Dave Heil wrote in message ...
Len Over 21 wrote:

In the case of the mixing-by-crystal-banks plus VFO (or "PTO" for
most Collins radios), there was a dependency on the quartz
crystals being correct.

"Waist deep in the Big Muddy, and the big fool says to push on"..

Those were typically in the 30 to 50 PPM
(plus-minus) accuracy by themselves. That was GOOD accuracy
for the 50s to 60s time frame...but one band might be off on the
low side while another band might be off on the high side.

That "off on the low side while another band might be off on the high
side" stuff might be correct if not for the individual band trimmers
featured in all such equipment.

Yep.

Now consider how much error we're talking about. Some rigs used
heterodyne xtals as high as ~40 MHz on 10 meters. .005% works out to
2000 Hz on a 40 MHz xtal *before correction*. So the worst case could
be a total variation of maybe 4 kHz if one was high and another low -
on 10 meters. On the lower bands the error is less.

But all this is pretty meaningless because even the lower-priced rigs
have built-in calibrators and VFO/PTO calibration adjustment (usually
a dial pointer adjustment). The Heath SB-line, which isn't topshelf
stuff by any stretch of the imagination, had builtin calibrators, a
linear VFO and dial adjustment. In the early 1960s, at a price far
below Collins or Drake.

The digital-dial rigs like the TT Orion D and Corsair avoided the
problem by using a built-in custom frequency counter to actually count
the various oscillators. IIRC, this concept first appeared
commercially in the amateur market in the DG-5 accessory to the
TS-520S.

R.L. Drake and Ten-Tec also used PTOs
in their equipment.

Good units, too. A bit fast on the tuning rate, but good units
nonetheless.

With TCXOs or VTCXOs (Temperature Compensated Crystal
Oscillators, fixed or Voltage-controlled), the drift on modern
"all band" (HF that is) transceivers can be within 1 PPM after
calibration. The old Collins "PTO" (Permeability Tuned
Oscillator) achieved stability of 50 to 100 PPM over a full
military temperature environment (-55 C to +85 C) but they
were not inexpensive. Collins amateur equipment was often
at the top of the money line when they were marketing for
the hams.

Ten-Tec and Drake equipment achieved similar accuracy and were sold at
much lower prices than comparable Collins gear.

Collins amateur gear was much less expensive than commercial or
military equipment of the same vintage, and more suited to typical
amateur use. Most hams are not going to be using their equipment at
+85 C or -55 C.

Besides, "real hams" don't use any FM on HF...they hardly
ever go above 30 MHz. :-)

Is this just another things you've heard from someone else, Leonard?
While I use 2m FM, most of my operation on 6m, 2m and 70cm is on SSB or
CW. I have the latitude to choose a band I like and to operate there.
I can do this from my home or from my car.

There's also quite a bit of FM in use by hams on 10 meters. Plus FSK
is a form of FM...

The subject has gotten out of hand in here with all the PCTA
extras eager to beat on any NCTA by taking a phrase out of
logical context. :-)

It surely does get out of hand but not because of anything being taken
out of "logical context". It happened because you spouted off about
something you weren't up on. You compounded things by not admitting to
your lack of knowledge. You tried to fine tune your original statements
and were snagged yet again.

Let's take a look at those phrases:

From 2004-09-22 20:47:30 PST


LHA: "All those subbands are simply for "staking out territory." "

They were actually about creating an incentive to learn more theory
without losing access to a band or mode.

LHA: "None of that elaborate U.S. subdivision would be possible
without the modern frequency synthesizers that were NOT developed for
amateur radio but adopted for that particular market."

Repeatedly proven to be incorrect, in error, and without any basis in
fact. Hams then and now are able to stay within their bands and
subbands without any need for "modern frequency synthesizers".

LHA: "I doubt that even the most ivy-decorated in here could explain
how to make a PLL subsystem that achieves 10 Hz resolution using 10
KHz references for their PFD. I wouldn't even bother asking them if
they knew how a DDS works... :-)"

It is not clear to whom Len refers as "ivy-decorated in here". If he
is referring to me (Jim, N2EY), he's completely wrong, because I could
explain both PLL and DDS designs at length and in detail.

Those all have expensive ready-builts in
their "shack" and - naturally - those rigs are the closest thing
to perfection as anything.

Jim's isn't ready built.

Neither HF rig in current use at N2EY is expensive or "ready built".
But they work, are on the air regularly, meet FCC regulations, and do
their jobs well.

So what's the problem?

I can explain how they work in detail. I'll even draw you schematics
of the Southgate Type 7 from memory. (It ain't simple, either). Amazes
shack visitors of all ages and levels of technical ability.

Just my particular brand of fun in ham radio.

What's wrong with any of that?

The K2 has a single-loop PLL LO that achieves very low phase noise by
an ingenious design. This design intentionally trades off some
accuracy and general coverage reception in order to improve phase
noise, simplicity and power consumption. Its performance against
"ready built" transceivers costing much more is well documented.

It wasn't designed by Len. I doubt very much he understands how it
works, nor could he explain it....;-)

Mine is. They're both as close to perfection
as anything.

Which is to say, none of them are perfect!

Len's errors here prove he's not perfect either...

Why would that bother you?

The fact that we amateurs are actually designing, building and using
rigs on the air seems to bother Len no end. The fact that we are using
equipment, modes and technologies he has not personally blessed seems
to bother him even more.

They don't seem to know squat
about the inner technology involved in frequency synthesizers
so they want to "get even" with anyone who does. Sigh.

"Tney" seemed to know enough to chew you up and spit you out on your
synthesizer spur and phase noise gaffes. You'd better bring yourself
up to date, old fellow.

Not chewing up or spitting out anybody, Dave. Just pointing out a few
errors of Len's. He makes it easy, really.

Recall the original claims that started all of this, and how Len keeps
trying to avoid admitting his mistakes:

"All those subbands are simply for "staking out territory." "

"None of that elaborate U.S. subdivision would be possible without the
modern frequency synthesizers that were NOT developed for amateur
radio but adopted for that particular market."

"I doubt that even the most ivy-decorated in here could explain how to
make a PLL subsystem that achieves 10 Hz resolution using 10 KHz
references for their PFD. I wouldn't even bother asking them if they
knew how a DDS works... :-)"


73 de Jim, N2EY