CW on 500 KHz Series - Part 1

Copyright 1994 by Jeffrey Herman KH2PZ/KH6
All Rights Reserved.

The following seven part series has been recorded for the historical record. We are witnessing a never-to-return era of communications style and format that was so perfect that nothing will ever be its equal. I am very glad that I was able to be a part of it, if only for three years at the US Coast Guard Radio Station Honolulu, call sign NMO.


In July of 1977, as a 3rd Class Radioman Petty Officer for the U.S. Coast Guard, I received orders to report from Coast Guard Group Monterey, CA, to Coast Guard Radio Station Honolulu in Wahiawa, Hawaii. I had graduated from Radioman School a year earlier concluding 5 months of training in code, propagation, radio fundamentals, ITU procedures, and other disciplines. The minimum code speed needed to graduate was 22 words per minute; mine was 25.

Radio Honolulu, NMO, is situated on a huge plot of land owned by the Navy, centered in the pineapple fields of Oahu. In addition to NMO, the Navy and the Marine Corps had their Central Pacific Communications command based there as well. By the way, NMO has the longest overwater microwave link in the world; Oahu to the island of Kauai for VHF marine band operations. NMO was set up with the following glass-enclosed operating positions: 500 kc CW, HF CW, HF and VHF voice, air-to-ground, RTTY, Fleet Broadcast, landline TTY, and the Chief's desk. From where the Chief RM sat, he could watch all of the ops to make sure no one fell asleep; pity the poor operator (op) who was caught sleeping while on watch!

The Coast Guard is the only military service that communicates directly with the public. Thus, we had to know when to turn off the military radio jargon, particularily on 2182 kc, the MF international voice calling and distress frequency and channel 16/156.80 Mc, the international VHF voice calling and distress frequencies. The voice op was kept busy monitoring over a dozen voice channels: 2182 kc, the 4, 6, 8, 12, and 16 Mc high-seas SSB ship-to- shore freqs, four VHF repeaters for channel 16. NMO had a microwave repeater on Kauai, Oahu, Maui, and the Big Island. There were four repeaters for VHF channel 23, and whatever else the Chief felt should be monitored. Several times each radio day, the voice op had to make weather (WX) broadcasts, Notice To Mariners, etc.. on all these frequencies. The timing was critical so the clock had to be checked frequently.

The HF CW position required 2 ops using two racks each consisting of: four Collins 651S digital readout receivers scanning the CW calling bands on 4, 6, 8, 12, 16, and 22 Mc. In daytime hours, one op would take 8 and 12 Mcs - the other operator would take 16 and 22 Mcs; at night time, one operated 4 and 6 Mcs - the other would have 8 and 12 Mcs. So, an operator might have 8 Mc scanning in his left ear and 12 Mc scanning in his right since the receivers automatically scanned a preset band of frequencies. For example, the 8 Mc calling band for ships calling shore stations runs from 8360.4 to 8374 kcs.

A ship calling us might have to send our callsign 20 to 30 times (no 3 by 3 format here!) while our receiver scanned. The NMO op would then hear, from the highest to lowest to highest notes possible (within 1 to 2 seconds) of our callsign being sent; he would quickly shut off the scanner, tune in the ship and turn off our CQ tape. When no traffic was being passed, we would keep the transmitters busy sending:

CQ CQ CQ DE NMO NMO NMO QRU QRU IMI OBS AMVER QSS 4 6 8 12 16 22 MHZ AR - (sort of an advertisement for traffic), and the exchange might go some thing like this:

That meant the ship has a weather observation. (Every 6 hours starting at 0000Z every ship worldwide takes an OBS and passes it, at no charge, to the closest shore station). This ship wants me to listen for him on 8360 kc; he'll continue to listen to me on NMO's fixed transmitter frequency. Notice the signal 'UP'. This means: `I'm shifting up to that freq'. Any exchange ALWAYS ends with `dit dit' (and hams thought they invented that!).

Having one ship calling in at a time was rare. During the OBS hour, not one ship would call, but dozens and dozens would be calling. All of this traffic was monitored with both ears and the receivers scanning! The NMO operator would have to line them up numerically:

R 8360 TU
R 12561 TKS
DE 7XYM 8370 R UP
OK UP 8375 TU
Then, the op would copy the WX OBS from each ship one by one. After working that group of 25 ships he'd turn on the CQ tape again and scanners, and dozens more ships would pounce on him. Since WX is time-sensitive, it was a race to `collect' as many OBS as humanly possible. A lazy op might only get 100 during a 30 to 45 minute period.

End of Part 1.

Click here for Part 2