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September 30th 04, 10:57 PM

In article ,
(N2EY) writes:

(Brian Kelly) wrote in message
.com...
PAMNO (N2EY) wrote in message
...
In article ,

(Brian Kelly) writes:
(Len Over 21) wrote in message
...
In article ,

(Brian Kelly) writes:
. . . . . . .
What you *did* claim was that you could operate within 200 Hz of a band
edge
and know you were inside, using certain '50s/60s vintage equipment. Which

is a reasonable claim for the equipment involved.

btw, back in 1975 or so I designed and built a "digital dial". The way it
worked was that it used TTL 74192 presettable up-down counters to count
the
tunable oscillator. You'd adjust dip switches for the offset and
direction of
each band and mode. Its time base was a 400 kHz xtal, easily zeroed to
within a
few Hz of WWV. The thing normally read out in 100 Hz increments but could
be
switched to 10 Hz or 1 Hz. Its accuracy was dependent on how well you set

the
time base and presets. Could be used with almost any rig. Hooked it up to
a
75S3 and got an A in the course.

Lab course at Penn?

Independent design project. Made the circuit boards meself and all.
Still have it, still works. Don't use it much though, because one
thing I learned in the process was that I prefer an analog dial for
most purposes. Just a personal preference. Which is one of the big
reasons to homebrew - you get to indulge personal preferences.

The "160" and "190" series ICs appeared some time prior to
1973 since their full data is included in the hard-bound Texas
Instruments "The TTL Data Book" that I have from RCA days
(courtesy of distributor R.V. Weatherford).

There were a number of applications notes by several semi-
conductor makers on various ways to use those two families
of 8 separate function types. I admit to not retaining many of
those...most went to paper recycling long ago. Memory serves
that several frequency counters, including up-down counting
types did appear back then.

The even numbered ones of the 8 were decade counters, the
odd numbered ones 4-bit binary (maximum 16 count). The
decade counter types are now either dropped from production
(Philips, Fairchild) or marked "not for new designs" (ON Semi,
ST). That includes all the upgraded performance families such
as 74LS, 74S, 74ALS, 74AC, 74ACT, 74F, 74HC, 74HCT.
The only up-down counters available for decade counting now
are either surplus stock at a few vendors or in old, slow CD4000
series maxiing at about 4 MHz tops at 5 VDC.

To do top-of-the-HF band programmable dividers for a PLL today
requires the 4-bit binary '191 which can safely count to about
45 MHz with a 74AC191 and using the terminal count gated with
clock pulse low state as the assynchronous parallel load for
presets carrying the divider control input. Preset input has to be
binary so any conversion from BCD has to be separate (either
hardware with slow-speed adders or through an embedded micro-
controller).

If all that is wanted is digital readout from an existing analog
frequency control subsystem, the microcontroller-based frequency
meter marketed by AADE can't be beat...and Neil offers a TCXO
crystal option for absolute minimum drift (both can be "beat" with
WWV). The microcontroller itself (a 16F71 from Microchip's PIC
series) is the counter (up to 40 MHz maximum) and the internal
PIC programming handles the conversion from binary to decimal
plus the translation to ASCII and scanning for an LCD readout.
Ingenious way of making a frequency meter without any separate
IC counter packages...devised by a non-ham Brit about 10 years
ago.

The 74192 and other TTL family chips were hot stuff 30 years ago when
I was doing that project. You can still get pin-compatible parts
today.

At best, without going to the surplus stock vendors (one is located
in Beverly Hills, CA, of all places), Jameco offers the 74HC192 and
74HC193 at reasonable prices. Unknown how long that will last
since the 74HC192 is not in production.

"30 years ago" would make it 1974. At that time there were a
number of application notes on counter uses. "pre-design"
designs that anyone could copy.

The '192 and '193 have the distinguishing characteristic of separate
up/down count inputs and separate up/down terminal count outputs.
Made it convenient for the input (least-significant bit or decade) from
different count sources. The bad part was that the TC (Terminal
Count) was active on the clock pulse low state; that does not offer
a long enough recovery time prior to the next positive-going clock
edge to do high-rate programmable counting. Programmable up-
down dividers of higher rates should use the '190 or '191.

All of that is important when there's a "recyclable update" for that
"impressive to all visitors" Southgate Type 7 with "inventions" of
adding semiconductor IC technology.

Hello? Something about "not re-inventing the wheel?" :-)

The audiophile *market* is full of pseudotechnology - driven by the
fact that there's $$ involved. But there's also some good stuff too,
driven by folks who like *music*.

I like music.

Tsk. Why do you insist that all test their musicology by testing
for monotonic, aperiodic beeps that are a representation of the
written word?

I've run into more than a few hams who say they "hate contests because
they make the bands so noisy". What's really going on, in at least
some cases, is that the effects of so many strong signals on the air
all at once raise the apparent noise floor of their *modern*
transceivers, in part due to phase-noisy oscillators in the
contest-haters equipment.

So...you hate the contest haters all on account of "phase noise?"

Tsk. You ought to get used to the fact that not everyone likes
contests for the simple reason that they are contests, organized
by contestant-wannabes so that they can Win and show off that
they are "better" than the non-contestants. :-)

One of the problems with older solidstate equipment is that much of it
used custom parts for which the only sources are the manufacturer (if
they still support the unit) or junker units. If there was a weak
spot, finding a junker with a usable part maybe hopeless. The Kenwood
TS-440s reputedly has this problem in its display.

So...you think vacuum tubes will be with you always? :-)

Of course...you can "recycle" them...somewhat after their useful
life...and "impress all who visit your shack."

Tsk.