RadioBanter - View Single Post

October 2nd 04, 04:35 PM

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

. . . some of those "works of art" before I dumstered all that
old crap. I have a yen now to build a couple more widgets using
homebrewed PCBs but so far I have not been able to find the board
stock or chemicals in hobby quantities.

Go to FAR Circuits for a huge collection of PCBs available for
all those magazine article projects. Ready-made wiring. FAR
is run by a ham.

I'm aware of FAR and the boards they offer, nice stuff, quite
affordable and they can save a lot of drudgery. But I'd still like to
burn a few of my own from scratch just for the helluvait.

Don't keep old "crap." Save that to toss at NCTAs in
newsgroups.

snore

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.

I fed the aformentioned dumpster a *shoebox* full of those old 7400
series chips . . .

Tsk. Well, if you don't know how to use them, toss 'em.

Nah. Just about everything radio in that heap which was more than
twenty years old landed in the dumpster on general principles.

You are PCTA extra royalty. Save the TUBES, recycle 'em into
world-beating contest-quality radios to win all those accolades!

I already gave 'em to Miccolis, ALL of 'em. 'Cept for the NOS Eimac
3-500Z. I'll prolly make a lamp out of it.

That leaves Sweetums and his half-vast "experience" out. Long-haul
military HF comms are channelized and if a station is weak they just
twist the Variac clockwise. 40kW with rhombics just to push RTTY from
Tokyo to the west coast . . SPARE me . . !

You "know" all about military communications?

Absolutely not. Nor do I give a rat's patooie about military comms
gear.

Of course you do.
You were of the royalty that was never IN.

Right again.

You've never worn an AN/PRC-104 HF manpack raddio, have you?

Have you?

Big, powerful 20 W out on HF, operational with U.S. land forces
now. Same RF power out as the SGC 2020 being made in Belleview,
WA, by the company started by Don Stoner and Pierre Goral (both
SK, sadly, long-time hams).

The full manual for the 2020 is on the SGC website in case you
wanted to find out what is done TODAY. I could tell you were to
get the four full government manuals for the PRC-104 free but you
will only tell me "where to go." :-)

I hate to bust yer bubble again Sweetums but they're all over the ham
bands used mostly by the "pack radio" crowd. Nice rugged little
minimalist's xcvr but somewhat lacking in rcvr basic performance.

The "4 KW" and (later) "40 KW" pushing from Tokyo to San Fran or
anywhere else in ACAN was for SIDEBAND. The 12 KHz first
variety of SSB carrying four voice-bandwidth circuits. If you wanted
24/7 communications on HF back a half century ago, you needed
power and antennas. You spit on that fact, relegating such "menial"
tasks to "drudges" while you brag about "eating at the captain's
table."

"Here ya are Gunther, go for it boy!"

It's no big deal at all. As far as the "math" goes any kid who has a
decent grip on 9th grade alegebra can hoof thru it, this is not double
integral or tensor analysis country. All one needs to pull it together
is the material physical properties and the ability to jiggle a few
simple algebraic equations which are only a half-step beyond jiggling
Ohm's Law. All of it is readily available out on the Web and it can
all be done with a pencil and a calculator.

That's why Phil Smith came up with the Smith Chart back before
WW2. :-)

Not for designing antennas...for easing the work required by
Bell Telephone on long-distance transmission lines. Work that
required slide-rules and mechanical desk calculators (sometimes)
due to pocket calculators not being invented yet. :-)

I'm not new to slide rules and Fridens Sweetie, I had one of each on
my board back when I was designing catapults.

For my own part I've gotten into semi-automating the whole process in
order to design widgets like tapered aluminum yagi elememts,
fiberglass quad (squalo?) spreaders, masts and towers. I run a LISP
rountine in Autocad to come up with the cross-sectional properties
then diddle the rest in Excel or Mathcad or a slick little $50
shareware program called "DTbeam" which is a finite elememt analysis
beam analyzer. The M.E.'s version of a Java-based Smith Chart solver.
Sort of.

Tsk. You should use Roy Lewallen's EZNEC. Roy is a long-time
ham. EZNEC is advertised in QST.

Sweetums if you will kindly point out just where in EZNEC Roy provides
the ability to work thru antenna stress and deflection issues.

USN Postgraduate School folks came up with the Numerical
Electromagnetic Code (NEC) which is all free to anyone (no
copyright).

I'm not new to NEC either Sweetums, I have NEC2 two mouse clicks away
from here along with it's Nec Win Plus interface.

Too bad the USN types at the "captain's table"
didn't mention that to you...

.. . . in 1963??