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September 28th 04, 12:38 AM

In article ,
(Brian the Bluffman's Home Companion Kelly) writes:

(Len Over 21) wrote in message
...
In article ,

(always write even when wrong) writes:

In article ,

(Brian Kelly) writes:

Whatever you say. You can imagine getting within 10 Hz of the
correct frequency with the '50s designs all you want...but that
won't make it happen.

What?? Where, exactly, has anybody claimed 10Hz frequency resolution
with '50s analog radios?

As you will say later, those "analog" radios have INFINITE resolution. :-)

Creative PLL and DDS subsystems of today, designed by others,
make it possible for anyone to select 10 Hz increments on any
HF band (30,000 frequencies within 300 KHz) with crystal-
controlled accuracy.

Analog VFOs are continuously variable. Making it possible for anyone
to select an *infinite* number of "increments" within a 300Hz
bandwidth much less your coarse 300 Khz wide example.

Heh heh heh...your bafflegab won't win blind man's bluff, Kellie,
deal yourself a better hand... :-)

Feel free to try to state you can return to that "infinite possible"
setting within a few PPM...all without any old crystal calibrator and
dependent on that "coarse" analog dial. :-)

And they do it
without generating any phase noise or other forms of crud synthesizers
toss out.

Kellie, define "phase noise" insofar as amateur radio operation is
concerned. You, for the limits of your technical knowledge, should
call that "incidental FM" which is what the industry term "phase
noise" refers. :-)

Then you should examine exactly how low that terrible phase noise
is. You can use the term "dbc" referring to the number of decibels
below the "carrier" (center frequency reference, not a modulated
carrier per se). The "crud" (as you term it) is quite far down in
relative power and certainly won't affect morse code reception of an
on-off keyed station's carrier.

"Phase noise" is a somewhat new buzzword in industry due to the
importance of keeping it low for QAM signals (Quadrature [phase]
Amplitude Modulation, a combination of PM and AM). The cell
phone engineers will know of that importance on keeping the BER
(Bit Error Rate) as low as possible. The amount of work in the last
decade on cellular telephony techniques has been enormous
worldwide. It's only natural that industry advertisements, from sub-
system components to full systems, emphasize a low "phase noise."

As far as on-off keyed radiotelegraphy, your mention of "phase noise"
as being "crud" in synthesizer frequency control is akin to making
a big case for gold-plated music system speaker wires. :-)

It is ignorance to discount the possibility of "crud" being non-existant
in analog mixing frequency generators. Those analog "infinitely-
variable" oscillators are just as prone as anything to "phase noise."
The wrong selection of mixing frequencies will produce spurious
responses...one of the papers I wrote at RCA was on quick
identification of such possible spurs (not the first, but it was a
very quick way to determine them).

My FT-847, which is not much as ham xcvrs go, can be tuned in 1 Hz
increments vs. the "make it possible for anyone to select 10 Hz
increments" thingey you cite above.

10 Hz increments is common in installed equipment (including the
ham consumer market) in the past two decades. I know there are
smaller increments...:-)...but I also have to play to the common
denominator of technical expertise in here.

10 Hz increments are perfectly fine for SSB voice tuning, as I've
found out with my Icom R-70. If I need to get closer than that
(don't know why I should), the RIT will handle those "infinite
frequency" things. :-)

When I bought my R-70 (years ago), the three extras at work in the
Van Nuys, CA, store didn't know squat how Icom was able to do it
with 10 KHz reference frequencies to the PFDs (factor of 1000:1)
there. Turns out Icom has a neat 3-loop PLL arrangment, doesn't
go into DDS or Fractional-N at all. Minimal phase noise and no
discernable "crud" anywhere within full tuning range.

Okay, so your spiffy-schmiffy 1 Hz resolution "xcver" is "guarnateed"
accurate because it has a "digital dial?" I don't think so. Exact 1 Hz
settings imply 100 PPB (Parts Per Billion) accuracy of the master
reference oscillator. You will NOT be able to hold such accuracy
and be believable to anyone who has worked to such accuracies in
crystal oscillators. Certainly not for the ham consumer market.

Fella named John R. Vig (unusual surname) is a good name to
remember on what can be done and can't be done with crystal
oscillators. Big name in the frequency control part of electronics
industry, probably not in the pages of QST. :-)

You obviously need to spend
considerable time leafing thru the ham catalogs to get up to speed on
the equipment we use before you spout off and continue to goose up
your "coefficient of ignornace" on the subject of ham radio in general
and the equipment we use. Again. Gets boring.

True. I never bothered to memorize advertisements in QST by
heart...like so many PCTA extras do. :-)

I rather prefer what I've been exposed to since 1963 on frequency
control methods...beginning with those "cruddy" synthesizers
(without "real" frequencies, only the "synthetic" variety)...and
quartz crystal oscillator accuracy and stability to the 10 PPB
region.

Common ham radio quartz crystals have guaranteed accuracies
to 50 PPM typical. That translates to 500 Hz at 10 MHz, by way
of example. 1 Hz accuracy at 10 MHz is 100 PPB, or 500 times
closer.

Then there are the few "drudges" (like myself) who've
gotten our hands dirty doing the design and testing of synthesizers.

Then there are drudges like me who have ham licenses and and put
technoligies to work on the airwaves whilst all you're allowed to do
is bafflegab about 'em with your keyboard.

I'm sorry that my technical competence seems like "bafflegab"
to you. Some further learning of the radio technical arts would
erase some of your ignorance and lend credence to what I've
said. Like, I could ask you "how's the zeta of your control loop"
and you would be out to lunch, cussing and hollering "bafflegab!"
"Zeta" is the symbol for the response characteristic in a closed
loop of a PLL, Fractional-N, or hybrid PLL-DDS system. An
important factor for lock-in and stability and anyone designing
the loop filter for a synthesizer should recognize that common
term.

I've never dined in the executive dining room (the counterpart to
your "captain's table" BS) in any electronic corporation but I
HAVE designed and made frequency synthesizers. Hands-on
work all the way, from the initial paper work-up to long hours
in the environmental lab...to accuracies in 100 PPB over
full military environment. Interesting, challenging work!

USING modern equipment is NOT involving development or
anything else. Try not to run off at the mouth/keyboard so
hastily. Try not to nit-pick like nits over minor phrases in
postings so that you have an "excuse" to cuss and snarl at
NCTAs. It makes you look like nursie's cousin. :-)

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