|Author:||automap68 (registered user: 127 posts )|
|Date:||Sun, Feb 05th, 2012 @ 16:29 ( . )|
On 02/05/2012 @ 16:13, MadDog wrote :
Also, there is a voltage drop of about 35 volts or so from the anode to cathode.
: The plate is really only getting about 319 volts
: We're having a little problem with terminology. Plate voltage is the DC voltage you measure from plate to cathode. Perhaps 319 is the B+ (designated B+1 on the SEL schematic)? If so, please measure volts across C1, too.
: Where are you seeing 35 volts? Really from plate (aka 'anode' across the pond) to cathode? We have to make sure we are talking about the same thing before we can help.
: While you're taking measurements, what is your screen voltage? (this is the DC voltage measured from the screen grid to the cathode)
: Also, that's the Heybouer OT in the picture isn't it? What taps did you end up using?
: How do you know it's only putting out 4 Watts? How did you measure output power?
: 27.5 volts is 3 volts less than nominal, but your B+ is low, too (if 319 is your B+) so I'd expect cathode voltage to be low -- hardly 'paperweight' time.
The 4 watt measurement came from an acutally load meter.
Simulates a speaker.
Set the impedance and the multiplier and let her rip.
Very nice toy to have
So actualy it was barley 4 watts we saw mostly 2
yes that is a hayboer o/t
used the 2.5k tap
the 6k made it real bad and the 4k was no improvment
I checked the o/t with a 2.5 k resistor so simulate the tube and i get a nice 7.7 ohms on the 8 ohm tap so the o/t seems normal
the amp was being powered on a variac so i was able to test it both nice and low at 100 volts and also at 120
yes sorry about terminology
b+ was 319ish but that was also at 100 volts testing so at 120 it was higher i forget what it is.
I had to leave my mentors shop so im home on my own bench and dont have all the awesome stuff. I have a scope and signal gen and so on but not the really nice crap he has
the 30 volts was i believe on the cathode.
But just to be sure.
Maddog if you could reply with exactly the measurrments you would like me to return including test locations
i can give you some better results that may make more sense so u can help
I normally study fields and do math all day so my tube terminology is not up to par but im getting there slowly
--* SEL DONE layout check and pics please
2/07/2012 @ 14:18--spud
2/11/2012 @ 20:49--joe kerr
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