 but as you can see in the pictures i added the place where the switch should be (next to the grid control) has the same courius plug
like the one on that covers the hole where the band selector should be.
Paint wise it's macthed so perfectly it looks factory placed.
The serial number sticker does hold the phantom name as well a serial number. The The antenna input is marked antenna like any amp I've ever seen but the input unlike mos marked trans. is marked vfo. Thanks for your intrest and help.

Interesting item. When I saw the crystal slot on the front end I thought it was one of the later Phantoms that D&A tried to pass off as a 15 meter amateur transmitter but as I recall those carried the PDX prefix in the name. It appears to be some type of hybrid between the the two. Perhaps a prototype? Could you post some photos of the rear such as the I/O connections, any rear lettering- does it have a serial number?

Might be interesting to see the inside. The 'spot' switch is where the AM / SSB switch should be- is it a momentary switch? Have you tried it on sideband? Does it chatter?

The lack of a band switch on the front is confounding, especially since it still has the 10-15 / 20-40 switch on the back.

My gut tells me someone modded this amp which isn't all that unusual as many owners did just that trying to squeeze every last watt out of it. This one appears to have been done to a high standard based on it's outward appearance. Let's see what it looks like inside and underneath!

 

[Atlasta]

Odd. I assume that it does not the the 'BTL' option- that was a very poorly designed receive preamp that more often than not didn't work- even when new.

The 'VFO' label (most versions said ' Input') is telling. It's another feature found on the so-called 'amateur transmitters' along with the 'key' input- designed for a manually-operated foot switch.

The tan paint is fairly easy to match so the color-keyed hole covers isn't much of an indicator. I did find one other triple-stage Phantom online that has the same features as yours :http://www.fvstore.com/D-amp-A-Phantom-Triple-Stage-Amplifier/p1190951.html Lots of good photos if you scroll down.

After further review I'm more confident that this amp is probably a transition model. D&A was known for making amps from whatever they had a lot of on any given day and they played a lot of games trying to stay one step ahead of the FCC. It's why no two D&A amps are exactly the same. I'd love to find some old production records of how many (and how many versions) of each amp they made, but I'm sure that information has been lost to history.

As for the 'spot' function: The last time I saw anything like a spot tune it was on a Siltronix 1011. You held up the switch and then tuned the PA on the radio, eliminating the need to holler AUUUUUUUUDIIIIIIOOOOOOOO into the mike. I assume this function was carried out with some type of internal oscillator. Can't imagine why anyone would build something like that into a D&A though.

Would still like to see pix of the inside, particularly where the band switch on the front should be. I'm curious how many taps are on the tank coil.

Hope this helps.

 

[Stellasstillarat]

You are correct. No (btl) preamp on this amp. As it was a $15 option and realy worked like crap as most if not all amplifier preamps do. I'm assuming the original buyer knew this and saved himself $15. I've learned that a sopt tuned switch is the switch that accually keyed up cw transmitters. I think this spot tuned switch was probably one of the many ploys used by DnA to try and convince the fcc it wasn't an 11 meter amp but infact a cw transmitter hence the crystal input located on the face of this phantom. I'm becoming convinced this amp may have been order by the original owner without the band selector or 20/40 meter switch that is normally placed on the rear of the amp because he knew it was only gonna be used on 10 (lol). If this requires from DnA was possible the owner would've had to tell them 10 as DnA never would've buit one for someone requesting anything for 11 meters. After all 10 meter transmitters were and still used by old timers. I'm sure the nostalgia factor come into play as any modern hf will operate cw not to mention all the other modes and features. I promise to take and post pictures of the inside top and bottom as soon as I've a reson to remove the cover. By the way the switch marked spot tuned is just what it is in all the other phantoms. Off operates the AM mode and spot tuned is mearly the ssb operating mode. Thaks. Please. If anyone has definite info on this amp as im speculating. QUOTE="Atlasta, post: 523198, member: 19597"]Odd. I assume that it does not the the 'BTL' option- that was a very poorly designed receive preamp that more often than not didn't work- even when new.

The 'VFO' label (most versions said ' Input') is telling. It's another feature found on the so-called 'amateur transmitters' along with the 'key' input- designed for a manually-operated foot switch.

