In message , William
Sommerwerck writes
You would find it rather difficult to FM a crystal oscillator.
Possible, but difficult.

Not really. It's done all the time in temperature-compensated oscillators,
simply by varying the series or load capacitance.


OK then - 'Possible, but much more difficult than with a free-running
L-C circuit'.

When an oscillator is crystal controlled, to get a lot of FM, it usually
takes a bit more than 'slipping a variap' into the circuit. You usually
have to use some form of VXO circuit. Even then, the amount of FM you
get can depend a lot on the characteristics of the crystal. And it may
not be very linear. But it all depends on what you need.

Some early crystal-controlled FM equipment avoids the problems of FMing
the crystal itself. Instead, in a later stage they phase-modulate the
signal (producing a predictable amount of PM) and, of course, multiply
up to the final frequency.

Ian.
--

No mention of "antique" at all, just "one tube", and when I look at
a 6J6 I see one tube... unless I have had a few too many then?

If someone said "design such-and-such using a single tube", would it be fair
to use a Compactron?

When you describe a circuit as being "single-tube", the implication is that
the tube is not a multi-section device.

In article ,
"William Sommerwerck" wrote:

No mention of "antique" at all, just "one tube", and when I look at
a 6J6 I see one tube... unless I have had a few too many then?

If someone said "design such-and-such using a single tube", would it be fair
to use a Compactron?

Yes, a tube is a tube is a tube.

When you describe a circuit as being "single-tube", the implication is that
the tube is not a multi-section device.

No, you have to be specific if you mean a single section tube.


Regards,

John Byrns

--
Surf my web pages at, http://fmamradios.com/

No ,

It uses a single 2 section tube


tube Pronunciation: \'tüb, 'tyüb\
Function:noun
Etymology:French, from Latin tubus; akin to Latin tuba trumpet
Date:1651

a hollow elongated cylinder;

electron tube

Main Entry:electron tube
Function:noun
Date:1922
an electronic device in which conduction by electrons takes place through a vacuum or a gaseous medium within a sealed glass or metal container and which has various uses based on the controlled flow of electrons




--
Carl
WA1KPD
Visit My Boatanchor Collection at http://home.comcast.net/~chnord/wa1kpd.html

"William Sommerwerck" wrote in message . ..
Excuse me, but that circuit uses two tubes.

Terry,
I'll bet your sorry you ever shared this!

--
Carl
WA1KPD
Visit My Boatanchor Collection at
http://home.comcast.net/~chnord/wa1kpd.html

"TerryJ" suptjudatcomcastdotnet wrote in message
...
FM with one tube.....

"TerryJ" suptjudatcomcastdotnet wrote in message
...
Note the one MHz crystal oscillator? AM.....
"Johnny Byrns" wrote in message
...
TerryJ wrote:

Capable of 100% modulation and has fairly good fidelity.

How do I tell if it uses AM or FM transmission signals? The diagram
shows nothing in reference to a FM or AM transmission bands.

--
Johnny Byrns (http://www.fmamradios.com/Johnny's.html)

Carl WA1KPD wrote:
Terry,
I'll bet your sorry you ever shared this!
-------------------------------------------------
Terry -

Despite the rather senseless carping (c'mon boys, cut the crap!), this
is cool! Thanks for posting it!

Bill

Carl WA1KPD wrote:

No ,

It uses a single 2 section tube


tube Pronunciation: \?tüb, ?tyüb\
Function:noun
Etymology:French, from Latin tubus; akin to Latin tuba trumpet
Date:1651

a hollow elongated cylinder;


electron tube

Main Entry:electron tube
Function:noun
Date:1922
an electronic device in which conduction by electrons takes place
through a vacuum or a gaseous medium within a sealed glass or metal
container and which has various uses based on the controlled flow of
electrons



Please don't use HTML The text in your message is just streaks
across the monitor.

--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

Carl WA1KPD wrote:
Terry,
I'll bet your sorry you ever shared this!

That's like an auction I'm running now, for a (pair of 7591's). I have
gotten four questions on how many tubes there are, one tube, two pair
etc etc. Think shoes.Ken

Nicely done. I like the dual varactor arrangement, which should have
a lot of advantages over a single diode. All in all, simple and
elegant!

Pete

Despite the rather senseless carping (c'mon boys, cut the crap!), this is
cool! Thanks for posting it!

I agree. An interesting post. And now for my usual dumb questions :-)

1. Have you built one (or more) and if so, could we see a photo?

2. What do you mean by "star grounding technique?"

Phil Nelson