_Experimental Methods_ is oriented toward the advanced amateur, so you
won't find the depth and level of math you would in a college text or a
specialized text on one of the many topics covered in that book.
However, there's a lot more depth than you'll find in something like the
_ARRL Handbook_. Another thing is that the authors are all experienced
and professional engineers who've spent years doing RF design, and all
know a very great deal about the covered topics. In my opinion, only
someone with a very deep and basic understanding of the fundamentals can
accurately explain theory in an intuitive and easy to understand way.
The authors have that understanding. I have no doubt you'll be very
pleased with the book.

Re test equipment: how about devices for measuring RF power, impedance,
frequency, inductance, capacitance, Q, spectra, noise figure, and
crystal characteristics?

I don't believe there's an example of a wideband VCO. The authors
concentrate a lot on keeping phase noise low, so use other methods to
achieve wideband operation than with a wideband VCO.

If you're looking for a more theoretical treatment of oscillators and
other RF circuits, I recommend Hayward's _Introduction to Radio
Frequency Design_, now also published by the ARRL. (You might find a
used first edition, published by Wiley as I recall.) After reading the
chapter on oscillators, you'll know enough to get a good start at least
at designing your own VCO.

There are a lot of practical tips and observations about oscillators in
_Oscillator Design and Computer Simulation_ by Randall Rhea (Noble
publishing, ISBN1-884932-30-4), although in my opinion it doesn't convey
as fundamental understanding of oscillator operation as Hayward's books.

Roy Lewallen, W7EL

James Fenech wrote:
Hi Roy,

thanks for the suggestion. I am considering buying this book. Can I ask how
much theory, and how deep does it go? I am an engineer (digital electornics
and software background) and actually like some theory to help me understand
what I am doing.

I already have some "real" test equipment, 50MHz CRO, signal generator,
multimeter, etc. So "simple" test equipment may not be too much of an
improvement.

I've looked over the internet, and some books that I have, but found no real
example circuit on wideband VCOs. The only "sort of close enough" circuit I
found is at:
http://www.newwaveinstruments.com/resources/rf_microwave_resources/sections/oscillator_vco_theory_design_circuit.htm#Voltage%2 0Controled%20Oscillator%20(VCO)%20Circuits
The second one down - Colpitts. Are there any such examples in this book?

Thanks,
James.


"Roy Lewallen" wrote in message
...

I highly recommend _Experimental Methods in RF Design_, by Hayward,
Cambell, and Larkin. It's published by the ARRL and available from them
and numerous other sources. Besides theory and a lot of real, practical,
tested circuits and projects, it includes simple test equipment you can
build yourself.

Roy Lewallen, W7EL

James Fenech wrote:

. . .
I have the ARRL handbook (1997 or so) but this doesn't have much in the

way

of theory. Is there any other reference anyone can recommend?
. . .

Thanks for the feedback Roy, I've now got the book on order. Unfortunately
I've now blown my book budget and will need to wait a while before ordering
anything else.

James.

"Roy Lewallen" wrote in message
...
_Experimental Methods_ is oriented toward the advanced amateur, so you
won't find the depth and level of math you would in a college text or a
specialized text on one of the many topics covered in that book.
However, there's a lot more depth than you'll find in something like the
_ARRL Handbook_. Another thing is that the authors are all experienced
and professional engineers who've spent years doing RF design, and all
know a very great deal about the covered topics. In my opinion, only
someone with a very deep and basic understanding of the fundamentals can
accurately explain theory in an intuitive and easy to understand way.
The authors have that understanding. I have no doubt you'll be very
pleased with the book.

Re test equipment: how about devices for measuring RF power, impedance,
frequency, inductance, capacitance, Q, spectra, noise figure, and
crystal characteristics?

I don't believe there's an example of a wideband VCO. The authors
concentrate a lot on keeping phase noise low, so use other methods to
achieve wideband operation than with a wideband VCO.