The tan paint is fairly easy to match so the color-keyed hole covers isn't much of an indicator. I did find one other triple-stage Phantom online that has the same features as yours :http://www.fvstore.com/D-amp-A-Phantom-Triple-Stage-Amplifier/p1190951.html Lots of good photos if you scroll down.

After further review I'm more confident that this amp is probably a transition model. D&A was known for making amps from whatever they had a lot of on any given day and they played a lot of games trying to stay one step ahead of the FCC. It's why no two D&A amps are exactly the same. I'd love to find some old production records of how many (and how many versions) of each amp they made, but I'm sure that information has been lost to history.

As for the 'spot' function: The last time I saw anything like a spot tune it was on a Siltronix 1011. You held up the switch and then tuned the PA on the radio, eliminating the need to holler AUUUUUUUUDIIIIIIOOOOOOOO into the mike. I assume this function was carried out with some type of internal oscillator. Can't imagine why anyone would build something like that into a D&A though.

Would still like to see pix of the inside, particularly where the band switch on the front should be. I'm curious how many taps are on the tank coil.

Hope this helps.[/QUOTE]

 

[Stellasstillarat]

Ok. Here's the pictures of the strange phantom. Phantom.
couldn't have been a better choice of name. Especially for thid one. This may possibly be a phantom, phantom.

Interesting item. When I saw the crystal slot on the front end I thought it was one of the later Phantoms that D&A tried to pass off as a 15 meter amateur transmitter but as I recall those carried the PDX prefix in the name. It appears to be some type of hybrid between the the two. Perhaps a prototype? Could you post some photos of the rear such as the I/O connections, any rear lettering- does it have a serial number?

Might be interesting to see the inside. The 'spot' switch is where the AM / SSB switch should be- is it a momentary switch? Have you tried it on sideband? Does it chatter?

The lack of a band switch on the front is confounding, especially since it still has the 10-15 / 20-40 switch on the back.

My gut tells me someone modded this amp which isn't all that unusual as many owners did just that trying to squeeze every last watt out of it. This one appears to have been done to a high standard based on it's outward appearance. Let's see what it looks like inside and underneath!

 

[Spiderleggs]

I have one just like it. It has four 6kv6a's and six 6lq6's.

 

[Atlasta]

That's one of the cleanest Phantoms I've seen in some time. Looking at the tank coil it is much smaller than the one on the band switch- equipped Phantoms. Like all Phantoms the tube right behind the final load control is too close to the capacitor. It needs to be inserted at a slight angle toward the rear so as not to touch the cap- if this isn't done the glass envelope WILL crack. It wasn't a problem with the original D&A tubes as they were taller and a bit thinner than the more common 6LQ6 replacements.

As I recall these amps did not operate on 11 out of the box. I think the procedure was that you bought the amp and a few days later a letter arrived in the mail with instructions on how to make it work on 11.

This one appears to be in a 3 driving 6 combo.

 

[Stellasstillarat]

All ten tubes in this particular phantom are DnA marked Sylvania's. Now wheather the original owner had the for site to purchase replacements I don't know.
I'm not even sure if one could purchase an extra set from DnA.
In the case one couldn't purchase the DnA labeled Sylvania's, Rca or which ever tubes they decided to install at any particular build period then I'm gonna assume these are the very tubes that a DnA worker put in this amp at the time it was built.
The best advice I've taken away from mostly every member of this site as far as amps go, is driving your amps at 11/2 watts is the best way to operate low drive cb amplifiers.
Every manual to every amp I own suggest's that 4 watts drive is basically the benchmark.
I've never driven amps with more than 21/2. Imo it's not nesessery. Loafing amps weather transistorized or tube at 11/2 will no doubt (in most cases) leed to the longevity of components. And that advice has worked great for me.

That's one of the cleanest Phantoms I've seen in some time. Looking at the tank coil it is much smaller than the one on the band switch- equipped Phantoms. Like all Phantoms the tube right behind the final load control is too close to the capacitor. It needs to be inserted at a slight angle toward the rear so as not to touch the cap- if this isn't done the glass envelope WILL crack. It wasn't a problem with the original D&A tubes as they were taller and a bit thinner than the more common 6LQ6 replacements.

