audio recording on IC -help wanted

[ted]

John, thanks for your comments

Had a quick rummage through a few issues but couldn't spot a "Ted"
or an
"Edward" (ah-ha an alias?, audio themes?). A title or two would help
focus.

Try Eddy...)

I can only speak for myself but I know it's difficult to list what's
liable
to catch my attention in a magazine. E.g. nowadays I've little
interest in
any audio subject but ... an article turned up by Doug' Self on
analogue-switching that I found really thought provoking. Capacitor
quality,
held zilch interest until Cyril started going on about it. I'd no
feeling
for sampling method until Ian Hickman wrote up his experience
avalanching a
transistor.
These guys are incredibly knowledgeable about their fields, and

whatever they write about makes interesting

reading, even if you are not too interested in the subject. The
downside is that there aren't that many people

around willing to put so much effort and get paid very little for it.
Once upon a time maybe, but not

nowadays...So the first problem is the lack of quality writers..

I think it isn't the subject headings or topics that make or break a
magazine, it's the obvious knowledge, love of their subjects and
level of
detail that some authors can introduce.
Exactly

times have changed and Kryten rightly notes that few people are now
in a position to follow the subject. Hence a lack of motivation
for authors to promulgate their enthusiasms amongst a wide
readership.

Agree. Nowadays "instant satisfaction" is the name of the game. The
common way for engineers to get to know a new

technology such as Bluetooth, is to buy a ready made module and use it
off the shelf. If you try to explain how

it all works in any detail, you lose your audience. Also, new
technology products are not only complex to

understand, but also pretty boring to describe. Part of the reason is
that they are designed by consortiums who

complicate the product and their functions no end.

For me, a big no-no, is any magazine article designed to provide an
'overview' of some technical product or process or technique.
Unfortunately
there seems more and more of this type of article turning up in the
(pay
for) magazines. Overviews are the easy bit and are not enough.
Mainly it is because it is copied from some other already existing

text. To write a decently descriptive article

on say how IEE802 works, you need several weeks research: decyphering
the standards, decoding the undocumented

bits, emailing people for information etc. Not far from the amount of
work needed for an MSc Thesis...

They seem to change EW editors every five minutes.
I think the main reason is that they are trying to increase

circulation figures (about 10-12k at present I guess)

The audience is there, cOnsidering the IEE has over 120k members. I
just don't know how these mags can be made

attractive to them.

What's sorely missing
from the mag' is some kind of continuity, like a monthly or even
occasional,
Alastair Cooke style, Letter-from-the-trenches.
Maybe you can step onto the crease?.
There is something there. When I get the New Scientist, the first

thing I turn to is the "back page" In one of

the mags (Television I think) there used to be a column "a day in the
life of a service engineer" First thing I

used to read, quite readable it was too..

 

[John Woodgate]

I read in sci.electronics.design that ted <edaudio2000@yahoo.co.uk>
wrote (in <c54bf83f.0502240337.65a478b1@posting.google.com&gt about
'Elektor Electronics new website', on Thu, 24 Feb 2005:

In one of

the mags (Television I think) there used to be a column "a day in the
life of a service engineer" First thing I

used to read, quite readable it was too..

You mean 'What a Life!' by Donald Bullock? It's still there, but not
always at the back.
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk

 

[Kryten]

"ted" <edaudio2000@yahoo.co.uk> wrote in message
news:c54bf83f.0502240337.65a478b1@posting.google.com...

So the first problem is the lack of quality writers.

I suspect that the population of good writers has not gone down too much.

However, if they are smart enough to write such articles they can also spot
that the payment divided by number of hours is less than minimum wage.

They seem to change EW editors every five minutes.
I think the main reason is that they are trying to increase
circulation figures (about 10-12k at present I guess)

I suspect there is no "they" to change editors,
total staff is unlikely to be more than the editor and a p.a.

Maybe people take on the business, find out how hard it is to fill the
magazine, then sell the business on a.s.a.p.

Svetlana has correctly observed that selling babble like the
magnetoaetherial tunnel and the Catt blather is not a viable long term
option. Selling trade press releases may not be either, since these are
given away in the free trade papers.