If you're looking for a more theoretical treatment of oscillators and
other RF circuits, I recommend Hayward's _Introduction to Radio
Frequency Design_, now also published by the ARRL. (You might find a
used first edition, published by Wiley as I recall.) After reading the
chapter on oscillators, you'll know enough to get a good start at least
at designing your own VCO.

There are a lot of practical tips and observations about oscillators in
_Oscillator Design and Computer Simulation_ by Randall Rhea (Noble
publishing, ISBN1-884932-30-4), although in my opinion it doesn't convey
as fundamental understanding of oscillator operation as Hayward's books.

Roy Lewallen, W7EL

James Fenech wrote:
Hi Roy,

thanks for the suggestion. I am considering buying this book. Can I ask
how
much theory, and how deep does it go? I am an engineer (digital
electornics
and software background) and actually like some theory to help me
understand
what I am doing.

I already have some "real" test equipment, 50MHz CRO, signal generator,
multimeter, etc. So "simple" test equipment may not be too much of an
improvement.

I've looked over the internet, and some books that I have, but found no
real
example circuit on wideband VCOs. The only "sort of close enough"
circuit I
found is at:

http://www.newwaveinstruments.com/resources/rf_microwave_resources/sections/oscillator_vco_theory_design_circuit.htm#Voltage%2 0Controled%20Oscillator%20(VCO)%20Circuits
The second one down - Colpitts. Are there any such examples in this
book?

Thanks,
James.


"Roy Lewallen" wrote in message
...

I highly recommend _Experimental Methods in RF Design_, by Hayward,
Cambell, and Larkin. It's published by the ARRL and available from them
and numerous other sources. Besides theory and a lot of real, practical,
tested circuits and projects, it includes simple test equipment you can
build yourself.

Roy Lewallen, W7EL

James Fenech wrote:

. . .
I have the ARRL handbook (1997 or so) but this doesn't have much in the

way

of theory. Is there any other reference anyone can recommend?
. . .

Thanks for the feedback Roy, I've now got the book on order. Unfortunately
I've now blown my book budget and will need to wait a while before ordering
anything else.

James.

"Roy Lewallen" wrote in message
...
_Experimental Methods_ is oriented toward the advanced amateur, so you
won't find the depth and level of math you would in a college text or a
specialized text on one of the many topics covered in that book.
However, there's a lot more depth than you'll find in something like the
_ARRL Handbook_. Another thing is that the authors are all experienced
and professional engineers who've spent years doing RF design, and all
know a very great deal about the covered topics. In my opinion, only
someone with a very deep and basic understanding of the fundamentals can
accurately explain theory in an intuitive and easy to understand way.
The authors have that understanding. I have no doubt you'll be very
pleased with the book.

Re test equipment: how about devices for measuring RF power, impedance,
frequency, inductance, capacitance, Q, spectra, noise figure, and
crystal characteristics?

I don't believe there's an example of a wideband VCO. The authors
concentrate a lot on keeping phase noise low, so use other methods to
achieve wideband operation than with a wideband VCO.

If you're looking for a more theoretical treatment of oscillators and
other RF circuits, I recommend Hayward's _Introduction to Radio
Frequency Design_, now also published by the ARRL. (You might find a
used first edition, published by Wiley as I recall.) After reading the
chapter on oscillators, you'll know enough to get a good start at least
at designing your own VCO.

There are a lot of practical tips and observations about oscillators in
_Oscillator Design and Computer Simulation_ by Randall Rhea (Noble
publishing, ISBN1-884932-30-4), although in my opinion it doesn't convey
as fundamental understanding of oscillator operation as Hayward's books.

Roy Lewallen, W7EL

James Fenech wrote:
Hi Roy,

thanks for the suggestion. I am considering buying this book. Can I ask
how
much theory, and how deep does it go? I am an engineer (digital
electornics
and software background) and actually like some theory to help me
understand
what I am doing.

I already have some "real" test equipment, 50MHz CRO, signal generator,
multimeter, etc. So "simple" test equipment may not be too much of an
improvement.

