6M5 datasheet
Alex
6M5 output tube was common in some radios. I have read that 6M5 was similar
to EL84, but have never seen its real datasheet.
Could anybody on this forum please post me a link to an original 6M5
datasheet?
Thanks and regards,
Alex
Patrick Turner
Before asking here, most people enter '6M5 tube data ' into Google, or
any other tube number
or transistor number.
See Duncan's TDSL pages with lots of links.
The 6M5 is indeed like 6BQ5/EL84, but not as good imho, and I often
change the socket connections
of radios from 6M5 to suit 6BQ5 because the 6M5 is no longer made and
the 6BQ5
is very plentiful.
Patrick Turner.
Steve H
Steve H
Bob L.
--
Bob L.
Lindenhurst, NY
"Patrick Turner" <in...@turneraudio.com.au> wrote in message
news:476BC247...@turneraudio.com.au...
robert casey
>
> Can find datasheets here
>
> http://www.mif.pg.gda.pl/homepages/frank/vs.html
It shows up here:
http://www.mif.pg.gda.pl/homepages/frank/short/054/2/215.pdf
It says that it's the same as EL80
=========================================================================
What did Santa Claus say at the house of ill repute?
"Ho ho ho!"
Alex
closest equivalent is EL80, but how can I be sure?
"robert casey" <wa2...@ix.netcom.com> wrote in message
news:13mo9c6...@corp.supernews.com...
Alex
> any other tube number
> or transistor number.
> See Duncan's TDSL pages with lots of links.
>
> The 6M5 is indeed like 6BQ5/EL84, but not as good imho, and I often
> change the socket connections
> of radios from 6M5 to suit 6BQ5 because the 6M5 is no longer made and
> the 6BQ5
> is very plentiful.
>
> Patrick Turner.
I typed "6M5 data" in Google, but could never get a genuine 6M5 datasheet
scan.
Some say it is like EL84, others say it is like EL80. However, EL84 and EL80
are not identical. Though both have rather high transconductance, EL80
according to its datasheet runs at 33mA (as 6F6) and would require higher
plate load impedance, than EL84 which runs at 45...48mA (as 6V6).
That is why I brought the question up at this forum, hoping that some guru
would have reliable information on hand.
Regards,
Alex
Engineer
> my references mention it. The only thing I can think of with a '6' and
> an 'M' in it that vaguely meets your description would be a 6CM6.
>
> That's a 9 pin 6V6 but it's not an EL84 equivalent despite being an
> audio power amp with 12 Watt plate.
Never thought I'd see a reference to a 6CM6! It's the O/P tube used in
the Stromberg-Carlson AR-411 tube amplifier - I restored one earlier
this year. I managed to buy a few spares from a very helpful chap in
the US. I get the feeling that they are not as common as 6AQ5's or
octal 6V6's. Before I found replacements I was contemplating making a
base adapter (9 pin to 7 pin) and using a couple of 6AQ5's (rebiased),
then my USA friend rescued me!
Cheers, and a Merry Christmas to all Vacuumlanders!
Roger
PS. To Alex - I've never heard of a 6M5, either.
hor...@iinet.net.au
Hi, The 6M5 Tube = European EL80 was derived from the 8 pin Rimlock
Socket EL41 or 6CK5
It is in no way the same as the 6BQ5/EL86. The socket connections are
different, and mainly, the 6M5 has a load resistance of 7000 Ohm
where the 6BQ5 has 5000 ohms.
The 6M5 was used in quite a few Australian Radios, In Kriesler, HMV ,
Astor and many more.
It really had no equivalent in a 9 pin socket. The closest to it is
the 6GW8/ECL86 pentode part. The characteristics and voltages are very
similar.So is the load resistance of 7000 Ohms. The Filament current
is also nearly the same.
This means, the same output transformer can be used
This tube was made in Australia by Philips, Mullard and AWV (RCA).
Also in the US a few companies manufactured it.
it was not popular in europe. The manufacturres most of the time went
straigt from the EL41 to the EL84, which was then the most used single
ended output tubes in radios.
The Pin connections are:
Pin 1=g2, Pin 2=g1, Pin 3=k+g3, Pin4,5 = Heater , pin 6=IC, Pin
7=a,
Pin 8=IC and Pin 9=NC.