Maybe the readership has declined so far that there isn't enough money to
pay enough to entice people to write. Even if a staff of just two paid
themselves a modest 20K each, they'd need to make Ł4 on each of 10K mags
sold.

Perhaps we should ask the Audit Bureau of Circulation what the actual figure
is.

K.

 

[John Woodgate]

I read in sci.electronics.design that Kryten <kryten_droid_obfusticator@
ntlworld.com> wrote (in <KxkTd.221$D_.53@newsfe5-gui.ntli.net&gt about
'Elektor Electronics new website', on Thu, 24 Feb 2005:

I suspect there is no "they" to change editors,
total staff is unlikely to be more than the editor and a p.a.

There are a few more than that: about six on the masthead, including a
'Publishing Director' who is the real boss.
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk

 

[Kryten]

"John Woodgate" <jmw@jmwa.demon.contraspam.yuk> wrote in message
news:GDTkG3KHtjHCFwaB@jmwa.demon.co.uk...

There are a few more than that: about six on the masthead, including a
'Publishing Director' who is the real boss.

How many do practical work, and how many are just named because they own the
business?

I once worked at an engineering company with a managing director, financial
director (his wife), a sales director, a secretary, a one engineer (me).
Never work for a company with more people directing than doing...

 

[john jardine]

"ted" <edaudio2000@yahoo.co.uk> wrote in message
news:c54bf83f.0502240337.65a478b1@posting.google.com...
[clip]

They seem to change EW editors every five minutes.

I think the main reason is that they are trying to increase
circulation figures (about 10-12k at present I guess)

The audience is there, considering the IEE has over 120k members. I
just don't know how these mags can be made attractive to them.

Good point. Myself I don't think it's any longer possible to increase reader
numbers. The whole industry has these past 30 years devolved into say an
85%-15% digital/analogue split, maybe finally to stablize at a 90%-10%
level. The people who buy the mag's just seem born that way and curious wrt
analogue systems. Digital systems/process/programming etc being regarded
only as a means-to-an-end.
The uni's must now turn out 85% DSP/computing specialists. But how many of
these are willing to fork out Ł3.25 of their own money for a special
interest 'DSP World' or 'Practical DSP' mag'?. How many programming mag's
are even on sale?.
Over the years I've seen 3 purely 'programming' offerings survive for one
issue only, yet I've a couple of volumes of pre-war Practical Wireless where
there was sufficient interest for (incredible nowadays) each issue to be
printed weekly.

Anyways ...
I found 'em!. (well I think the monika's right, shame otherwise

Thought I'd lost a couple of mags but you might be pleased to hear they were
found filed in the "In case of this requirement, mug up on these selected
articles before looking anywhere else" bookshelf section, (web I/O and USB
Scope).
I especially liked the 'Super regen' article. This kind of thing appeals to
me. It's off the beaten track yet offered oodles of detail and discussion.
I liked the FPGA stuff. Another article in this area wouldn't be amiss.
Maybe using Farnell available I.C's, and low (or zero) cost development kit,
article homing in on something like a fast SIN/COS converter using say
CORDIC type structures.
Essentially you seem to be writing stuff that will be of interest to readers
of EW. Shurely we're all basically enthusiasts, so whatever it is that
interests you, should also be of some interest to us. Tell us about anything
that takes your fancy!. Absolutely no chance of paying any bills but you'd
earn respect from the soldiers.

While rummaging through the issues back to 1988 I spotted a few articles
that I remember well and would like to see more of. (A personal viewpoint
and probably not representative, as I'm a test equipment nut).
March 2005. Emil Vladkov.
Sept 2004. Emil Vladkov.
May 2004. Alan Bates
March 2004. David Poynting.
October 2003. Dewald de Lange.
Nov/Dec 2002. Nic Hamilton.
December 2003 issue. Pushed most of my buttons.
Also found interesting:
December 1988. Pappas. Obolensky.
I also honestly like reading Catt.

regards
john

 

[John Woodgate]

I read in sci.electronics.design that ted <edaudio2000@yahoo.co.uk>
wrote (in <c54bf83f.0502250220.7575ffdd@posting.google.com&gt about
'Elektor Electronics new website', on Fri, 25 Feb 2005:

I think electronics has matured to such an extent that newcomers (eg uni
students) are not the inquisitive/creative types any more, but simply
implementers. It has become like other professions like accountancy and
dentistry. Learn the trade, use the tools, and that's it. No
research/innovation involved (as it used to be the case) when engineers
had to be innovative in their designs in order to get ahead.