I've looked over the internet, and some books that I have, but found no
real
example circuit on wideband VCOs. The only "sort of close enough"
circuit I
found is at:

http://www.newwaveinstruments.com/resources/rf_microwave_resources/sections/oscillator_vco_theory_design_circuit.htm#Voltage%2 0Controled%20Oscillator%20(VCO)%20Circuits
The second one down - Colpitts. Are there any such examples in this
book?

Thanks,
James.


"Roy Lewallen" wrote in message
...

I highly recommend _Experimental Methods in RF Design_, by Hayward,
Cambell, and Larkin. It's published by the ARRL and available from them
and numerous other sources. Besides theory and a lot of real, practical,
tested circuits and projects, it includes simple test equipment you can
build yourself.

Roy Lewallen, W7EL

James Fenech wrote:

. . .
I have the ARRL handbook (1997 or so) but this doesn't have much in the

way

of theory. Is there any other reference anyone can recommend?
. . .

Hans Summers wrote:

See my spectrum analyser:
http://www.hanssummers.com/electroni...yser/index.htm
which has 145MHz 1st IF and covers right up to (and through!) the 1st IF,
using an SA602 VCO covering 145MHz to something like 300MHz with no problem
and apparently excellent linearity. The varicap is BB105. Dynamic range is
limited to something like 70dB by the choice of front end (SA602) but it's a
fun and useful project that is quite easy to build. If anyone wants the
circuit diagram and full construction details let me know.

I very much enjoyed seeing all the photos of your construction and
would like to receive the schematic and details. Thanks.

--
John Popelish

Hans Summers wrote:

See my spectrum analyser:
http://www.hanssummers.com/electroni...yser/index.htm
which has 145MHz 1st IF and covers right up to (and through!) the 1st IF,
using an SA602 VCO covering 145MHz to something like 300MHz with no problem
and apparently excellent linearity. The varicap is BB105. Dynamic range is
limited to something like 70dB by the choice of front end (SA602) but it's a
fun and useful project that is quite easy to build. If anyone wants the
circuit diagram and full construction details let me know.

I very much enjoyed seeing all the photos of your construction and
would like to receive the schematic and details. Thanks.

--
John Popelish

My comments are colored by experience desigining quite low noise, relitavely
narrow bandwidth VCOs, so all the other comments are very valid.

I will note that there are two aspects of noise to consider, that I can
think of off hand. One is that:
1) Too low of an absolute DC voltage on the varactors will make for a noisy
VCO and
2) A wide tuning range means that the varactor is relatively tightly
coupled into the oscillator which means that control line noise/spurs you'll
have to watch control line noise & spurs.
3) This also means the Varactors have more effect on the oscillator Q and
therefore can also mean increased noise.
OK nobody expects the Spanish inquisition.

If you can determine the actual noise performance and keep it in mind that
the analyzer has a noise limit, you'll be ok.

Been away from it too long and can't seem to recall why we used to use two,
back-to-back varactors...brain is full...seems like it was to reduce the
voltage across the varactor.

'guards, Steve K;9;D:C:I



"W3JDR" wrote in message
...
2:1 tuning range with varactor tuning is very doable in the frequency
range
he's considering. I've done 3:1 at lower frequencies. No steep hill at
all.

Joe
W3JDR


"Steve Nosko" wrote in message
...
You're climbing a steep hill here James. It is the % change in
frequency
that is the problem. Professional spec analysers use a 2 GHz LO with a
2:1
range (to scan 0-2GHz), but I believe that is a magnetically tuned YIG
resonator. If you could get the frequency higher, so the sweep range is
narrower, then mix to the desired freq with a balanced mixer...that
would
be
an easier VCO design.

Steve
K;9;d;c;i

The punctuation is my feeble attempt at spam-bot blocking.


"James Fenech" wrote in message
...
Hi Roy,

thanks for the suggestion. I am considering buying this book. Can I
ask
how
much theory, and how deep does it go? I am an engineer (digital
electornics
and software background) and actually like some theory to help me
understand
what I am doing.

