This old Cyclotron
Bob
When PG&E and the State of CA asked us to run "off peak hours" to reduce the Campus electrical footprint, you know Jerry and I just had to check. With WLD & WHD pumps running and the main magnet trimmed for 67.5 KeV..... RF Section off we were clocking 1.2Mw from the grid.
The final drive RCA 6949 would have required 1100A @ 5V across the filaments, which you may recall there were 24 in parallel per tube. Hardly worthy of note, in the greater scheme of things
Nelson may have photos of one of those tubes in pieces, when Econco commented that "God doesn't have enough money for us to rebuild that tube!"
I perhaps have photos of the tube hanging from the small hook on the bridge crane, ready to socket
And for the record, Bob; you introduced me to Nelson....... Thank you!
Bob
When PG&E and the State of CA asked us to run "off peak hours" to reduce the Campus electrical footprint, you know Jerry and I just had to check. With WLD & WHD pumps running and the main magnet trimmed for 67.5 KeV..... RF Section off we were clocking 1.2Mw from the grid.
The final drive RCA 6949 would have required 1100A @ 5V across the filaments, which you may recall there were 24 in parallel per tube. Hardly worthy of note, in the greater scheme of things
Nelson may have photos of one of those tubes in pieces, when Econco commented that "God doesn't have enough money for us to rebuild that tube!"
I perhaps have photos of the tube hanging from the small hook on the bridge crane, ready to socket
And for the record, Bob; you introduced me to Nelson....... Thank you!
For you toobz guys
the 6949
http://www.nj7p.org/Tubes/PDFs/Frank/049-RCA_Cuningham/6949.pdf
sorry to get off topic
the 6949
http://www.nj7p.org/Tubes/PDFs/Frank/049-RCA_Cuningham/6949.pdf
sorry to get off topic
Addendum to "THIS OLD CYCLOTRON" I see Dr. Flocchini posted a link to the Davis 76" machine which was built from the remains of the Berkeley 60", famous in certain circles, and with good reason.
The Crocker Home page has a photo... lots of hoses and in the foreground a linear rail.
At the end of the linear rail is the "Beam Probe" In operation the operator run the beam probe in and out and maps the energy of the beam as it circulates inside the dees at about 60% of the speed of light. Knowing the energy they then then pick the beam off and extract it at the required energy, it's quite the "Black-Art".
The red hoses in the background carry ultra pure cooling water to various focusing elements. A 1m column of this water needs to stand off the 60Kv sitting on the plate of the final drive
(polished water makes vile coffee)
The Crocker Home page has a photo... lots of hoses and in the foreground a linear rail.
At the end of the linear rail is the "Beam Probe" In operation the operator run the beam probe in and out and maps the energy of the beam as it circulates inside the dees at about 60% of the speed of light. Knowing the energy they then then pick the beam off and extract it at the required energy, it's quite the "Black-Art".
The red hoses in the background carry ultra pure cooling water to various focusing elements. A 1m column of this water needs to stand off the 60Kv sitting on the plate of the final drive
(polished water makes vile coffee)
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GEEZ addendum to the addendums
RCA 6949 was a WWII sonar tube, that was later co-opted by the radio telescope guys, principally Arecibo... nobody is going to remember that.
They are however likely to remember the border blaster AM Stations running out of Mexico and broadcasting into and all across North America with surplus JAN tubes XERF / XERB ancestral home of "Wolfman Jack"
So yes off topic, but somewhat audio related
RCA 6949 was a WWII sonar tube, that was later co-opted by the radio telescope guys, principally Arecibo... nobody is going to remember that.
They are however likely to remember the border blaster AM Stations running out of Mexico and broadcasting into and all across North America with surplus JAN tubes XERF / XERB ancestral home of "Wolfman Jack"
So yes off topic, but somewhat audio related
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so , for all regular Greedy Boyz , that was blast from the past , and we are not even aware of fact how Peanuts we are , comparing to these modest Geezers ......
OK , I was braver when I was a Kid , but these days toying with sand
(nothing is off topic when I'm present in thread
)
OK , I was braver when I was a Kid , but these days toying with sand
(nothing is off topic when I'm present in thread
)per ZM "(nothing is off topic when I'm present in thread )"
Much appreciated - brought back memories of fun times 🙂
for Dennis - I think the Amplimos guys did a 2sk180 circlotron
probably beyond me but I will check it out
Much appreciated - brought back memories of fun times 🙂
for Dennis - I think the Amplimos guys did a 2sk180 circlotron
probably beyond me but I will check it out
though ........ toying with SITs is craving for dominant 2nd ......... and if you want that with circlotron , you must fight inherent symmetry , to achieve the same
go back to post #50 , and look at THD Spectra and levels of one of the sweetest and best sounding amps around , at least to my knowledge
that amp practically started all my recent sissy/silly/ness
blame Pa, as always
........ dunno why I just remembered old blog post of mine ...... but I till have this case empty , just black powder-coated in meantime ........ Babelfish (most probably J2) B17 edition – case for future amp | Zen Mod Blog
🙂
go back to post #50 , and look at THD Spectra and levels of one of the sweetest and best sounding amps around , at least to my knowledge
that amp practically started all my recent sissy/silly/ness
blame Pa, as always
........ dunno why I just remembered old blog post of mine ...... but I till have this case empty , just black powder-coated in meantime ........ Babelfish (most probably J2) B17 edition – case for future amp | Zen Mod Blog
🙂
You are right - dominant second !!!