The 6M5s had a bit of a problem, they tended to draw grid current when
they started to get old. I had 2 radios today, where the grid was
about 4V positive .
The cathode voltage went up to about 11Volts and the tube took a lot
more anode current. It also got very hot.
It is not a very nice looking tube, specially when used for a long
time.
The inside goes black and outside the anode inspection holes, a silver
layer builds up. The same applied to the EL41.
I hope this helps a bit.
If you need more info , Data , history etc, please let me know.
Regards, Horst
John Byrns
<8a0aeca1-dab2-4792...@s12g2000prg.googlegroups.com>,
hor...@iinet.net.au wrote:
> The 6M5s had a bit of a problem, they tended to draw grid current when
> they started to get old. I had 2 radios today, where the grid was
> about 4V positive .
What does "draw grid current" mean? Does this mean positive or negative
grid current? I guess we should be able to devine the answer from the
statement that the grid is 4 volts positive.
Regards,
John Byrns
--
Surf my web pages at, http://fmamradios.com/
Alex
>
> - Show quoted text -
Thanks, Horst.
Your reply was quite comrehensive. I need to restore a PHILIPS radio
with 6M5. The 6M5 is all dark and silvery from inside the bulb,
indicating that it is most likely dead. I would probably use EL84, but
now I need to be careful not to use EL84 in a standard mode with 48mA
anode current in order not to saturate the transformer. What would you
recommend:
- artificially reduce anode current in EL84 by biasing it more than
typical;
- reduce Ug2 to EL84 to 180V;
- find another substitution valve with typical 33...36mA at Ug2=250V;
- something else??
Regards,
Alex
hor...@iinet.net.au
> > straight from the EL41 to the EL84, which was then the most used single
Hi Alex, Before you discard your 6M5 as bad, do a couple of tests.
You need a High impedance meter, Either a digital voltmeter or a
VTVM..
1st disconnect the coupling capacitor from the grid of the 6M5. Read
the voltage from the grid to ground. you should have zero volts, if
your radio uses a cathode resistor on the 6M5 cathode . If it uses
semiautomatic bias, then you should have about -6 or similar on the
grid. The main thing, you should not have a positive voltage at all.
If it is positive your tube is crook.
2nd. If it is zero volts, measure the cathode voltage. this should be
about 6 to 7 volts. If it is less, then the valve is weak.
If it is ok, replace your coupling condenser and fit a new one.
If it is faulty, the closest (just about completely identical) tune is
the 6GW8/ECL86.
No component values need to be altered including the cathode resistor.
both have 170Ohm and both tubes draw 36mA anode current. The Gm on
both is 10mA/V
It is easy to rewire the socket. Do it in the following sequence
1.) Move the wire from pin 7 to pin 6 (a)
2.) Move the wire from pin 1 to pin 7 (g2)
3.) Exchange the wires from pin 2 and pin 3 (cg3 and g1)
Pins 1,8 and 9 should have no connections. Short pin 9 to ground.(at)
This will give you identical results .
If you don't have a 6GW8, then I am happy to send you a new one at no
cost.
The 6GW8 is really a very good reliable tube. the triode section is
identical to half a 12AX7/ECC83.
The tube started to come in to use in big style in the early 60's. It
was used a lot in the Japanese amplifiers. (Pioneer , Sansui, Trio
etc) . Mostly in push pull in this Tuner-Amps. It got a reasonably bad
reputation then, because the Japanese, to get the power ratings up,
used it to the limits. It just got to hot and died from shorted grid
and from open cathodes.
I replaced plenty. During this time I worked at Astor Radio in the
service dept.
Astor being part of EIL. Did all the Pioneer repairs, and during this
time i did them all. (EIL was the Australian importer of pioneer).
When the tube was used within its ratings, it performed for a very
long time without problems.
Let me know, if you need one, and let me have your mailing address.
My email is: hor...@iinet.net.au
Happy Christmas, Horst
Alex
>
> - Show quoted text -
Thanks, Horst.
I appreciate your thorough advice very much. It sounds you have had a
lot of experience.
Merry Christmas and a happy New Year.
Regards,
Alex