I already have some "real" test equipment, 50MHz CRO, signal
generator,
multimeter, etc. So "simple" test equipment may not be too much of an
improvement.

I've looked over the internet, and some books that I have, but found
no
real
example circuit on wideband VCOs. The only "sort of close enough"
circuit
I
found is at:



http://www.newwaveinstruments.com/resources/rf_microwave_resources/sections/oscillator_vco_theory_design_circuit.htm#Voltage%2 0Controled%20Oscillator%20(VCO)%20Circuits
The second one down - Colpitts. Are there any such examples in this
book?

Thanks,
James.


"Roy Lewallen" wrote in message
...
I highly recommend _Experimental Methods in RF Design_, by Hayward,
Cambell, and Larkin. It's published by the ARRL and available from
them
and numerous other sources. Besides theory and a lot of real,
practical,
tested circuits and projects, it includes simple test equipment you
can
build yourself.

Roy Lewallen, W7EL

James Fenech wrote:
. . .
I have the ARRL handbook (1997 or so) but this doesn't have much
in
the
way
of theory. Is there any other reference anyone can recommend?
. . .

My comments are colored by experience desigining quite low noise, relitavely
narrow bandwidth VCOs, so all the other comments are very valid.

I will note that there are two aspects of noise to consider, that I can
think of off hand. One is that:
1) Too low of an absolute DC voltage on the varactors will make for a noisy
VCO and
2) A wide tuning range means that the varactor is relatively tightly
coupled into the oscillator which means that control line noise/spurs you'll
have to watch control line noise & spurs.
3) This also means the Varactors have more effect on the oscillator Q and
therefore can also mean increased noise.
OK nobody expects the Spanish inquisition.

If you can determine the actual noise performance and keep it in mind that
the analyzer has a noise limit, you'll be ok.

Been away from it too long and can't seem to recall why we used to use two,
back-to-back varactors...brain is full...seems like it was to reduce the
voltage across the varactor.

'guards, Steve K;9;D:C:I



"W3JDR" wrote in message
...
2:1 tuning range with varactor tuning is very doable in the frequency
range
he's considering. I've done 3:1 at lower frequencies. No steep hill at
all.

Joe
W3JDR


"Steve Nosko" wrote in message
...
You're climbing a steep hill here James. It is the % change in
frequency
that is the problem. Professional spec analysers use a 2 GHz LO with a
2:1
range (to scan 0-2GHz), but I believe that is a magnetically tuned YIG
resonator. If you could get the frequency higher, so the sweep range is
narrower, then mix to the desired freq with a balanced mixer...that
would
be
an easier VCO design.

Steve
K;9;d;c;i

The punctuation is my feeble attempt at spam-bot blocking.


"James Fenech" wrote in message
...
Hi Roy,

thanks for the suggestion. I am considering buying this book. Can I
ask
how
much theory, and how deep does it go? I am an engineer (digital
electornics
and software background) and actually like some theory to help me
understand
what I am doing.

I already have some "real" test equipment, 50MHz CRO, signal
generator,
multimeter, etc. So "simple" test equipment may not be too much of an
improvement.

I've looked over the internet, and some books that I have, but found
no
real
example circuit on wideband VCOs. The only "sort of close enough"
circuit
I
found is at:



http://www.newwaveinstruments.com/resources/rf_microwave_resources/sections/oscillator_vco_theory_design_circuit.htm#Voltage%2 0Controled%20Oscillator%20(VCO)%20Circuits
The second one down - Colpitts. Are there any such examples in this
book?

Thanks,
James.


"Roy Lewallen" wrote in message
...
I highly recommend _Experimental Methods in RF Design_, by Hayward,
Cambell, and Larkin. It's published by the ARRL and available from
them
and numerous other sources. Besides theory and a lot of real,
practical,
tested circuits and projects, it includes simple test equipment you
can
build yourself.

Roy Lewallen, W7EL

James Fenech wrote:
. . .
I have the ARRL handbook (1997 or so) but this doesn't have much
in
the
way
of theory. Is there any other reference anyone can recommend?
. . .