Circlotrons as I recall (its been awhile since I read Mike Rs post) are dominant third -
The 180s will find a project or will be kept as back-ups
180 SissySit????
Circlotrons as I recall (its been awhile since I read Mike Rs post) are dominant third -
The 180s will find a project or will be kept as back-ups
180 SissySit????
Now that would be fun
My first Pass Amp was the ZenLite - Kent had it at BA2019
Is the modified circuit in a thread? I am having search problems
Thanks
Bob
My first Pass Amp was the ZenLite - Kent had it at BA2019
Is the modified circuit in a thread? I am having search problems
Thanks
Bob
Hi Bob,
The L'amp articles can be found on Mike's page (see bottom):
Articles | AudioMaker
No double ZM would approve the inductor-loaded version. 🙂
Cheers,
Dennis
The L'amp articles can be found on Mike's page (see bottom):
Articles | AudioMaker
No double ZM would approve the inductor-loaded version. 🙂
Cheers,
Dennis
I bought two 2SK180Ds yesterday from an ebay merchant, and I was actually thinking about using them single ended with choke loading. I just can't stop.🙂
I have a Hammond 193V loaded 2SJ28 L'Amp that I am thinking of repurposing for the 2SK180Ds. I will need a new power transformer and more heatsinking but I will be able to use the rest of the parts.
I did some LTSpice simulations, trying MR's operating point from his light bulb L'Amp (Vds 36V Iq 2.1A), and also after some playing around, Vds 29V and Iq 3.0A.
When I get my 2SK280Ds, I will re-rig the amp and do some experimenting with operating points. I have a variac so I will be able to rewire the existing transformer for higher voltage and use the variac to adjust the Vds and do some experimenting.
The LTSpice results for MR's resistive load operation point used in choke loading at 10W had 3rd harmonic slightly higher than the 2nd harmonic, and also had a lot of higher order harmonics. The other operating point gave THD that was a bit higher but the 2nd harmonic was dominant.
In-situ measurements will be done when I get the 2SK180Ds and hopefully I will then be able to decide on Vds and Iq.
I have a Hammond 193V loaded 2SJ28 L'Amp that I am thinking of repurposing for the 2SK180Ds. I will need a new power transformer and more heatsinking but I will be able to use the rest of the parts.
I did some LTSpice simulations, trying MR's operating point from his light bulb L'Amp (Vds 36V Iq 2.1A), and also after some playing around, Vds 29V and Iq 3.0A.
When I get my 2SK280Ds, I will re-rig the amp and do some experimenting with operating points. I have a variac so I will be able to rewire the existing transformer for higher voltage and use the variac to adjust the Vds and do some experimenting.
The LTSpice results for MR's resistive load operation point used in choke loading at 10W had 3rd harmonic slightly higher than the 2nd harmonic, and also had a lot of higher order harmonics. The other operating point gave THD that was a bit higher but the 2nd harmonic was dominant.
In-situ measurements will be done when I get the 2SK180Ds and hopefully I will then be able to decide on Vds and Iq.
Attachments
C&C - Correspondence and Chokes
had sore back yesterday , so spent most of day just laying with e-book reader
today little better , but I had short trip (being a slave to your own female teen , thing familiar to most of us .... ) , just got back , so I must being friendly with e-book reader again , to recuperate and not have sore back tomorrow again
have some pending correspondence with several Greedy Boyz , will do that this night , so no worries
choke - point of changing approach (and in general) - getting lowest possible THD , with still dominant 2nd ; so , if it's possible to squeeze max. 0.5-0,6% THD 1W/8R , efforts are in good direction ; if not , try harder
lhquam is Da Man , regarding methodical and systematic approach with brain; his latest thread worth reading and re-reading
me, I'm more of systematically hysterical brainless approach
indra - always finding important and new itsybitsies ...... I have some monstrous 110/220Vac autoformers , will maybe try to see what I'm getting with 32R load with 2SK180 iteration,still sitting on the bench
had sore back yesterday , so spent most of day just laying with e-book reader
today little better , but I had short trip (being a slave to your own female teen , thing familiar to most of us .... ) , just got back , so I must being friendly with e-book reader again , to recuperate and not have sore back tomorrow again
have some pending correspondence with several Greedy Boyz , will do that this night , so no worries
choke - point of changing approach (and in general) - getting lowest possible THD , with still dominant 2nd ; so , if it's possible to squeeze max. 0.5-0,6% THD 1W/8R , efforts are in good direction ; if not , try harder
lhquam is Da Man , regarding methodical and systematic approach with brain; his latest thread worth reading and re-reading
me, I'm more of systematically hysterical brainless approach
indra - always finding important and new itsybitsies ...... I have some monstrous 110/220Vac autoformers , will maybe try to see what I'm getting with 32R load with 2SK180 iteration,still sitting on the bench