In article ,
Scott Dorsey wrote:
In article ,
Geoffrey S. Mendelson wrote:
Martin Potter wrote:

The sunspot peak of 1968-69 helped a lot. The band was pretty dead
(thankfully) due to low MUF during the early 1960s.

When I said popular, I was refering to the operation within the U.S.
law (which was and is very different than the rest of the world) which
prohibits "skip" operation.

Not at all. It just mandates a certain power input to the finals.

Actually the CB regs _do_ (or at least did) prohibit 'skip' operation.
Look it up. Communication between stations more than 150 (IIRC) miles
apart is expressly forbidden.

In article ,
Jon Teske wrote:
On Wed, 14 Mar 2007 13:54:04 +0000 (UTC), (Geoffrey
S. Mendelson) wrote:

Scott Dorsey wrote:
Not at all. It just mandates a certain power input to the finals.

At one time it DID mandate something like "local communications only".
I can't remember the exact wording, so I leave it in quotes.


Note that Class D wasn't all there was. There was Class C which allowed
pulse modulation in the 26 MHz range for remote control, and Class A
citizens band which was AM in the 450 MHz range. I don't recall what
Class B was.

I had a class C and D license. The difference was ticking a box on the
application.

Geoff.

Since I never operated CB except for one short contact in my carpool
mate's car to show him how it worked, I was not intimately familiar
with CB rules. I seem to remember thought that there were regulation
which prohibited even attempting to make a contact of over 200 miles
this was one of the ways to attempt to rein in the use of powerful
(or so) even if conditions permitted this.

I can confirm the existance of 'distace' restriction. As I recall, it
is 150 mi., not 200.

I seem to remember that
amplifiers that many CBers used (of course the prohibition of the sale
of amps capable of operation in that range, including those intended
for ham use, was another FCC mandate.)

Anyone know more about that??

Note: the amps were illegal regardless, as there was a limit of watts of
power in to the final amp, and a maximum of 4 watts RF energy out.

It is worth noting that when 'skip' conditions were right, it did not
take large amounts of RF to reach long distaces. I used an '11 meter'
(but _not_ 'citizens band') rig with just under 2-1/8 watts (measured!)
RF out, and one day was asked to shut down, by a station nearly 900 miles
distant. I was _so_strong_ in their area that legal max (10 watt RF)
stations couldn't communicate at 6 blocks distance.

I don't know the licensing requirements, but I think that there is
also a frequency or frequencies at 72 MHZ available for radio control
of models in addition to 26MHz; and, 50 MHz if one is a licensed
amateur.

Anyone up on that?

"way back when", there was 2nd set of frequenceis, besides the 11m ones
for RC controls. I don't remember at this remove (roughly 30 years) just
where it was. Was not used much, gear was much more expensive.

And yes, there were some ham frequencies where RC operations were allowed.

Robert Bonomi wrote:
[snip]
"way back when", there was 2nd set of frequenceis, besides the 11m ones
for RC controls. I don't remember at this remove (roughly 30 years) just
where it was. Was not used much, gear was much more expensive.

IIRC, there was some RC at ~49MHz. ISTR some in the 72-76 MHz range as
well, but since aircraft marker beacons operate at 75 MHz, I may be
imagining.

And yes, there were some ham frequencies where RC operations were allowed.

Hams can use almost any VHF or UHF frequency for RC: in fact, some RC
competitors have obtained ham licenses just to get access to
interference-free channels and thus away from the "clothespin
competition" so often seen at meets.

William

(Filter noise from my address for direct replies)

Robert Bonomi ) writes:

"way back when", there was 2nd set of frequenceis, besides the 11m ones
for RC controls. I don't remember at this remove (roughly 30 years) just
where it was. Was not used much, gear was much more expensive.

And yes, there were some ham frequencies where RC operations were allowed.


Amateur radio invented remote controlled vehicles, certainly as a hobby.

Since amateur radio was a technical playground, and fairly open rules
to allow that, it was there when someone wanted to fly a remote controlled.
Years ago, there was a bit in QST about early work in RC airplanes, I think
it was Ross Hull (the Australian ham who moved to the US to work at the ARRL
and was never licensed in the US, and died by accidental electrocution) and
Roland Bournes.

It took no special license, since it was allowed under the rules. It
was only later, when the hobby became more popular that a need for
an RC license that didn't require a test came about, with frequencies
set aside for the purpose.

There was a whole period when people would get a ham license because
they were interested in radio controlled vehicles.

That faded with the arrival of RC licenses and frequencies.

The "frequencies" for RC in the ham bands were a combination of where
it was legal to send that sort of thing (but it wasn't specifically
about RC) and gentlemen's agreement, since one didn't really want
interference from other operators when flying an RC plane.

Michael VE2BVW

In article ,
(Geoffrey S. Mendelson) wrote:

Then they started allowing
temporary call signs ("K" your initials and your zip code) so mine would
have been at the time "KGSM19120",

When the service started up in 1959 or so, FCC issued callsigns that
began with the number of the FCC District where the licensee was, a "W"
or a "K," and 4 digits, for example, the TV shop in Detroit I worked at
as a kid had a base station callsign of something like 19W3091, and our
trucks ID'd with that call, plus Unit 1, 2, etc. I don't remember if
there was any restriction on the number of "units" that could go with a
base license. They had to scrap that callsign system as it did not
comply with ITU convention- US calls have to begin with W, K, N, AA-AL,
and not a number. This was an issue as someone apparently didn't
consider that propagation could carry CB signals across international
borders, so the ITU regs applied. The radios came with the FCC license
application form that carried a warning to not use the rig until the
license had been received. Later on, before they finally gave up on CB
entirely, the FCC issued licenses with 4 letters (properly US-prefixed)
plus 4 digits, like KBNF2675.