This is largely due to digital technology, and the enormous explosion of
capability that it's produced. Why bother with a clever analogue design
when you can throw a million transistors and a gigabyte of memory at the
project?

I'm not denigrating digital technology - it enables us to do a lot of
extremely useful things that are impossible, or virtually so, in
analogue, like a hand-held audio spectrum analyser. But almost all the
intellectual exercise in that, and in much else, is in software, not
hardware.
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk

 

[Rich Grise]

On Sat, 26 Feb 2005 11:44:41 +0000, John Woodgate wrote:

I read in sci.electronics.design that ted <edaudio2000@yahoo.co.uk
wrote (in <c54bf83f.0502260244.66776495@posting.google.com&gt about
'Elektor Electronics new website', on Sat, 26 Feb 2005:
"Graham W" <graham@his.com.puter.INVALID> wrote in message news:<421f5d51$0$1676
6$ed2619ec@ptn-nntp-reader02.plus.net>...
ted wrote:
[...]
There are a few gems around (unfort, not enough). I particularly like
innovative use of existing cheap technology. My favourite one was the
one about a sensing microscope made by attaching a tinly cantilever to
a "cut in half" piezo sounder. The tiny vibrations caused the
cantilever to move by tiny amounts causing capacitive changes,
brilliant!

That's the long way round of making a record-player (phonograph)
crystal pick-up cartridge! I wonder if he had considered one?

Oh gosh, it was much "cleverer" than that... Cantilevering the
needle's base between the two halves of the piezo allowed for very
accurate side to side movement of the tip by a few micrometers, far
more precise than a gramophone's needle.

Have a look at the groove pitch on an LP, and then consider that signals
well over 40 dB below that can be recorded and played, preserving the
waveform.

So, given this groove pitch, how many grooves are there, on average, on
one side of a typical LP?

Thanks,
Rich

 

[ted]

John Woodgate <jmw@jmwa.demon.contraspam.yuk> wrote in message news:<IF3HHqEpEGICFwSj@jmwa.demon.co.uk>...

I read in sci.electronics.design that ted <edaudio2000@yahoo.co.uk
wrote (in <c54bf83f.0502260244.66776495@posting.google.com&gt about
'Elektor Electronics new website', on Sat, 26 Feb 2005:
"Graham W" <graham@his.com.puter.INVALID> wrote in message news:<421f5d51$0$1676
6$ed2619ec@ptn-nntp-reader02.plus.net>...

ted wrote:
Have a look at the groove pitch on an LP, and then consider that signals
well over 40 dB below that can be recorded and played, preserving the
waveform.
A piezo gives far less displacement per unit volt applied. Several

volts for a few micrometer span. It also has a low mechanical source
resistance so that displacement is decently proportional to the
voltage applied, even against the back force generated by the electric
charge between the needle and the baseplate.

Also a cartridge is a velocity response device, difficult to use in a
closed loop positional system as required for a microscope.

 

[John Woodgate]

I read in sci.electronics.design that ted <edaudio2000@yahoo.co.uk>
wrote (in <c54bf83f.0502261046.1fd230f4@posting.google.com&gt about
'Elektor Electronics new website', on Sat, 26 Feb 2005:

John Woodgate <jmw@jmwa.demon.contraspam.yuk> wrote in message news:<IF3HHqEpEGI
CFwSj@jmwa.demon.co.uk>...
I read in sci.electronics.design that ted <edaudio2000@yahoo.co.uk
wrote (in <c54bf83f.0502260244.66776495@posting.google.com&gt about
'Elektor Electronics new website', on Sat, 26 Feb 2005:
"Graham W" <graham@his.com.puter.INVALID> wrote in message
news:<421f5d51$0$1676
6$ed2619ec@ptn-nntp-reader02.plus.net>...

ted wrote:
Have a look at the groove pitch on an LP, and then consider that signals
well over 40 dB below that can be recorded and played, preserving the
waveform.
A piezo gives far less displacement per unit volt applied. Several
volts for a few micrometer span. It also has a low mechanical source
resistance so that displacement is decently proportional to the
voltage applied, even against the back force generated by the electric
charge between the needle and the baseplate.

