Gentlemen,

here is another sleeper: EL86 aka 6CW5 and PL84 (no typo!)
aka 15CW5 for the 300mA DC heater version.

http://www.ndh.net/home/schlangen/ro..._as_triode.pdf

Compared to trioded ECL82 pentode section, you get even
lower rp, more gain and considerably better linearity.

Data was derived from 3 NOS/NIB samples: TFK EL86, Motorola 6CW5
and TFK PL84.

EL86 and PL84 is cheap as dirt over here in Germany, if
you know how were to find them :-)

Enjoy,

Tom

--
Knowledge is power - knowledge shared is power lost.

Tom Schlangen wrote:

Gentlemen,

here is another sleeper: EL86 aka 6CW5 and PL84 (no typo!)
aka 15CW5 for the 300mA DC heater version.

http://www.ndh.net/home/schlangen/ro..._as_triode.pdf

Compared to trioded ECL82 pentode section, you get even
lower rp, more gain and considerably better linearity.

Data was derived from 3 NOS/NIB samples: TFK EL86, Motorola 6CW5
and TFK PL84.

EL86 and PL84 is cheap as dirt over here in Germany, if
you know how were to find them :-)

EL86 has about half the gain as EL84, but half the Ra.

EL84 in triode is like 5 halves of a 6SN7 strapped in parallel,

EL86 in triode is like 4 halves of 12BH7 ditto.

I like both for drive amp purposes.

The quoted Ra of 1,000 ohms is in a middle range, and depending on
Ia, the Ra varies considerably, as do all triodes.

Thanks for the data.

Patrick Turner.



Enjoy,

Tom

--
Knowledge is power - knowledge shared is power lost.

Hi Patrick,

The quoted Ra of 1,000 ohms is in a middle range,
and depending on Ia, the Ra varies considerably,
as do all triodes.

Of course. But with the curves, everyone can derive
mu, gm and rp now for a chosen op point :-)

Thanks for the data.

Glad I can give a bit back to the group.

Before ripping the measuring rig apart, I'll
run a few other candidates through it, like
trioded 6V6, EL38/6CN6 and maybe EL36.

Tom

--
A gleekzorp without a tornpee is like
a quap without a fertsneet (sort of).

Hi Tom ,

Looks like a nice beefy low B+ triode !!

Before ripping the measuring rig apart, I'll
run a few other candidates through it, like
trioded 6V6, EL38/6CN6 and maybe EL36.

Poor Ines ;-))
Does she get payed by you doing the dishes ?? :P

Ronald .

any chance you have a few ECL84?
got a box here that I am playing with.

Doug


"Tom Schlangen" wrote in message
...
Hi Patrick,

The quoted Ra of 1,000 ohms is in a middle range,
and depending on Ia, the Ra varies considerably,
as do all triodes.

Of course. But with the curves, everyone can derive
mu, gm and rp now for a chosen op point :-)

Thanks for the data.

Glad I can give a bit back to the group.

Before ripping the measuring rig apart, I'll
run a few other candidates through it, like
trioded 6V6, EL38/6CN6 and maybe EL36.

Tom

--
A gleekzorp without a tornpee is like
a quap without a fertsneet (sort of).

Tom Schlangen wrote:

Hi Patrick,

The quoted Ra of 1,000 ohms is in a middle range,
and depending on Ia, the Ra varies considerably,
as do all triodes.

Of course. But with the curves, everyone can derive
mu, gm and rp now for a chosen op point :-)

Thanks for the data.

Glad I can give a bit back to the group.

Before ripping the measuring rig apart, I'll
run a few other candidates through it, like
trioded 6V6, EL38/6CN6 and maybe EL36.

You may as well do EL34 KT88 6550 while your at it.

What about 6EJ7, EF86, and other small pentodes, 6AU6.

Did I just wreck your next 3 sundays?

Patrick Turner.



Tom

--
A gleekzorp without a tornpee is like
a quap without a fertsneet (sort of).

Hi Patrick,

You may as well do EL34 KT88 6550 while your at it.

Well, those (and many other triode strapped power pentodes)
are covered for me by Mr. Broskies SE CAD, which has an
integrated fancy graphing function.

Especially regarding KT88/6550, there is lots of
additional interesting data available on the 'net
from some Australian dude at:

http://www.turneraudio.com.au/htmlwe...50pographs.htm

Maybe you have some additional graphs to share ;-)

What about 6EJ7, EF86, and other small pentodes, 6AU6.

6EJ7/EF184 would be interesting, indeed (noted)

EF86 is covered (look at page 11) by:

http://frank.pocnet.net/sheets/030/e/EF86.pdf

6AU6/EF94 is also covered (look at last page):

http://frank.pocnet.net/sheets/020/6/6AU6.pdf

Did I just wreck your next 3 sundays?

Hardly :-)

Tom

--
Okay, maybe i am paranoid. But that doesn't mean
they are not out to get me. - unknown

Hi Doug,

any chance you have a few ECL84?

Sorry to say so, but no.

Tom

--
A gleekzorp without a tornpee is like
a quap without a fertsneet (sort of).

Hi Ronald,

Poor Ines ;-))

Naaa. The data digging is optimized now (at least
for the smaller tubes) by pre-checking/selecting
the samples on similar operation at a few op points
and then strapping them in parallel, which makes
for an averaging function...

Tom

--
Okay, maybe i am paranoid. But that doesn't mean
they are not out to get me. - unknown

Tom Schlangen wrote:

Hi Patrick,

You may as well do EL34 KT88 6550 while your at it.

