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


the greatest valve mixer ever was based on 7360.


snip

How true!!

There were also some tv tubes used in chroma demodulators
that were sorta 7360 ish. The 6AR8 for one, I know there
were a few others.

BTW you had to use mu-metal shields on these for best
results.

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

Farhan,

I saw your post re nukes on my personal account new server but can't
post out, and I don't see your post on Google yet. I hope you don't
mind my answering your second message here.

I understand what you mean about the India/Pakistan conflict. I
really don't know what to say. Yes, it is a grim business. But I'm
thinking about the kind of world my daughter will inherit, and I want
her to be equipped for it.

I think that an attack meant to wipe out a country will simply not
happen, thank gawd, because the balance of terror still exists today
and that balance works just fine. Thats why India and Pakistan came
to thier senses, and that's why the US and USSR shadow-boxed each
other without doing anything serious.

The only likely scenarios I see are two-fold:

1) Terrorist sneaks in by motor boat or rogue sub to the seashore,
walks into a major city with a 50 kilotonne warhead in a backpack and
ignites it kamikaze style. The city is wiped, the suburbs are
fried, and the farm and ranch country gets hit with the EMP. It's the
people in the farm and ranch country that would be in the best shape
to use my design and coordinate with FEMA
about how to handle the survivors and the damage.

2) In response to our conventional defense of Taiwan when China
inevitably loses patience and invades, China fires a single large
coldbringer warhead in the ionosphere above the center of the
continental US. The purpose of a coldbringer is not to ruin a city,
although it still might very well do so. It is to generate a large
EMP across the country to ruin a country's ability to communicate or
compute, thereby ruining thier economy and ability to mobilize
anything larger than a single army or marine division for some period
of years.

It is most likely the unwritten policy within members of UN Security
Council that a massive retalitation will never be made in response to
the detonation of a single warhead. China would likely say: "oops,
so sorry, it was an accident, some general had an itchy trigger
finger. We'll execute him and make reparations.". Plausible
deniability. In the meantime, our country is powerless to defend
Taiwan because while our teeth might be there, our supply lines still
originate in the US. China then conquers Taiwan with ease.

In a scenario like this, the entire country will be physically
unharmed but will be in chaos, needing operators with equipment not
damaged by EMP. I'd like my daughter to be able to help out if she
can.

That's all I have to say for tonight.

The Eternal Squire

The Eternal Squire wrote:
2) In response to our conventional defense of Taiwan when China
inevitably loses patience and invades, China fires a single large
coldbringer warhead in the ionosphere above the center of the
continental US. The purpose of a coldbringer is not to ruin a city,
although it still might very well do so. It is to generate a large
EMP across the country to ruin a country's ability to communicate or
compute, thereby ruining thier economy and ability to mobilize
anything larger than a single army or marine division for some period
of years.

It is most likely the unwritten policy within members of UN Security
Council that a massive retalitation will never be made in response to
the detonation of a single warhead. China would likely say: "oops,
so sorry, it was an accident, some general had an itchy trigger
finger. We'll execute him and make reparations.". Plausible
deniability. In the meantime, our country is powerless to defend
Taiwan because while our teeth might be there, our supply lines still
originate in the US. China then conquers Taiwan with ease.

In a scenario like this, the entire country will be physically
unharmed but will be in chaos, needing operators with equipment not
damaged by EMP. I'd like my daughter to be able to help out if she
can.

That's all I have to say for tonight.

The Eternal Squire
I think if this happened we just might also have an 'oops' and a single
thermo nuke would go off high in the atmosphere above China. "There,
we're even." (This isn't a "massive retalitation", so it's allowed under
UN policy). Now both sides can blindly stumble about in Taiwan.

I found something that I *think* comes close to what I want, but
I am not sure. Look at Figure 7 on the bottom of:

http://laplaza.org/~fvuotto/mustage.html

Assuming I had the correct values for R's and C's for broadband
RF operation, it looks as though I could put VFO on one input and
RF on the other input, getting IF's about 90 degrees apart for
use in IQ demodulation.