Also a cartridge is a velocity response device, difficult to use in a
closed loop positional system as required for a microscope.

You clearly speak of what you do not know. Piezo phono pickups are
*amplitude* sensitive, in that the give a flat response with the RIAA
amplitude/frequency curve. **Magnetic** pickups are velocity sensitive.

There are 'crystal' phono pickups, using Rochelle salt bender bimorphs,
and 'ceramic' pickups, made of barium titanate, also bender bimorphs.
These have capacitive impedances, corresponding roughly to capacitors of
600 pF to 1.5 nF. Typical open-circuit outputs from a 1 kHz 5 cm/s
recorded signal range from 1 to 8 mV.
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk

 

[mc]

A piezo gives far less displacement per unit volt applied. Several
volts for a few micrometer span. It also has a low mechanical source
resistance so that displacement is decently proportional to the
voltage applied, even against the back force generated by the electric
charge between the needle and the baseplate.

Also a cartridge is a velocity response device, difficult to use in a
closed loop positional system as required for a microscope.

I think you're thinking of magnetic cartridges. There are also
piezoelectric cartridges, popular in cheap record players in the 1950s
because they gave nearly a volt of output (with high impedance of course),
suitable for amplification by a single tube.

 

[Watson A.Name - \"Watt Su]

"Jim Thompson" <thegreatone@example.com> wrote in message
news:tqu321dqvbjt3tk5ojuimjbp2qf9ujnfrr@4ax.com...

On Sun, 27 Feb 2005 08:42:35 -0800, "Watson A.Name - \"Watt Sun, the
Dark Remover\"" <NOSPAM@dslextreme.com> wrote:

[snip]

The spammers are here, in the U.S. The laws don't have much of an
effect on them, either.

[snip]

No, your list isn't a current list; you have to delete the
non-functioning records from the list, too.

[snip]
[snip]

I average 6 spam E-mails per month, all of which are caught by my
filtering and go straight to Trash.

All of them go to a specific publicly-known E-mail address which I'm
about to replace with a form on my website.

Then I should be receiving zero.

...Jim Thompson
--

C'mon, Jim. We all know that your son is doing that for you. ;-)

When you say form, what does that say? A specific error message that
refers to another email address?

On occasion I still troll the web for instances of my old email
addresses. I still find them from prehistoric times, back when I had
freebie educational email addresses. They just won't go away, and the
spammers still scrape them off the net, trying to sell millions of them
to other spammers. I was getting spam on my unix shell acct for a
decade, even tho the address hadn't been used for almost that long.

 

[John Fields]

On 28 Feb 2005 11:23:50 -0800, "Tim Shoppa" <shoppa@trailing-edge.com>
wrote:

Are "overtone" crystals cut differently than "fundamental" crystals?
Or are they just specified differently?

In particular, say I took a garden-variety 20MHz fundamental
microprocessor crystal and instead used it at its fifth overtone,
trying to hit 100 MHz. The LC network is there to make sure that it's
on its fifth overtone. Will this "misuse" mean that the oscillator
will be harder to start up, less stable, more noisy, ???, than a
crystal oscillator made out of a real overtone crystal? I don't mind
if I "miss" 100 MHz by a several tens or hundreds of ppm, as long as
it's stable there.

---
You can use a fundamental mode crystal as an overtone oscillator, but
even if you can get it to oscillate, it won't be generating an
overtone at 100MHz, since overtone modes of oscillation aren't
harmonically related to the fundamental. It's more like the slab of
crystal is vibrating like the drumhead of a steel drum with small
areas of the slab vibrating at higher frequencies, instead of the
entire slab virbarting at just one frequency.

Check out "Chladni patterns" if you're interested.

Here's some pattrens for violin tops and circular plates:

http://www.phys.unsw.edu.au/~jw/chladni.html
---

If anyone knows of a place that ships off-the-shelf 100 MHz fifth or
seventh overtone crystals, I can avoid this whole exercise....

