KD7YQM
Member
Posts: 71
|
 |
« on: August 07, 2008, 12:10:43 PM » |
|
I recently acquired this bad boy and I really can't think of any way to do any preliminary testing on it without a $400 socket.
I've checked the usual continuity of filament and shorts between elements and all looks good.
Another thing is that this thing will draw 75 amps @7.5v.
Not exactly an easy to find transformer.
Sounds more like a welder;)
Thanks for any ideas.
Dennis
|
|
|
|
|
Logged
|
|
|
|
|
K4DPK
|
|
« Reply #1 on: August 07, 2008, 02:33:41 PM » |
|
Dennis...
Is that a coaxial base?
I have several rings from large sockets.
Give me the diameters and I'll see if I have the rings/finger stock that fit. I could send them out just to test.
Phil C. Sr.
k4dpk
|
|
|
|
|
Logged
|
|
|
|
KD7YQM
Member
Posts: 71
|
|
« Reply #2 on: August 07, 2008, 02:54:08 PM » |
|
Hi Phil
Yes it is a coaxial base. The recommended socket is the SK300A. There's one on ebay for $400. Such a deal.
Eimac gives the ID dimensions for the filament connections as 1.9 inches for the inner and 3.17 inches for the outer contact.
The screen OD is about 4 inches and the grid OD is 3.8 inches.
Let me know what you have and what you want for it. Maybe I could build a socket cheaper. Doubtful though. thanks Dennis
|
|
|
|
|
Logged
|
|
|
|
|
K4DPK
|
|
« Reply #3 on: August 07, 2008, 05:35:36 PM » |
|
Dennis...
Send me an e-mail, and I'll send you some pix and dimensions.
I'm good in qrz.com
Phil
|
|
|
|
|
Logged
|
|
|
|
WB2WIK
Member
Posts: 20009
|
|
« Reply #4 on: August 08, 2008, 09:43:41 AM » |
|
$400 for a socket is not a bad deal at all. This is obviously a water-cooled tube with reservoir and circulator requirements for DI water, as well as enormous power resources required; I think the socket cost is probably the "smallest" investment associated with building such an amplifier!
|
|
|
|
|
Logged
|
|
|
|
AD4U
Member
Posts: 1918
|
|
« Reply #5 on: August 08, 2008, 10:55:10 AM » |
|
A 4CW10000 (Y442)amp may be difficult to "tame", because it will probably have to be operated in class AB. This is not a project for a first time amp builder.
If you want to build a big amp, a 3CX10000A7 or a 3CX15000A7 would be a better choice. It will operate in typical grounded grid configuration, and 1500 watts in should give 15,000 - 20,000 watts out.
CU on 20 meters.
.... ..
Dick AD4U
|
|
|
|
|
Logged
|
|
|
|
KD7YQM
Member
Posts: 71
|
|
« Reply #6 on: August 08, 2008, 11:03:39 AM » |
|
You are right on all counts Steve. I just thought I would try to determine the condition of the tube before investing in the spendy stuff. Since the tube only cost me $30 I didn't feel spending $400 on a socket just to test it. Well if that socket is such a good price people should be snapping them up. I don't see that.
Interestingly this tube is physically smaller than the 4-1000 albeit a whole lot heavier.
Funny I just wound me a transformer that is capable of 5kw. I thought it was way too large at 80 pounds. You probably couldn't get half power out of this tube with it. We'll see what I can do with it.
Dennis
|
|
|
|
|
Logged
|
|
|
|
KD7YQM
Member
Posts: 71
|
|
« Reply #7 on: August 08, 2008, 11:19:41 AM » |
|
Hi Dick
Yes I know this could be a difficult and costly endeavor.
I don't even know the condition of the tube yet. That was the whole purpose of this thread. The filament tests good with a ohm meter and nothing seems shorted. An emission test would tell the story though.
Being a tetrode I would say this would make a good grid driven amp operating AB1.
At this point I just want to try and get the filament lit.
Dennis
P.S. Anyone have any pics or schematics of this tube being used in an amp? Even a rf heating generator would be interesting to look at.
|
|
|
|
|
Logged
|
|
|
|
AD4U
Member
Posts: 1918
|
|
« Reply #8 on: August 08, 2008, 11:35:00 AM » |
|
Hi Dennis:
I am writing this with a sneaky grin on my face.
I have learned a little in my 40 years of hamming. One thing is when you go "horse racing" with the big boys with big amps, I don't care what you have, somebody will have a bigger one.
All this is posted in semi-jest, but in order to power such an amp, you would need at least a dedicated 240 volt 200 amp service. A suitable filament transformer may be hard to find, and you may have to wind one. The simplest plate transformer would be a reverse fed 25 KVA power company "pole pig".
Been there and done that.
Good Luck
Dick AD4U
|
|
|
|
|
Logged
|
|
|
|
KD7YQM
Member
Posts: 71
|
|
« Reply #9 on: August 08, 2008, 11:58:54 AM » |
|
I think you are right about the 25KVA pole pig Dick.
Absolute maximum ratings on this tube are 7500v at 3amps
That comes to 22500w
I think about 100amps at 240 should do it.
Boy that should dim some lights, huh?
I guess I don't have to run it at max but considering the 500w filament it would be nice to get a little more than that on output! ;>)
|
|
|
|
|
Logged
|
|
|
|
WB2WIK
Member
Posts: 20009
|
|
« Reply #10 on: August 08, 2008, 12:32:52 PM » |
|
>RE: Testing a 4CW10000(Y442) without socket??? Reply
by KD7YQM on August 8, 2008 Mail this to a friend!
Hi Dick
Yes I know this could be a difficult and costly endeavor.
I don't even know the condition of the tube yet. That was the whole purpose of this thread. The filament tests good with a ohm meter and nothing seems shorted. An emission test would tell the story though.<
::It will tell something, but not whether the tube is actually good unless you hipot test it or apply full rated plate voltage. I don't know how long you can dissipate any power before water cooling is required, but probably for "seconds" would be okay.
|
|
|
|
|
Logged
|
|
|
|
WA4ONV
Member
Posts: 51
|
|
« Reply #11 on: August 10, 2008, 07:08:57 AM » |
|
What ever happened to QRP ops...  lol Vy 73, Joe |
|
|
|
|
Logged
|
|
|
|
WA9SVD
Member
Posts: 2201
|
|
« Reply #12 on: August 12, 2008, 06:42:48 AM » |
|
To SOME people, that IS "QRP."
But has anyone (else) noticed the electric rates lately???
|
|
|
|
|
Logged
|
|
|
|
|
|
KD7YQM
Member
Posts: 71
|
|
« Reply #14 on: August 15, 2008, 03:10:41 PM » |
|
Thanks K6ELQ for that info.
|
|
|
|
|
Logged
|
|
|
|
|