Well, those (and many other triode strapped power pentodes)
are covered for me by Mr. Broskies SE CAD, which has an
integrated fancy graphing function.

Especially regarding KT88/6550, there is lots of
additional interesting data available on the 'net
from some Australian dude at:

http://www.turneraudio.com.au/htmlwe...50pographs.htm

Maybe you have some additional graphs to share ;-)

Who is this dude? some crazy Oz tube fanatic.....

Not sure I have too many more triode graphs...



What about 6EJ7, EF86, and other small pentodes, 6AU6.

6EJ7/EF184 would be interesting, indeed (noted)


E280F is the best of the family....


EF86 is covered (look at page 11) by:

http://frank.pocnet.net/sheets/030/e/EF86.pdf

6AU6/EF94 is also covered (look at last page):

http://frank.pocnet.net/sheets/020/6/6AU6.pdf

Did I just wreck your next 3 sundays?

Hardly :-)


I'm going out to play chess, so the last bit of sunday
may be sorowful, since I sure can't winem all.

Patrick Turner.


Tom

--
Okay, maybe i am paranoid. But that doesn't mean
they are not out to get me. - unknown

[kegger]

Hey what a great service you are doing here.

I am wondering if you did ever get a chance to do any 6EJ7 or 6EH7 data sheets?
I'm really curious about the plate resistance and gain on these strapped in triode.

I have several of these tubes and was thinking of triode strapping them as drivers.
Thanks for anything anyone may want to share on these particular tubes.

[Patrick Turner]

kegger wrote:

Hey what a great service you are doing here.

I am wondering if you did ever get a chance to do any 6EJ7 or 6EH7 data
sheets?
I'm really curious about the plate resistance and gain on these
strapped in triode.

6EH7 is a variable gain pentode which has its gm controlled by the
dc bias to g1.
Its not really suitable for use in linear audio circuits unless you like
much larger than normal 2H.

6EJ7 is a sharp cut off pentode, frame grid also,
and high gm of 12mA/V and Ra of 350k at 10mA in pentode, so µ is a very
high 3,500.
So if you had a load = 350k from an active current source you'd get a
gain of 1,750
without NFB loops.

When strapped as a triode you have µ = 60, Ra = 12k at 5mA for Ia.
It makes a very good triode about equal to a 12AT7 with both halves in
parallel.

Data curve sheets for the 6EH7 and 6EJ7 are easily available on the web
for pentode,
but not for triode, but
The 6EJ7 in triode is ideally set up with Ia = 5mA, RL = 33k, Ea = 120V,
supply = 285V,
and gain is about 44. Maybe you'd get 50Vrms at about 2% thd, mainly 2H.
Using a µ follower with a second 6EJ7 as the top tube, with
Rk between top cathode and bottom tube anode = 5k gives a dynamic
load for the bottom tube of over 300k, and the Dn
will drop from 2% at 50Vrms to probably about 0.6%.
Expect 0.01% thd at 1 Vrms.

It won't be as linear as a 6SN7/6CG7 or EL86 in triode.
But two will make a good LTP, and at low Vout the 2H cancels
and at say 5Vrms from each anode load of say 33k,
expect THD much less than single ended case; its so low
you just don't need to worry about it.
Same goes for 6SN7 and EL86 and also EL84 in LTPs,
and I have had 0.1% THD at 70Vrms at each anode with a pair of EL84
with each anode load = 22k, Ia = 14mA, Ea = 240V.
See the driver stage in the schematic at
http://www.turneraudio.com.au/8585-a...ober-2006.html

Patrick Turner.






I have several of these tubes and was thinking of triode strapping them
as drivers.
Thanks for anything anyone may want to share on these particular tubes.

--
kegger

[Tom Schlangen]

Hi Patrick,

Data curve sheets for the 6EH7 and 6EJ7 are easily
available on the web for pentode, but not for triode,

6EJ7 trioded is available at my website and I am quite
sure I even sent it to you by Email two years ago, or
something ;-)

Here's the link to my "as triode" collection:

http://www.tubes.mynetcologne.de/roe..._triode_e.html

Tom

--
MS-DOS is the worst text adventure game I have ever played:
Poor vocabulary, weak parser and boring storyline.

[kegger]

Thanks a lot, both of you.

As it turns out I may use the 6CW5/EL86 for the driver I was looking for.

I was looking for a 9 pin triode that was less then 5k plate resistance and less then say 10mu.
I'm currently running 12B4's in that spot and was looking for an alternitive to try with low gain.

Figured some of these not so used pentodes may turn out to be decent triodes.

Again, thanks a bunch.

[Patrick Turner]

Tom Schlangen wrote:

Hi Patrick,

Data curve sheets for the 6EH7 and 6EJ7 are easily
available on the web for pentode, but not for triode,

6EJ7 trioded is available at my website and I am quite
sure I even sent it to you by Email two years ago, or
something ;-)

Here's the link to my "as triode" collection:

http://www.tubes.mynetcologne.de/roe..._triode_e.html

Tom

Indeed you are right Tom, and I forgot that I got the triode data
from you, like most others.
But apart from your source, there ain't much on many trioded pentodes.
And I have moved to another newer pc and something is wrong with the
floppy
so I cannot get the files of my audio tech folders from
the old PC to the newer one yet.
So I couldn't send the poster a copy of the EH7 triode data.

But now he knows where it is.

Patrick Turner.


--
MS-DOS is the worst text adventure game I have ever played:
Poor vocabulary, weak parser and boring storyline.