---
Anybody who makes crystals ought to be able to help you out; here's a
start:

http://www.icmfg.com/

--
John Fields

 

[Tim Wescott]

John Fields wrote:

On 28 Feb 2005 11:23:50 -0800, "Tim Shoppa" <shoppa@trailing-edge.com
wrote:


Are "overtone" crystals cut differently than "fundamental" crystals?
Or are they just specified differently?

In particular, say I took a garden-variety 20MHz fundamental
microprocessor crystal and instead used it at its fifth overtone,
trying to hit 100 MHz. The LC network is there to make sure that it's
on its fifth overtone. Will this "misuse" mean that the oscillator
will be harder to start up, less stable, more noisy, ???, than a
crystal oscillator made out of a real overtone crystal? I don't mind
if I "miss" 100 MHz by a several tens or hundreds of ppm, as long as
it's stable there.


---
You can use a fundamental mode crystal as an overtone oscillator, but
even if you can get it to oscillate, it won't be generating an
overtone at 100MHz, since overtone modes of oscillation aren't
harmonically related to the fundamental. It's more like the slab of
crystal is vibrating like the drumhead of a steel drum with small
areas of the slab vibrating at higher frequencies, instead of the
entire slab virbarting at just one frequency.

Check out "Chladni patterns" if you're interested.

Here's some pattrens for violin tops and circular plates:

http://www.phys.unsw.edu.au/~jw/chladni.html
---


If anyone knows of a place that ships off-the-shelf 100 MHz fifth or
seventh overtone crystals, I can avoid this whole exercise....


---
Anybody who makes crystals ought to be able to help you out; here's a
start:

http://www.icmfg.com/

In an AT cut crystal the overtone modes are close, but not exactly on,
the odd harmonics of the fundamental. Furthermore, all of the
literature that I've read on AT cut crystals reports that they vibrate
in the bulk of the crystal, in shear mode -- see figure 7 here:
http://literature.agilent.com/litweb/pdf/5965-7662E.pdf.

Perhaps you're thinking of SAW devices?

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

 

[Frank Moe]

"Tim Shoppa" <shoppa@trailing-edge.com> wrote in message news:<1109618629.998142.124510@o13g2000cwo.googlegroups.com>...

Are "overtone" crystals cut differently than "fundamental" crystals?
Or are they just specified differently?

In particular, say I took a garden-variety 20MHz fundamental
microprocessor crystal and instead used it at its fifth overtone,
trying to hit 100 MHz. The LC network is there to make sure that it's
on its fifth overtone. Will this "misuse" mean that the oscillator
will be harder to start up, less stable, more noisy, ???, than a
crystal oscillator made out of a real overtone crystal? I don't mind
if I "miss" 100 MHz by a several tens or hundreds of ppm, as long as
it's stable there.

If anyone knows of a place that ships off-the-shelf 100 MHz fifth or
seventh overtone crystals, I can avoid this whole exercise....

Tim.

Tim,

to get optimum performance one would grind the 100MHz 5.OT finer or
even polish it, and the thickness of the electrodes might be different
to get optimum Q.
But you should be ok by using a 20MHz fundamental in its 5th.

There are also manufacturers that make 100 in fundamental (up to about
200MHz), and many should have 100 in 5th as standard part...

Frank

 

[John Fields]

On Mon, 28 Feb 2005 18:33:53 -0800, "RST Engineering"
<jim@rstengineering.com> wrote:

That is total and absolute bullpuckey.

Jim


---
You can use a fundamental mode crystal as an overtone oscillator, but
even if you can get it to oscillate, it won't be generating an
overtone at 100MHz, since overtone modes of oscillation aren't
harmonically related to the fundamental.

---
RST what???

--
John Fields

 

[John Fields]

On Tue, 1 Mar 2005 08:12:48 -0800, "RST Engineering \(jw\)"
<jim@rstengineering.com> wrote:

Sorry, dude, 50 years of designing with crystals, right from when I ground
my first surplus WWII rock on a piece of glass with toothpaste as the
abrasive says that what the original poster asked is correct.