As I recall these amps did not operate on 11 out of the box. I think the procedure was that you bought the amp and a few days later a letter arrived in the mail with instructions on how to make it work on 11.

This one appears to be in a 3 driving 6 combo.

That's one of the cleanest Phantoms I've seen in some time. Looking at the tank coil it is much smaller than the one on the band switch- equipped Phantoms. Like all Phantoms the tube right behind the final load control is too close to the capacitor. It needs to be inserted at a slight angle toward the rear so as not to touch the cap- if this isn't done the glass envelope WILL crack. It wasn't a problem with the original D&A tubes as they were taller and a bit thinner than the more common 6LQ6 replacements.

As I recall these amps did not operate on 11 out of the box. I think the procedure was that you bought the amp and a few days later a letter arrived in the mail with instructions on how to make it work on 11.

This one appears to be in a 3 driving 6 combo.

 

[StrangeBrew]

View attachment 15930
The best advice I've taken away from mostly every member of this site as far as amps go, is driving your amps at 11/2 watts is the best way to operate low drive cb amplifiers.
....

Not an expert here but I've always been of the opinion that what comes out of the amp is more important than what goes in, I just used whatever drive gives the output wattage I'm looking for.

Do you know how much that thing is supposed to put out?

 

[Atlasta]

One of the great myths of the D&A Phantom is that it is a 1,000 watt amp. No, it isn't. Going by D&As own information the triple-stage Phantom was rated at 1375 watts INPUT. Assuming 60% efficiency this should give an output of around 850 watts max.

Will they do 1,000? It can sure look that way on some meters. But to do that you would have to drive the snot out of them insuring a dirty, splattery signal and oh yeah- you will be replacing those tubes a LOT faster.

In the old days (before high-output radios) we would put a JB 75 modulator between the radio and the amp. That sure made them swing but the price was more rapid tube replacement.

I run mine with about a 4 w dead key and peaking around 8 watts (around 14 w PEP on SSB) On AM this give me a resting carrier of around 450 w with peaks hitting around 600w. On SSB I've seen it hit around 850 but that's the max.

As stated above, an amp is just going to give you more of whatever you put into it. Clean in = clean out. Run it below it's maximums and it should give years of service. I let mine loaf along and haven't had to replace a tube in about 3 years- except for that one tube behind the final load control!

 

[ExitThirteen]

That's a 1 driving 3 driving 6, hence the "Triple Stage" moniker. Since the single tube in the first stage is a 6JG6A, don't exceed 15W maximum PEP into the amp. That tube is rated at a max plate dissipation of 17W, as a rule of thumb you NEVER want go past 100% of your max plate dissipation on your input.

Beautiful amp, by the way... making me jealous!

~Cheers~

 

[Stellasstillarat]

I drive mine with 11/2 swinging to 10 and see and see about 300 dead key and hit a cunt hair below 1000.
On ssb with 12/14 it swinghfs to 1150. Between the crappy workman meter and the 60% efficiency I'd say my output is very close to your suggested output.

I get excellent audio reports with no over driving gargeling with razor blades sounding modulation. The only thing that I won't do is drive it with 4 watts.

I think the difference between the 11/2 and 4 is I fear the 4 will eventually lessen the life of the tubes .
The 4 or 11/2 imo is neglagable on the other end. And at the price of those tubes i just feel more comfortabel driving it at 11/2.
I drive all my amps at this dead key. Until i joined this site i used to drive amps at 21/2. I always was suspicious of almost every amp manual suggesting 4-6.
I think they need to substantiate their over rated input/output ratings buy having the owner say "it does do the per manual suggested wattage. I think the word
loaffing is the key to having tubes last as long as they posibly can and to me that's important.

Spending $500 on an amp that maybe would go for $200 without tubes is insane. Thanks for the information and although I'm tempted to give the 4 watt drive a try to see the difference I belive it will do very close to what yours does so I'll just stay with the 11/2 Thaks for all the info . Happy DX'ING

One of the great myths of the D&A Phantom is that it is a 1,000 watt amp. No, it isn't. Going by D&As own information the triple-stage Phantom was rated at 1375 watts INPUT. Assuming 60% efficiency this should give an output of around 850 watts max.

