1watt p/ch 12au7x2

Cute! Here's its daddy. :-)

Tim

--
Deep Friar: a very philosophical monk.
Website: http://webpages.charter.net/dawill/tmoranwms

"ZACK`" wrote in message
...
1watt p/ch 12au7x2

"Tim Williams" wrote in message
...
Cute! Here's its daddy. :-)

Tim

--
Deep Friar: a very philosophical monk.
Website: http://webpages.charter.net/dawill/tmoranwms

"ZACK`" wrote in message
...
1watt p/ch 12au7x2







is that a 7/ch or 2/ch
how many watts

"ZACK`" wrote in message
u...
is that a 7/ch or 2/ch
how many watts

Monoblock, all 7 in PPP class AB, around 7W output.

Tim

--
Deep Friar: a very philosophical monk.
Website: http://webpages.charter.net/dawill/tmoranwms

http://cgi.ebay.com/LOT%2F2-RAYTHEON...20111004r23386

I'm having a "stupid moment": They are sold as pentodes, yet have
only 5 leads. What about the heaters? Well, the heater connections
must be exposed, else they wouldn't work, so what about the other
2 electrodes?


Martin - obviously missing something
--
M.A.Poyser Tel.: 07967 110890
Manchester, U.K. http://www.livejournal.com/userinfo.bml?user=fleetie

"Fleetie" ...
http://cgi.ebay.com/LOT%2F2-RAYTHEON...20111004r23386

I'm having a "stupid moment": They are sold as pentodes, yet have
only 5 leads. What about the heaters? Well, the heater connections
must be exposed, else they wouldn't work, so what about the other
2 electrodes?


Martin - obviously missing something

Battery stuff, directly heated, so the filament is also the cathode.
On a penthode G3 is almost always connected to the cathode.
Could be something like:

1 f
2 f + g3
3 g1
4 g2
5 anode

Arie de Muynck

On Sun, 04 Jan 2009 20:08:36 +0000, Fleetie wrote:

http://cgi.ebay.com/LOT%2F2-RAYTHEON...-PENTODE-TUBE-
PAIR-NIB_W0QQitemZ120352344397QQcmdZViewItemQQimsxZ2008 1220?
IMSfp=TL081220111004r23386

I'm having a "stupid moment": They are sold as pentodes, yet have only 5
leads. What about the heaters? Well, the heater connections must be
exposed, else they wouldn't work, so what about the other 2 electrodes?


Martin - obviously missing something

They are pentodes. http://www.radiomuseum.org/tubes/tube_ck5886.html

--
Mick (Working in a M$-free zone!)
Web: http://www.nascom.info
Filtering everything posted from googlegroups to kill spam.

On Sun, 4 Jan 2009 20:08:36 -0000, "Fleetie"
wrote:

http://cgi.ebay.com/LOT%2F2-RAYTHEON...20111004r23386

I'm having a "stupid moment": They are sold as pentodes, yet have
only 5 leads. What about the heaters? Well, the heater connections
must be exposed, else they wouldn't work, so what about the other
2 electrodes?


Martin - obviously missing something

Paste into browser...

tubedata.itchurch.org/sheets/127/5/5886.pdf

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

If we knew what we were doing, it wouldn't be called research...
-- Albert Einstein

On Sun, 04 Jan 2009 13:31:34 -0700, Jim Thompson
wrote:

On Sun, 4 Jan 2009 20:08:36 -0000, "Fleetie"
wrote:

http://cgi.ebay.com/LOT%2F2-RAYTHEON...20111004r23386

I'm having a "stupid moment": They are sold as pentodes, yet have
only 5 leads. What about the heaters? Well, the heater connections
must be exposed, else they wouldn't work, so what about the other
2 electrodes?


Martin - obviously missing something

Paste into browser...

tubedata.itchurch.org/sheets/127/5/5886.pdf

...Jim Thompson

Nominal grid current 3 fA.

John

On Sun, 04 Jan 2009 18:09:08 -0800, Archimedes' Lever
wrote:

On Sun, 04 Jan 2009 16:22:44 -0800, John Larkin
wrote:

On Sun, 04 Jan 2009 13:31:34 -0700, Jim Thompson
wrote:

On Sun, 4 Jan 2009 20:08:36 -0000, "Fleetie"
wrote:

http://cgi.ebay.com/LOT%2F2-RAYTHEON...20111004r23386

I'm having a "stupid moment": They are sold as pentodes, yet have
only 5 leads. What about the heaters? Well, the heater connections
must be exposed, else they wouldn't work, so what about the other
2 electrodes?


Martin - obviously missing something

Paste into browser...

tubedata.itchurch.org/sheets/127/5/5886.pdf

...Jim Thompson

Nominal grid current 3 fA.

John


Extrapolated.

Extrapolated from what? No, I'm sure this was measured.


I have seen and used a picoammeter. I have never seen a femtoammeter.

It's easy to measure fet gate or tube grid current, into the attoamps,
thousands of electrons per second. The first time I got my hands on
some RCA small-signal mosfets, I was astounded at the pA gate
currents.

Just make a follower and connect its input to a low-leakage capacitor,
an air cap in the extreme. Short the cap, open it, and monitor the
source or cathode with a DVM. Watch the voltage change with time. Do
the math. Easy.

John

On Sun, 04 Jan 2009 20:58:39 -0800, Archimedes' Lever
wrote:

On Sun, 04 Jan 2009 18:52:14 -0800, John Larkin
wrote:

On Sun, 04 Jan 2009 18:09:08 -0800, Archimedes' Lever
wrote:

On Sun, 04 Jan 2009 16:22:44 -0800, John Larkin
wrote:

On Sun, 04 Jan 2009 13:31:34 -0700, Jim Thompson
wrote:

On Sun, 4 Jan 2009 20:08:36 -0000, "Fleetie"
wrote:

http://cgi.ebay.com/LOT%2F2-RAYTHEON...20111004r23386

I'm having a "stupid moment": They are sold as pentodes, yet have
only 5 leads. What about the heaters? Well, the heater connections
must be exposed, else they wouldn't work, so what about the other
2 electrodes?


Martin - obviously missing something

Paste into browser...

tubedata.itchurch.org/sheets/127/5/5886.pdf

...Jim Thompson

Nominal grid current 3 fA.

John


Extrapolated.

Extrapolated from what? No, I'm sure this was measured.


I have seen and used a picoammeter. I have never seen a femtoammeter.

It's easy to measure fet gate or tube grid current, into the attoamps,
thousands of electrons per second. The first time I got my hands on
some RCA small-signal mosfets, I was astounded at the pA gate
currents.

Just make a follower and connect its input to a low-leakage capacitor,
an air cap in the extreme. Short the cap, open it, and monitor the
source or cathode with a DVM. Watch the voltage change with time. Do
the math. Easy.

John


In other words... extrapolated. You take a measure of a voltage,and
calculate (read extrapolate) the amperage.

That's measured, not extrapolated. How do you think your picoammeter
works? Does it count electrons passing?

Calculate is not the same as extrapolate:

http://en.wikipedia.org/wiki/Extrapolate

"In mathematics, extrapolation is the process of constructing new data
points outside a discrete set of known data points."


You make a positive effort to be Always Wrong.

John

Thanks, guys!


Martin
--
M.A.Poyser Tel.: 07967 110890
Manchester, U.K. http://www.livejournal.com/userinfo.bml?user=fleetie