Will the harmonic be precise? No. Will it be "close", which is what the
original poster asked? You bet. Depending on the oscillator circuit, can
it be "pulled" on frequency? Perhaps.

But to say that the crystal doesn't resonate anywhere near the harmonic is,
as I said, bullpuckey.

---
Sorry, dude, no matter how much time you've got in, if you go back
and read my post, you'll find that I wrote:

"You can use a fundamental mode crystal as an overtone oscillator, but
even if you can get it to oscillate, it won't be generating an
overtone at 100MHz, since overtone modes of oscillation aren't
harmonically related to the fundamental."


and that you replied with:


"That is total and absolute bullpuckey."


Notice that I didn't say "near", I said "at".

If you can find fault with anything I wrote in that post, I'd
appreciate specific criticism instead of that broad brush you painted
with.

--
John Fields

 

[Joerg]

Hello John,

"You can use a fundamental mode crystal as an overtone oscillator, but
even if you can get it to oscillate, it won't be generating an
overtone at 100MHz, since overtone modes of oscillation aren't
harmonically related to the fundamental."

When you look at older (pre-PLL) VHF communication gear of the more
professional kind they didn't use 5th or higher overtones but employed
frequency multiplier stages. For good reason, one being the offset you
had mentioned. I'd never run a crystal on its umpteenth harmonic and
always designed in multiplier stages like the radio folks did. With
today's cheap logic chips that doesn't even cost much in extra parts.

and that you replied with:


"That is total and absolute bullpuckey."

Look on the bright side. Some of us, including me, didn't know the
expression "bullpuckey". I got a kick out of it.

Regards, Joerg

http://www.analogconsultants.com

 

[Tim Shoppa]

Harold Johnson wrote:

I'm currently
using a SAW at 660 MHz for the clock in a 9951 DDS.

Interesting factoid: I was looking to experiment with 100MHz
oscillators largely as a clock source for my own AD9951 experimentation
(using the AD9951's built-in PLL multiplier at 4x). I was hoping to
experiment a bit with 20 MHz crystals I already had in hand before
ordering some "real overtone" crystals cut just for me. I've been
looking at AD app note AN-419 and it's Butler oscillator, in
particular, although the clock input of the AD9951 probably has
different requirements than the AD9850 targetted in AN-419.

Does the AD9951 really work at 660MHz? I thought it was only good to
400MHz...

So far my experimenting has used the on-chip oscillator at 25MHz and
the PLL at 16x to get to 400MHz.

Actually, it's better
than my 200 MHz 7th overtone tripled to 660

We bandied about "non-harmonic" relations here but how you get from 200
to 660, I don't know.

Tim.

 

[Harold E. Johnson]

Interesting factoid: I was looking to experiment with 100MHz
oscillators largely as a clock source for my own AD9951 experimentation
(using the AD9951's built-in PLL multiplier at 4x). I was hoping to
experiment a bit with 20 MHz crystals I already had in hand before
ordering some "real overtone" crystals cut just for me. I've been
looking at AD app note AN-419 and it's Butler oscillator, in
particular, although the clock input of the AD9951 probably has
different requirements than the AD9850 targetted in AN-419.

The built-in multiplier is quite noisy and makes the 9951 run terribly hot.

Does the AD9951 really work at 660MHz? I thought it was only good to
400MHz...

Yes, if you DON'T use the on board multiplier. I've had it to 750 MHz just
to check it since I had heard of some DL's overclocking it to that
frequency. Properly heat sunk to the eval board, and without the multiplier,
it's cool as a cucumber. AD rates it only to 400 MHz but a sample of 6 units
all operate well at 660 MHz.

So far my experimenting has used the on-chip oscillator at 25MHz and
the PLL at 16x to get to 400MHz.

Actually, it's better
than my 200 MHz 7th overtone tripled to 660

We bandied about "non-harmonic" relations here but how you get from 200
to 660, I don't know.

Well, this one is a 220 MHz 7th overtone from ICL specially surface treated
for low noise and operating in a Stephensen bipolar/FET Butler. But as I
mentioned to Doug, afraid my MMIC tripler makes a bad job of the 660 output
despite a 3 pole final filter. The SAW is not near the Q of the crystal, but
the SNR is much better.

Regards

W4ZCB