Steve,
I think the main reason for back-to-back diodes is to prevent rectification
of the RF. Rectification can cause several bad things, including pushing DC
current back out the tuning voltage line, instability, and increased phase
noise. Having said that, I tried back-to-back diodes a couple times and I
don't ever recall ending up with it in the final design, so it must not have
added all that much value. On the negative side, it halves the capacitance.
One technique to improve the phase noise in wide-band VCO's was shown by
Ulrich Rhode. He uses several diodes in parallel in order to decrease the RF
current in each diode, reportedly lowering losses and improving noise. I
never tried it myself.

Joe
W3JDR


"Steve Nosko" wrote in message
...
My comments are colored by experience desigining quite low noise,
relitavely
narrow bandwidth VCOs, so all the other comments are very valid.

I will note that there are two aspects of noise to consider, that I can
think of off hand. One is that:
1) Too low of an absolute DC voltage on the varactors will make for a
noisy
VCO and
2) A wide tuning range means that the varactor is relatively tightly
coupled into the oscillator which means that control line noise/spurs
you'll
have to watch control line noise & spurs.
3) This also means the Varactors have more effect on the oscillator Q and
therefore can also mean increased noise.
OK nobody expects the Spanish inquisition.

If you can determine the actual noise performance and keep it in mind that
the analyzer has a noise limit, you'll be ok.

Been away from it too long and can't seem to recall why we used to use
two,
back-to-back varactors...brain is full...seems like it was to reduce the
voltage across the varactor.

'guards, Steve K;9;D:C:I



"W3JDR" wrote in message
...
2:1 tuning range with varactor tuning is very doable in the frequency
range
he's considering. I've done 3:1 at lower frequencies. No steep hill at
all.

Joe
W3JDR


"Steve Nosko" wrote in message
...
You're climbing a steep hill here James. It is the % change in
frequency
that is the problem. Professional spec analysers use a 2 GHz LO with
a
2:1
range (to scan 0-2GHz), but I believe that is a magnetically tuned YIG
resonator. If you could get the frequency higher, so the sweep range
is
narrower, then mix to the desired freq with a balanced mixer...that
would
be
an easier VCO design.

Steve
K;9;d;c;i

The punctuation is my feeble attempt at spam-bot blocking.


"James Fenech" wrote in message
...
Hi Roy,

thanks for the suggestion. I am considering buying this book. Can I
ask
how
much theory, and how deep does it go? I am an engineer (digital
electornics
and software background) and actually like some theory to help me
understand
what I am doing.

I already have some "real" test equipment, 50MHz CRO, signal
generator,
multimeter, etc. So "simple" test equipment may not be too much of
an
improvement.

I've looked over the internet, and some books that I have, but found
no
real
example circuit on wideband VCOs. The only "sort of close enough"
circuit
I
found is at:




http://www.newwaveinstruments.com/resources/rf_microwave_resources/sections/oscillator_vco_theory_design_circuit.htm#Voltage%2 0Controled%20Oscillator%20(VCO)%20Circuits
The second one down - Colpitts. Are there any such examples in this
book?

Thanks,
James.


"Roy Lewallen" wrote in message
...
I highly recommend _Experimental Methods in RF Design_, by
Hayward,
Cambell, and Larkin. It's published by the ARRL and available from
them
and numerous other sources. Besides theory and a lot of real,
practical,
tested circuits and projects, it includes simple test equipment
you
can
build yourself.

Roy Lewallen, W7EL

James Fenech wrote:
. . .
I have the ARRL handbook (1997 or so) but this doesn't have much
in
the
way
of theory. Is there any other reference anyone can recommend?
. . .

Steve,
I think the main reason for back-to-back diodes is to prevent rectification
of the RF. Rectification can cause several bad things, including pushing DC
current back out the tuning voltage line, instability, and increased phase
noise. Having said that, I tried back-to-back diodes a couple times and I
don't ever recall ending up with it in the final design, so it must not have
added all that much value. On the negative side, it halves the capacitance.
One technique to improve the phase noise in wide-band VCO's was shown by
Ulrich Rhode. He uses several diodes in parallel in order to decrease the RF
current in each diode, reportedly lowering losses and improving noise. I
never tried it myself.

