[ARC5] RE: HF operation post WWII

[Telegrapher@QWEST.net]

Adding to the comments Dave made about HF operations, the ARC-2 was
used into the 70's in Vietnam.  I removed a bunch of them from
supposedly
"vietnamese" marine helicopters.  Other stuff in them was VHF and some
FM stuff
which judging from the fiberglas antennas in the 30-50 mc range.  P2
patrol aircraft as well as the marine/navy R4-D? version of the C-47
carried the ARR-41 receiver which kinda looked like a small lightweight
R-390.  HF is still used today amongst all the military forces although
none of it is AM.  I do find a BC-453 receiver tucked away in some of
the airplanes i'm cleaning out.   I fly with a Lt. Col. (retired) in his
Cessna which still has an operable LF beacon receiver.  With TWEEBS and
airport beacons still operating, Chandler Muni. for example, was just a
CW beacon a few years back. Then it went to automated voice over CW and
now its just CW again.  Doesn't appear to be a big rush into taking
these
systems down.  Not that i'm pushing their demise but just curious what
the reasoning is for them to continue operation.  I was told by an FAA
tech about 10 years ago that they were starting to turn down the last of
them.  However i haven't seen a decrease in the number of them i was
able to hear at that time.  Maybe someone in the headshed has an
answer.  As far as i'm concerned they can leave them running forever.
Love dx'ing them and dreaming of the memories they must generate for the
older than me generation who used them for navigation.

I also have charts and airfield information from the US and Pacific
regions from the WWII era showing HF, LF, RAdar and other navigational
data.  Don't seem to find anything though concerning the European
theatre.  Dave evidently has a far better collection of data concerning
HF/MF/LF operations than i do.

Larry
W0OGH


David Stinson wrote:

> (from the MilCollector Group Post)
> > To a small degree the use of the 300kc band for air traffic control
> > still survived into the early days of WW-II but only because of some

> > antiquated equipment that still existed in the system.
>
> It is commonly believed that aircraft communication on
> HF and Longwave were completely abandoned early in WW-2.
> This is a myth.
> HF was, in fact, extensively used even into the Korean conflict.
> Commercial and military towers guarded HF frequencies well
> into the 1950s.  Towers broadcasting on longwave and listening
> on either HF or VHF also survived into the early 1950s.
> While the transition to VHF primary frequencies
> was well along by 1945, aircraft equipment
> designed to receive the tower on Longwave or HF
> were still being commercially made, sold
> and installed long after the end of WWII.
> Aircraft sectionals and military radio facility charts
> from 1945 show that, while VHF was installed at most
> airports (not nearly all), HF was still very active
> and was the primary communication band
> for a large percentage of these stations.
> This was especially true in the Pacific and Asia areas,
> where coordination with the Brits was not a large issue.
> I have photographs of Pacific towers in the 1944-1945
> time frame using HF as primary communications,
> L-5 and other spotter aircraft equipped with RCA HF
> and SCR-274N in 1945 and even a Mustang P-51D from
> the early Korean conflict with SCR-274N installed.
>
> Moreover, in the cases of SCR-274N and AN/ARC-5,
> it begs credulity that extensive and expensive
> training, repair, overhaul and spare parts operations
> were maintained from 1940 until the mid 1950s-
> over a decade- for a system that "was never used."
> There have been unused systems for which training and
> support dollars were expended, but not over a period
> of 15-20 years.
> HF installations where specified in Navy aircraft
> even longer then in USAAF/USAF installations.
> These people had budgets- they didn't spend money every year
> for over a decade and a half on systems that "were never used."
>
> I've been asked from where this myth came.
> There are a few old stories floating around about
> radio techs who said this wasn't used or this didn't work.
> You could find dumb installations and badly trained techs
> if you looked for them- and some people did for reasons
> that will become clear below.
> But the fact that HF *did* work is outlined above.
>
> I haven't found enough data yet to draw a firm conclusion
> about the origin of this myth,
> but I do have enough for a working theory.
> The short version- Propaganda.
> Many proponents of aircraft VHF (with various agendas)
> collected and disseminated negative stories about aircraft HF
> in order to "speed along" the conversion to VHF.
> That propaganda lives on in the "HF wasn't used" myth.
>
> 73 Dave S. AB5S