[CW] How Old is the Closing "Dit Dit" on closing ham radio contacts?

[D.J.J. Ring, Jr.]

How old is the "dit dit" you hear on ham radio when stations sign with each
other?

Some say the "dit dit" came from "shave and a hair cut" but it didn't the
roots of this went way back in radio history.

The "dit dit" was in commercial radiotelegraphy usage in the 1930s
according to my friend Bob Shrader, W6BNB who worked for "Dollar Lines"
passenger liners in the 1930s and later taught radio at U.S. Merchant
Marine Academy at Kings Point, NY.   I had asked him when this started and
he said it was common as a handing off when signaling for a frequency shift
after calling on 600 meters.

Such an exchange would be like this - going back to stations that were
active in the 1940s.

WSL WSL WSL DE WIEA WIEA  WIEA  K     (Steamship "Manhattan/WIEA" is
calling Amagansett, Long Island, NY Radio (Mackay Radio) on 500 kc/s (kHz)
(600 meters).
WIEA DE WSL R UP 640/633 K                     (Mackay Radio Amagansett,
Long Island answers telling Manhattan to shift UP in wave to 640 meters and
listen for WSL on 633 meters.)
Then WIEA (SS MANHATTAN) would send:
R UP =                                                           (SS
Manhattan says "Received, UP"
WSL (Amagansett Radio) would send:
=
WIEA would acknowledge WSL's sending (BT) by sending the two E's or 'dit
dit'.
dit dit
WSL would acknowedge this with a simple singular dit.

This was back when WSL was on 633 meters - or 474 kc/s (now kHz).
Coast Stations were assigned working frequencies.

WSL was assigned 633 meters / 474 kc/s.

Here are the assigned frequencies for the East Atlantic USA Coast.

Callsign  Frequency  (Wavelength)  Location                    Operating
Company
=============================================================
WAG      418              (718)              Thomaston, Maine    Mackay
Radio
WBF      436              (690)              Hingham, Mass.        Tropical
Radio
WIM      406              (740)              Chatham, Mass.
R.M.C.A. (Radio Marine Corporation of America - RCA)
WSL      474              (633)              Amagansett, L.I., NY  Mackay
Radio
WNY      442             (680)              Brooklyn, NY
R.M.C.A
WSC      462             (650)              Tuckerton, NJ
 R.M.C.A
WMH     478             (628)              Baltimore, Maryland    R.M.C.A.
NAM      464             (647)              Norfolk, Virginia
U.S. Navy
WSV      408             (735)              Savannah, Georgia     R.M.C.A
WNW     438             (685)              Phila, PA
 Tidewater Wireless Telegraph Company
WMR     418             (718)              Jupiter, Fla
Mackay Radio
WOE     394             (761)               Lake Worth, Fla          R.M.C.A
WAX      484             (620)              Hialeah, Fla.
 Tropical Radio
NAR      464             (647)              Key West, Fla.
 U.S. Navy
WPD     438             (685)              Tampa, Fla.
Privately Owned
WNU     448             (670)              New Orleans, La.
 Tropical Radio

In the 1980s to 1990s the situation would be much the same, but instead of
giving wavelengths, we now used frequency, but with one interesting quirk.

In the 1930s when Amagansett Radio / WSL told SS Manhattan to shift
wavelength from 600 meters, he said to SS Manhattan/WIEA transmit on 640m
and listen for WSL on 633m. - they sent UP because they shifted UP in
wavelength.

At some point, stations started using frequency in kilocycles per second
instead of wavelength.

So, let's give an example of one time I worked WSL Amagansett Long Island,
NY radio from WILLIAMSBURGH;/WGOA - let's see how it was different and the
same.

The ship working frequencies (for sending message traffic) in 1920s were in
kc/s (kHz) with meters in parenthesis.

400 (750), 410 (730), 425 (705), 454 (660), 468 (640), and ship and shore
calling where both ships and shore stations kept a watch 500 kc/s (600m)

So the calling frequency, 500 kc/s was the lowest wave that ships could use
on that group of frequencies, so any other frequency was ALWAYS higher in
wavelength, so it was always UP.

Here's what happened in 1980:

WSL WSL WSL DE WGOA WGOA  WGOA  K     (Steamship "Williamsburgh/WGOA" is
calling Amagansett, Long Island, NY Radio (Mackay Radio) on 500 kc/s (kHz)
(600 meters).
WGOA DE WSL R UP 425/418 K                     (Mackay Radio Amagansett,
Long Island answers telling Williamsburgh to shift UP to 425 kHz and listen
for WSL on 418 kHz.)  WSL's Frequency had changed over the years to 418 kHz.
Then WGOA (Williamsburgh) would send:
R UP =
(Williamsburgh says "Received, UP"
WSL (Amagansett Radio) would send:
=
WGOA would acknowledge WSL's sending (BT) by sending the two E's or 'dit
dit'.
dit dit

WSL would acknowledge this with a simple singular dit.

This Morse "dance" of <BT> which is = then acknowledged by - then by a dit
dit then a single dit carried on for nearly 80 years when Morse finally
ended in 1999.

The funniest thing is that stations continued to send UP when they told the
other station to shift to their working frequency!

73
DR
N1EA
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