Joe
W3JDR


"Steve Nosko" wrote in message
...
My comments are colored by experience desigining quite low noise,
relitavely
narrow bandwidth VCOs, so all the other comments are very valid.

I will note that there are two aspects of noise to consider, that I can
think of off hand. One is that:
1) Too low of an absolute DC voltage on the varactors will make for a
noisy
VCO and
2) A wide tuning range means that the varactor is relatively tightly
coupled into the oscillator which means that control line noise/spurs
you'll
have to watch control line noise & spurs.
3) This also means the Varactors have more effect on the oscillator Q and
therefore can also mean increased noise.
OK nobody expects the Spanish inquisition.

If you can determine the actual noise performance and keep it in mind that
the analyzer has a noise limit, you'll be ok.

Been away from it too long and can't seem to recall why we used to use
two,
back-to-back varactors...brain is full...seems like it was to reduce the
voltage across the varactor.

'guards, Steve K;9;D:C:I



"W3JDR" wrote in message
...
2:1 tuning range with varactor tuning is very doable in the frequency
range
he's considering. I've done 3:1 at lower frequencies. No steep hill at
all.

Joe
W3JDR


"Steve Nosko" wrote in message
...
You're climbing a steep hill here James. It is the % change in
frequency
that is the problem. Professional spec analysers use a 2 GHz LO with
a
2:1
range (to scan 0-2GHz), but I believe that is a magnetically tuned YIG
resonator. If you could get the frequency higher, so the sweep range
is
narrower, then mix to the desired freq with a balanced mixer...that
would
be
an easier VCO design.

Steve
K;9;d;c;i

The punctuation is my feeble attempt at spam-bot blocking.


"James Fenech" wrote in message
...
Hi Roy,

thanks for the suggestion. I am considering buying this book. Can I
ask
how
much theory, and how deep does it go? I am an engineer (digital
electornics
and software background) and actually like some theory to help me
understand
what I am doing.

I already have some "real" test equipment, 50MHz CRO, signal
generator,
multimeter, etc. So "simple" test equipment may not be too much of
an
improvement.

I've looked over the internet, and some books that I have, but found
no
real
example circuit on wideband VCOs. The only "sort of close enough"
circuit
I
found is at:




http://www.newwaveinstruments.com/resources/rf_microwave_resources/sections/oscillator_vco_theory_design_circuit.htm#Voltage%2 0Controled%20Oscillator%20(VCO)%20Circuits
The second one down - Colpitts. Are there any such examples in this
book?

Thanks,
James.


"Roy Lewallen" wrote in message
...
I highly recommend _Experimental Methods in RF Design_, by
Hayward,
Cambell, and Larkin. It's published by the ARRL and available from
them
and numerous other sources. Besides theory and a lot of real,
practical,
tested circuits and projects, it includes simple test equipment
you
can
build yourself.

Roy Lewallen, W7EL

James Fenech wrote:
. . .
I have the ARRL handbook (1997 or so) but this doesn't have much
in
the
way
of theory. Is there any other reference anyone can recommend?
. . .

One technique to improve the phase noise in wide-band VCO's was shown by
Ulrich Rhode. He uses several diodes in parallel in order to decrease the
RF
current in each diode, reportedly lowering losses and improving noise. I
never tried it myself.

If the diodes are the limiting factor, it can help.
The second diode seemed to do the most good,
the third, a little more, but any more didn't help
(in my designs).

The way the varactor is made will affect the
noise performance. Ask the manufacturers
which process yields their best phase-noise
performance. Most of them are very helpful.
As I recall, planar, epitaxial construction,
with thermal compression bonded leads
gave my best results. Hyperabrupt diodes
gave the worst. But things change rapidly
these days, so ask.

73, John - K6QQ