HFU HF Underground

Loggings => 10/11 meters => Topic started by: R4002 on June 11, 2019, 1241 UTC

Title: 25835 kHz 25.835 MHz Trucking Company ? Business Comms 1100 UTC 11 June 2019
Post by: R4002 on June 11, 2019, 1241 UTC
Did some quick 11m band scanning this morning on the way to work (receiver is a Superstar 3900, older style version with Hustler IC-100 mag-mount antenna).  Noticed the usual in-band activity as well as what appeared to be semi-local two-way comms on 25.835 MHz AM (channel 19 on band A, or channel 19 down three bands on the de facto standard 6-band export frequency or channel plan).


Hearing some trucker communications / truck to truck chatter on 25835 AM this morning.  Talking about moving loads up to a meeting point or distribution point.  Two OMs with roger beeps.  No echo noted, but strong AM modulation and rapid fading up and down (indicating that they're moving). 

De facto standard 6 band export 11 meter (10 meter) radio channel plan.  Band D is the CB band (or the mid band 26.965 MHz to 27.405 MHz), Band C is the low band (26.515 MHz to 26.955 MHz), band E is the high band (27.415 MHz to 27.855 MHz).  Band B is the low-low band (26.065 MHz to 26.505 MHz) and Band A is the super-low band (25.615 MHz to 26.055 MHz).  So if the CB band is band D, channel 19 is 27.185 MHz, down one band is 26.735 MHz (band C), down two bands is 26.285 MHz (band B), down three bands is 25.835 MHz (band A).    This is the standard 6-band / 240 channel export radio channel plan.  Up one band would be 27.635 MHz (band E) and up to bands would be 28.085 MHz (band F).  One "band" is 0.450 MHz / 450 kHz.  Truckers love to flip the band switch up or down to find a clear frequency, instead of touching the channel knob, its easier to leave the channel setting where it is, and simply flip the band switch.  Because of this, the common trucker channels on the various A-B-C-D-E-F bands are popular places for AM activity during band openings.  Channel 19 is the obvious starting point, but channels 14, 15, 16, 17, 18, 20, 21, 22, 23, etc. are also popular.  I've noted trucker comms on 26.775 MHz (channel 22 down one band), 27.535 MHz (channel 11 up one band), 27.605 MHz (channel 15 up one band), but 27.615 MHz, 27.625 MHz and 27.635 MHz are all very popular (channels 17, 18 and 19 up one band).

Maybe this is the beginning of another band opening (yesterday I heard what sounded like several different business or trucking company comms on various 26 MHz frequencies in Band B (26.065 MHz to 26.505 MHz) and on the high channels (Band E), including 26.325 MHz, 26.365 MHz, 26.375 MHz, 26.405 MHz, as well as 27.585 MHz, 27.655 MHz, 27.755 MHz and 27.775 MHz, all AM mode. 
Title: Re: 25835 kHz 25.835 MHz Trucking Company ? Business Comms 1100 UTC 11 June 2019
Post by: ChrisSmolinski on June 11, 2019, 1307 UTC
Some in band activity at 1300z, 38L is fairly busy as usual, just heard a station from Daytona Beach FL. And another in GA. No activity noted above or below the CB band.
Title: Re: 25835 kHz 25.835 MHz Trucking Company ? Business Comms 1100 UTC 11 June 2019
Post by: R4002 on June 11, 2019, 1501 UTC
Seems to be almost daily band openings on 11 meters lately, at least with the legal 40 CB channels.  38 LSB / 27.385 MHz LSB is a great indicator of band openings.  When 38 LSB is hopping its a good idea to check nearby channels, especially 37 LSB and 39 LSB, as well as the in-between frequencies (namely 27.370 MHz LSB, 27.380 MHz LSB, 27.390 MHz LSB and 27.400 MHz LSB).  I've noticed that channel 40 (27.405 MHz) is almost always full of AM voice traffic during band openings, save for SSB traffic on 27.400 LSB from time to time.  27.410 MHz has been logged during previous openings too, but suffers from QRM from AM signals on 27.405/channel 40. 

When 38 LSB is hopping and the in-band AM DX channels (6, 11, 15, 26 and 28) are hopping too...check 26.915 MHz and nearby channels...I've noticed that once the band activity gets to a certain point, some operators start going out of band looking for a clear frequency.