Do you all read the same thing that I do?

Thanks,

The Eternal Squire

I found something that I *think* comes close to what I want, but
I am not sure. Look at Figure 7 on the bottom of:

http://laplaza.org/~fvuotto/mustage.html

Assuming I had the correct values for R's and C's for broadband
RF operation, it looks as though I could put VFO on one input and
RF on the other input, getting IF's about 90 degrees apart for
use in IQ demodulation.

Do you all read the same thing that I do?

Thanks,

The Eternal Squire

The Eternal Squire wrote:
2) In response to our conventional defense of Taiwan when China
inevitably loses patience and invades, China fires a single large
coldbringer warhead in the ionosphere above the center of the
continental US. The purpose of a coldbringer is not to ruin a city,
although it still might very well do so. It is to generate a large
EMP across the country to ruin a country's ability to communicate or
compute, thereby ruining thier economy and ability to mobilize
anything larger than a single army or marine division for some period
of years.

It is most likely the unwritten policy within members of UN Security
Council that a massive retalitation will never be made in response to
the detonation of a single warhead. China would likely say: "oops,
so sorry, it was an accident, some general had an itchy trigger
finger. We'll execute him and make reparations.". Plausible
deniability. In the meantime, our country is powerless to defend
Taiwan because while our teeth might be there, our supply lines still
originate in the US. China then conquers Taiwan with ease.

In a scenario like this, the entire country will be physically
unharmed but will be in chaos, needing operators with equipment not
damaged by EMP. I'd like my daughter to be able to help out if she
can.

That's all I have to say for tonight.

The Eternal Squire
I think if this happened we just might also have an 'oops' and a single
thermo nuke would go off high in the atmosphere above China. "There,
we're even." (This isn't a "massive retalitation", so it's allowed under
UN policy). Now both sides can blindly stumble about in Taiwan.

Farhan,

I saw your post re nukes on my personal account new server but can't
post out, and I don't see your post on Google yet. I hope you don't
mind my answering your second message here.

I understand what you mean about the India/Pakistan conflict. I
really don't know what to say. Yes, it is a grim business. But I'm
thinking about the kind of world my daughter will inherit, and I want
her to be equipped for it.

I think that an attack meant to wipe out a country will simply not
happen, thank gawd, because the balance of terror still exists today
and that balance works just fine. Thats why India and Pakistan came
to thier senses, and that's why the US and USSR shadow-boxed each
other without doing anything serious.

The only likely scenarios I see are two-fold:

1) Terrorist sneaks in by motor boat or rogue sub to the seashore,
walks into a major city with a 50 kilotonne warhead in a backpack and
ignites it kamikaze style. The city is wiped, the suburbs are
fried, and the farm and ranch country gets hit with the EMP. It's the
people in the farm and ranch country that would be in the best shape
to use my design and coordinate with FEMA
about how to handle the survivors and the damage.

2) In response to our conventional defense of Taiwan when China
inevitably loses patience and invades, China fires a single large
coldbringer warhead in the ionosphere above the center of the
continental US. The purpose of a coldbringer is not to ruin a city,
although it still might very well do so. It is to generate a large
EMP across the country to ruin a country's ability to communicate or
compute, thereby ruining thier economy and ability to mobilize
anything larger than a single army or marine division for some period
of years.

It is most likely the unwritten policy within members of UN Security
Council that a massive retalitation will never be made in response to
the detonation of a single warhead. China would likely say: "oops,
so sorry, it was an accident, some general had an itchy trigger
finger. We'll execute him and make reparations.". Plausible
deniability. In the meantime, our country is powerless to defend
Taiwan because while our teeth might be there, our supply lines still
originate in the US. China then conquers Taiwan with ease.

In a scenario like this, the entire country will be physically
unharmed but will be in chaos, needing operators with equipment not
damaged by EMP. I'd like my daughter to be able to help out if she
can.

That's all I have to say for tonight.

The Eternal Squire

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

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. :-)