Chuck WV8A Detroit MI

On Sun, 25 Mar 2007 00:25:27 -0400, Chuck Reti
wrote:

In article ,
(Geoffrey S. Mendelson) wrote:

Then they started allowing
temporary call signs ("K" your initials and your zip code) so mine would
have been at the time "KGSM19120",

When the service started up in 1959 or so, FCC issued callsigns that
began with the number of the FCC District where the licensee was, a "W"
or a "K," and 4 digits, for example, the TV shop in Detroit I worked at
as a kid had a base station callsign of something like 19W3091, and our
trucks ID'd with that call, plus Unit 1, 2, etc. I don't remember if
there was any restriction on the number of "units" that could go with a
base license. They had to scrap that callsign system as it did not
comply with ITU convention- US calls have to begin with W, K, N, AA-AL,
and not a number. This was an issue as someone apparently didn't
consider that propagation could carry CB signals across international
borders, so the ITU regs applied. The radios came with the FCC license
application form that carried a warning to not use the rig until the
license had been received. Later on, before they finally gave up on CB
entirely, the FCC issued licenses with 4 letters (properly US-prefixed)
plus 4 digits, like KBNF2675.

Chuck WV8A Detroit MI

Three letter prefixes were issued after those early numeric prefixes.

I was KQA4923

Later, I was KEV4927

They didn't seem to use strict letter/numeric order...

Doug

Chuck Reti ) writes:

They had to scrap that callsign system as it did not
comply with ITU convention- US calls have to begin with W, K, N, AA-AL,
and not a number. This was an issue as someone apparently didn't
consider that propagation could carry CB signals across international
borders, so the ITU regs applied.

This is an understatement. If they'd given thought to propagation, they'd
not have allocated 27MHz to a band intended for local use.

Even with nobody working skip, when the skip was in the band got cluttered.
You couldn't avoid propagation getting those distant signals to you, and
that did not help the intended use of the band.

Michael VE2BVW

Michael Black wrote:
[snip]
If they'd given thought to propagation, they'd
not have allocated 27MHz to a band intended for local use.

Even with nobody working skip, when the skip was in the band got cluttered.
You couldn't avoid propagation getting those distant signals to you, and
that did not help the intended use of the band.

Michael VE2BVW

Michael,

I don't feel it was a question of propagation: the FCC wanted to create
an inexpensive radio service that could be used by those who could not
afford the standard "two-way" radios that were available at the time.

The problem, in a nutshell, was that tube designs for VHF and UHF were
very expensive to manufacture, tune, and repair. I think the idea with
the class C & D Citizens' Bands was to make the rigs affordable _using
the vacuum tube designs of the day_, and that meant keeping the
frequencies low. Since ham operators had an assignment at 10 meters, and
the primary user of 11 meters (Medical Diathermy) wouldn't be affected,
it probably seemed like the ideal spot: the only commercial allocations
near it were in the 30-50 MHz range, but assigning a new service there
would have meant displacing existing FM licensees, including many local
government users, who were _also_ interested in keeping their radio
costs down.

Don't forget: the class A & B Citizens' Bands had been authorized for
many years, with dismal results: since class A & B CB radios used 460
MHz, users had to pay for the same Motorola or GE or Johnson sets that
telephone, utility, taxicab, and others with deep pockets were using.

Long story short: experience had shown that the cost of UHF units was
too high a barrier for farmers and other rural users, and IMHO, _that_
was the reason for choosing 27 MHz.

YMMV.

William

(Filter noise from my address for direct replies)

Since ham operators had an assignment at 10 meters, and
the primary user of 11 meters (Medical Diathermy) wouldn't be affected,
it probably seemed like the ideal spot: the only commercial allocations
near it were in the 30-50 MHz range, but assigning a new service there
would have meant displacing existing FM licensees, including many local
government users, who were _also_ interested in keeping their radio
costs down.

I remember medical diathermy in the 50's being an important cause of
TVI. They apparently were available for home use by patients. I never
needed one so I really have no idea what they were supposed to do.
To they still exist? Have they been replaced by a different
technology?

Jon W3JT

William Warren ""w_warren_nonoise\"@comcast(William Warren).net" wrote:

Don't forget: the class A & B Citizens' Bands had been authorized for
many years, with dismal results: since class A & B CB radios used 460
MHz, users had to pay for the same Motorola or GE or Johnson sets that
telephone, utility, taxicab, and others with deep pockets were using.

Actually there were some cheap two-tube units out there, which used
a single device as a regenerative detector or as an oscillator, combined
with an audio amplifier tube. The performance was very poor, however.
"Vocaline" was the manufacturer that I remember.

Long story short: experience had shown that the cost of UHF units was
too high a barrier for farmers and other rural users, and IMHO, _that_
was the reason for choosing 27 MHz.

Yes.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."