From: on Dec 18, 3:57 pm

wrote:
Dave Heil wrote:
wrote:
From: Dee Flint on Dec 15, 3:21 pm
"Bill Sohl" wrote in message

Actually the place that I see the difference in operating skills is on the
VHF bands in the VHF contests. When I review my contacts in those contests,
the large majority of them are Extra class operators. They seem to be the
ones to have the skill necessary to put together and operate a station
suitable to make long distance VHF contacts and the skill to do so.

Wow! Someone should have TOLD the U.S. Army Signal Corps folks
at Evans Signal Laboratory in 1946 when they were the first to
bounce a radio signal off the moon!

How much power was used by the Army?

The transmitter used was a modified SCR-271 radar unit. It produced
3000 W on 111.5 Mc. (that's what the Signal Corps called them
back then). Pair of 6C21 triodes in the output - they look similar to
1000Ts.

3000 W output with those tubes at that frequency means about 5000 W
input.
The amateur power limit back then was 1000 W input.

Was RADAR a legal mode? What was the PRF?

RADAR is an acronym for RADIO Direction And Ranging.

Radar was perfectly legal for the DoD to use. The FCC has
no governance on the government radio energy use.

"PRF?" With an echo return delay of 2 1/2 seconds, isn't
much good for lively back-and-forth anything. 0.3 Hz
PRF could be used. :-)

The USN put it to use in communications first, simplex only
with, I think, RTTY. I'll have to find the excellent USN
paper "From The Sea To The Stars" history somewhere on an
archive CD here. Has the history of the USN involvement
in space and communications thereto, from an official USN
website.



There's a lot more info at:

http://www.campevans.com/diana.html

Jimmie is nostalgic over experiments done 59 years ago.

He wasn't there but he was there.


btw, it was a moon RADAR experiment, not a communications system.

Tsk, Jimmie thinks "communications systems" arrive full-blown,
fully-proven? :-)

Project Diana was an EXPERIMENT to test whether or not the
moon could be used as a radio wave reflector. It was and
what followed were more experiments by many to determine
what the frequency ranges were, the reflection characteristics.

There wasn't any need to "radar" the moon. The moon's orbit
has been accurately known for years, if not centuries. We
can all make certain of where it is. No radar needed for that.

The mode used was OOK CW. The echoes were heard as beeps.

Really? :-)

Civilian at Fort Monmouth Signal Labs told us it was
first observed on an oscilloscope, one of the long-
persistence phosphor types used in some radars then.
Of course that was told to us in 1952 AT Fort Monmouth
by one of the experimenters. Since he didn't give a
ham call sign Jimmie would suspect him of lying. :-)

1952 was only 6 years after Project Diana. The
experiment was fresh in his mind and, having been
there as part of it, could recall much.


Those Diana folks had a some hams involved, though - all code tested at
at least 13 wpm:

Conditionals or FCC tested?

Uh huh, like Coles, Evans, and Squier laboratories was
busy, busy on ham radio research in 1946? :-)

In reality, the 1945-1950 time was one of transition from
a world war effort to peacetime and lots of the movers
and shakers in technology-intense war efforts were out to
carve new niches for themselves and their groups. Good PR
was the word of the day. A "moon bounce" thing was hot PR
at the time, attracted attention from the budget-keepers
in Congress and the Pentagon.



Those are just the hams I know of that were involved. There were
probably more.

There always are.

...and Jimmie "knows" them. :-)


They used power levels 9 dB above those permitted to amateurs at the
time, and
an antenna that was quite beyond "backyard construction". They had lots
of resources.

A fantastic use of post-war resources.

That "111 Megacycle" radar was already surplus before WW2 ended.
Not a problem. :-)

Anyone riding a bus to Red Bank from Fort Monmouth could look
out and see lots and lots of "junk" at two of the labs along
the highway in 1952, just 6 years after the Diana success. All
sorts of "bedspring" antenna structures were sitting in the
vehicle parking areas.

Lt. Col. DeWitt, W4ERI, was the driving force behind the whole idea,
which he first began working on in 1940.

What idea? To bounce a signal off of the moon for no communications
purpose?

In 1940 that ancient Project Diana radar set (the
original, not the kludge version used IN Diana) was
still undergoing operational testing. Even then it was
a late-comer using rather conventional vacuum tubes in the
usual ring-oscillator circuit...the style of transmitter
used by the Brits for radar along the channel.

The Brits would come up with the magnetron to make microwave
radars the future practical success. We would incorporate
those in all the later radars at S, C, and X bands during
WW2. The "star" of Army radar was the semi-trailer size
SCR-584 gun-laying radar set which was definitely well above
VHF in frequency range. Those were far from "surplus" in
1946. Monmouth had a couple for radar school practice in
1952. :-)

Isn't that like bouncing a basketball off of a backboard with no
intention of making a basket?

Jimmie "Knows" what was intended, deep in his heart. He "felt"
it 59 years ago.

The concept of reflection of radio waves was well known in
basic radio physics in the 1940s. What was lacking was
some definite information on the characteristics of
radio wave reflection. Nobody had any CONFIRMED idea of
the reflectivity of the lunar surface in the 1940s.



... During WWII, the Signal Corps used the ARRL
Handbook, Leonard. I'll bet that chafes you to no end.

I really don't think so, having known a lot of USA, USN,
and Air Corps vets who trained during WW2. Some of them
said they used a USN basic book. Nobody mentioned
any "ARRL books." shrug

A 2-hour lab class one afternoon had us examine a bunch
of "basic hardware" of radio. One item was a two-tube
MOPA style HF transmitter. That MIGHT have been made
from a ham design although it didn't tune into ham bands
that existed then (instructor told us so, monitored on
an old Hammarlund receiver). We didn't take notes. In
fact, written notes were discouraged. Not for "secrecy,"
but for the need to have it in the head, much more useful
in the field which didn't allow for notebooks or stacks
of magazines for reference which could get rather wet.

In 1952 at the Signal School in Fort Monmouth we (at
least in radar basic classes) used training films on
basic principles and Army FMs, TMs for paper study,
some mock-up training aids that included a "block of
frozen RF" (acrylic plastic 3-D waveguide fields and
waves, roughly the size of 1 GHz guide). I'm not
acquainted with what was used at the Field Radio
and Telephone schools at Camp Gordon (now a Fort) used.
Monmouth in 1952 was basically for radar training with
advanced schools for the VHF, UHF, and microwave radio
relay sets...and photography, then a part of the Signal
organizational envelope (photography is now under the
media graphics specialty groups, not part of SigC).

As I remember the old ARRL handbook from the late 1940s,
I can't recall a heckuva lot of multivibrators or radar
or microwave information, nor of servo motors (but there
was a mention of Selsyns, surplus for beam indication).
Perhaps the ARRL had to exorcise all that "wartime
literature" because of "secrecy?" :-)


[unsigned message, under wraps due to Title 18 U.S.C.]