Will they do 1,000? It can sure look that way on some meters. But to do that you would have to drive the snot out of them insuring a dirty, splattery signal and oh yeah- you will be replacing those tubes a LOT faster.

In the old days (before high-output radios) we would put a JB 75 modulator between the radio and the amp. That sure made them swing but the price was more rapid tube replacement.

I run mine with about a 4 w dead key and peaking around 8 watts (around 14 w PEP on SSB) On AM this give me a resting carrier of around 450 w with peaks hitting around 600w. On SSB I've seen it hit around 850 but that's the max.

As stated above, an amp is just going to give you more of whatever you put into it. Clean in = clean out. Run it below it's maximums and it should give years of service. I let mine loaf along and haven't had to replace a tube in about 3 years- except for that one tube behind the final load control!

That's a 1 driving 3 driving 6, hence the "Triple Stage" moniker. Since the single tube in the first stage is a 6JG6A, don't exceed 15W maximum PEP into the amp. That tube is rated at a max plate dissipation of 17W, as a rule of thumb you NEVER want go past 100% of your max plate dissipation on your input.

Beautiful amp, by the way... making me jealous!

~Cheers~

One of the great myths of the D&A Phantom is that it is a 1,000 watt amp. No, it isn't. Going by D&As own information the triple-stage Phantom was rated at 1375 watts INPUT. Assuming 60% efficiency this should give an output of around 850 watts max.

Will they do 1,000? It can sure look that way on some meters. But to do that you would have to drive the snot out of them insuring a dirty, splattery signal and oh yeah- you will be replacing those tubes a LOT faster.

In the old days (before high-output radios) we would put a JB 75 modulator between the radio and the amp. That sure made them swing but the price was more rapid tube replacement.

I run mine with about a 4 w dead key and peaking around 8 watts (around 14 w PEP on SSB) On AM this give me a resting carrier of around 450 w with peaks hitting around 600w. On SSB I've seen it hit around 850 but that's the max.

As stated above, an amp is just going to give you more of whatever you put into it. Clean in = clean out. Run it below it's maximums and it should give years of service. I let mine loaf along and haven't had to replace a tube in about 3 years- except for that one tube behind the final load control!

 

[Stellasstillarat]

Thanks exit thirteen. This is excellent info. Just to make sure I'm understanding.
Since the 6JG6A is the initial driver and is rated at 17 watts max plate dissipation. The driving output (pep) should not exceed the rated plate dissipation of that 17 watts and would be best advised to drive at an output that's lesser then the rated output of an initial driver? Hypocriticaly if the 6JG6A's max plate dissipation was 30 watts. it would be advisable to drive the amp with less than 100% of that rated 30 watts? Say 25-27? Am I understanding correctly and if so, Is this a rule of thumb that would be best to apply to all amplifiers?

That's a 1 driving 3 driving 6, hence the "Triple Stage" moniker. Since the single tube in the first stage is a 6JG6A, don't exceed 15W maximum PEP into the amp. That tube is rated at a max plate dissipation of 17W, as a rule of thumb you NEVER want go past 100% of your max plate dissipation on your input.

Beautiful amp, by the way... making me jealous!

~Cheers~

 

[ExitThirteen]

Yes, you are correct. I like to run typically 70-75% of the tube's maximum plate dissipation, but that's just me. And this would apply to all sweep tube amps.

That being said, if you had 4 6LQ6's, with no driver tube, you could hit them with 120W absolute max PEP, as one 6LQ6 is rated at 30W max plate dissipation. Some of your ham amps, like the Amp Supply 1000NT and the Dentron GLA-1000B, run 4 - 6LQ6's, and they are designed to be used with an HF rig that can put out 100W PEP on SSB.

As a general rule tho, especially on sweep tubes, never exceed maximum plate dissipation on input. Also as a general rule. AM is very hard on sweep tubes, because of the deadkey. So, the lower the deadkey on AM, the longer life your tubes will have. SSB runs a very low cycle duty, about 15-20%, so you're not hitting the tubes near as hard on SSB, because there is no deadkey on SSB, only modulated output.

~Cheers~