Vacuum Tube teardown - the ECH81 signal mixer tube

[@Hellhound604]

Brings back good memories of my school-days in the 1970’s, stripping all sorts of vacuum tubes to see what the look inside.

[@IndianArmy-li2fw]

Excellent

[@krystianrak5891]

Hi,Do you know if it should be caught on the radio Saba wildband 125? because I don't shine and it's cold

[@seetaramhegde4777]

Good

[@samklazar8995]

My tube radio is not picking MW stations but SW stations. Is resistance connected in Pin no 7 &9 (33k) to ground is responsible?

[@Cien_Swiatla]

witam serdecznie, bardzo fajny material.

[@FesZElectronics]

Dziękuję Ci!

[@josquinmingus]

Very helpful! I'm trying to understand how the triode side works with the oscillator. What comes out of and/or goes into the triode's grid (7 & 9) and plate (8)? The radio I'm learning on uses a dual triode (7F8) instead of a heptode+triode, and I'm not clear on the paths on the right side. Thank you, and remember to floss :-)

[@FesZElectronics]

Well the oscillator is basically an Armstrong type only difference being that the resonant circuit is in the anode rather than on the grid. I'm not entirely sure why they connected the triode grid with with the heptode grid. I guess this way there is better separation between the local oscillator (that is only in the anode of the triode) and the mixing heptode.

[@perpersson5562]

what is the purpuse of this tube?

[@fakharvoice9215]

thank u v.much......................... love 4rm Pakistan

[@FesZElectronics]

I am happy you liked it! It's good to know people still care about the old vacuum tubes

[@soroushma7249]

hi , i really need this model radio's circuit : Weimar Super 87/55W201 can u help me?

[@FesZElectronics]

Hello there! well I do not have that schematic unfortunately, but I managed to find a similar one online - www.freibergschubis.de/stefan/nostalgie/pictures/erfurt4schem.jpg ; this radio is made by the same company and has the same ECH-EBF-EBF AM radio part.. maybe it helps; I will keep looking though, and let you know if I find anything usefull

[@DoctorMangler]

LOLOLOL HAHAHA Thank you so much for trying at least HAHAHAHAHA!

[@DoctorMangler]

I'm so sorry for such a late watching of your video, I've been stuck down in a boiler room for days, I'm laughing so hard I can't see anymore.

[@FesZElectronics]

I'm always open to new suggestions :D bone is actually a very good material to make tools out of, it has been widely used in prehistory; there might just be a place for it in modern electronics too!

[@FesZElectronics]

May I ask how you got stuck in a boiler room?

[@DoctorMangler]

@@FesZElectronics I'm a plumber and we service small steam boilers and general plumbing in old apartment buildings. We've had back to back emergency repair work for about 2 weeks now. :P 12 hour days = no youtube for me.

[@FesZElectronics]

I understand... but I guess that you get to see all sort of weird and interesting old equipment and things in boiler rooms. People store away the strangest things, and end up forgetting about them for many years.

[@nasalimbu3078]

Hecate Hestia

[@zsomborherceg493]

Magyar vagy?

[@petzi8695]

Desfa un em84

[@FesZElectronics]

As dori sa trec prin toate tuburile dintr-un radio Carmen 3 prima oara, deci voi desface un ochi magic EM80, dar dupa aceea voi ajunge si la un EM84