gibert cell in glass?
 

Hi,

Has anyone ever implemented a gilbert cell mixer using valves instead
of FETs?
I'm considering this instead of using the increasingly rare and costly
heptode mixer.

Thanks,

The Eternal Squire
(yes, I have a call, I just like my privacy)

"The Eternal Squire" wrote in message
om...
Hi,

Has anyone ever implemented a gilbert cell mixer using valves instead
of FETs?
I'm considering this instead of using the increasingly rare and costly
heptode mixer.

There was some sort of dual tetrode (6164?) that used to be used in high
performance mixers for valve radios.

Leon

"The Eternal Squire" wrote in message
om...
Hi,

Has anyone ever implemented a gilbert cell mixer using valves instead
of FETs?
I'm considering this instead of using the increasingly rare and costly
heptode mixer.

There was some sort of dual tetrode (6164?) that used to be used in high
performance mixers for valve radios.

Leon

6U8 or 6X8 are a dime a dozen and great mixers. Also 6BL8, 6EA8 are good
up to 220MHz. 6J6 goes to 600MHz.

I have tried to develop "glass Gilberts", but tubes are too linear.

--
Gregg
*It's probably useful, even if it can't be SPICE'd*
http://geek.scorpiorising.ca

6U8 or 6X8 are a dime a dozen and great mixers. Also 6BL8, 6EA8 are good
up to 220MHz. 6J6 goes to 600MHz.

I have tried to develop "glass Gilberts", but tubes are too linear.

--
Gregg
*It's probably useful, even if it can't be SPICE'd*
http://geek.scorpiorising.ca

the greatest valve mixer ever was based on 7360. a dual beam tetrode
specifically meant for being a high dynamic range mixer.

you can also try making a commutation mixer with four triodes.

- farhan

the greatest valve mixer ever was based on 7360. a dual beam tetrode
specifically meant for being a high dynamic range mixer.

you can also try making a commutation mixer with four triodes.

- farhan

Behold, Ashhar Farhan signalled from keyed 4-1000A filament:

the greatest valve mixer ever was based on 7360.

snip

How true!!

--
Gregg
*It's probably useful, even if it can't be SPICE'd*
http://geek.scorpiorising.ca

Behold, Ashhar Farhan signalled from keyed 4-1000A filament:

the greatest valve mixer ever was based on 7360.

snip

How true!!

--
Gregg
*It's probably useful, even if it can't be SPICE'd*
http://geek.scorpiorising.ca

In article ,
(The Eternal Squire) writes:

Has anyone ever implemented a gilbert cell mixer using valves instead
of FETs?
I'm considering this instead of using the increasingly rare and costly
heptode mixer.

To do this, one needs a minimum of three triodes, the top pair
being (essentially) a differential amplifier, the bottom being a
configured constant-current source replacing a moderately-
high common cathode resistor for the differential pair.

That's a LOT of circuit work where a single dual triode could
(and has) work just as well. Connect it as a differential pair
and put the signal in one side, the LO in the other.

Any valve that runs its control grid into the positive region is
going to be operating in a non-linear region and will therefore
"mix" well enough to do some heterodyning.

The name "Gilbert cell" got there in later integrated circuit
times to describe a particular arrangement of BJT junctions
to do mixing or AGC actions. Valve circuitry had other
names and worked for decades as mixers quite will without
fancy names. :-)