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Author Topic: The taxis are back (26-28 MHz)  (Read 1371 times)

Offline R4002

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The taxis are back (26-28 MHz)
« on: October 20, 2015, 2146 UTC »
With the band opening up today, and the UK coming in nicely earlier (around 1600-1700 UTC), I decided to do some loggings:

Now that its around 2130 UTC, the European stations have disappeared and the Latin Americans dominate the 25-30 world.  I am fascinated by the heavy use the taxicab/trucking industries make use of these frequencies, especially in Spanish-speaking countries.

Here's some logs.  I must note that I can hear WWV on 25000 nearly 30dB over S9 :D

All are in Spanish unless noted otherwise.

25615 AM - Taxi Dispatch (this is channel 1 on band A on most export radios)
25645 AM - Taxi Dispatch
25775 AM - Taxi Dispatch, other AM voice traffic, noise toys
25915 AM - Taxi Dispatch - unfortunately right next to 25910 FM (when I can hear it, which I can't today)
26305 AM - Voice traffic, likely truckers (lots of noise toys, heavy QSB)
26375 AM - Same as above
26515 AM - Taxi Dispatch
26805 AM - Taxi Dispatch with roger beeps, noise toys
27045 AM - Taxi Dispatch (this is within the legal CB band, but is not a legal CB channel.  It is, in fact, a RC frequency!)
27425 AM - Taxi Dispatch, with QRM from SSB activity on the same freq and 27420 USB
27445 AM - Taxi Dispatch
27515 AM - Taxi Dispatch (I hear this one the most often and usually with the strongest signal)
27775 AM - AM voice traffic, likely taxis
27905 AM - Taxi Dispatch

The high 25 to low 26 range seems to be the most active when the band is open, followed by just below 28.  All in AM mode. 
U.S. East Coast, various HF/VHF/UHF radios/scanners/receivers

Offline ChrisSmolinski

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Re: The taxis are back (26-28 MHz)
« Reply #1 on: October 20, 2015, 2209 UTC »
Thanks for the logs, I am hearing some now.
Chris Smolinski
Westminster, MD
eQSLs appreciated! csmolinski@blackcatsystems.com
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Offline R4002

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Re: The taxis are back (26-28 MHz)
« Reply #2 on: October 20, 2015, 2350 UTC »
No problem Chris :)

The 26805 one is a new catch for me - the others (namely 27425, 27445 and 27515) are heard quite often.  My assumption is that these taxi companies are using export radios with vertical antennas (so anywhere from 20w to 100w AM power).  The dispatchers are usually YLs and have elaborate roger beeps or even music playing under their voices as they transmit.  I'm listening to the 26805 AM station right now (2335 UTC).  The other usual Mexican AM frequencies are also active: 26555 LSB, 26575 AM and 26585 AM.  Nice audio from a station on 26575 AM pushing the needle to the wall.  These Mexican high power stations run several kilowatts.  

Other frequencies I've logged this evening (band appears to still be open!) Notice the pattern with the band (alpha) designation + the channel number:

26105 AM - Band B channel 4 - English and Spanish language traffic, appears to be truckers
26135 AM - Band B channel 7 - Spanish language traffic, possibly taxi dispatch
26555 LSB - Band C channel 4 - Spanish language traffic, heavy QRM
26585 AM - Band C channel 7 - Very busy calling "shootout" channel.  High powered stations
26615 AM - Band C channel 9 - Spanish language traffic
27065 AM - Band D (legal CB band) channel 9 - Spanish language traffic
27455 USB - Band E channel 4 - Latin American calling frequency
27515 AM - Band E channel 9 - Taxi Dispatch

Channels 4, 7 and 9 appear several times here.  I believe the common practice for many of these operators is to simply pick a channel and then move the band switch up and down until a clear frequency is found.  A large number of export radios are NOT equipped with frequency displays.  Just a channel display plus a bandswitch.  Some radios complicate things further by having a 3 or 4 position bandswitch plus a "high band/low band" toggle switch that turns those 3 or 4 bands into 6 or 8 bands.  Very easy for somebody to find themselves in the middle of the 10 meter CW portion without realizing it (or caring).  Interesting that 26555 LSB is the "lowers" sideband frequency and 27455 USB is the "uppers" sideband frequency.  There is a method to the madness that is 11 meters.  

For the most part I have noticed that Spanish language traffic, especially on the "uppers" side (that is, 27405 to 28000) is usually in USB, and English language traffic is mostly in LSB.  The notable exception being stations working on 27555 USB and those that have QSYed from 27555 USB.  This afternoon I heard a lengthy QSO on 27550 USB between several US stations and a Brazilian station (IDed as 3 Radio Charlie 014).  They had QSYed from 27555 USB.

On top of this, the vast majority of traffic heard on the "lowers" (that is, below CB channel 1 so 26965 and down to 25000 or so) is in AM mode.  The exceptions being 26225, 26235, 26240, 26500, 26540 and 26555.  Everything else is in AM.  This includes US based stations (26915, 26885, 26835, 26815 and 26775 are the common ones I've heard truckers/American freebanders using - all in AM) as well.

I don't know if I'd call it a "gentleman's agreement" but considering the illicit nature of 11 meter freeband it is an interesting thing to note.  Given that 11 meters is effectively abandoned by other services (save for OTH radar) and there is effectively no enforcement of laws on this frequency band - the 25-30 MHz range will remain a fascinating, albeit lawless, corner of HF.  
« Last Edit: October 20, 2015, 2353 UTC by R4002 »
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Offline ChrisSmolinski

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Re: The taxis are back (26-28 MHz)
« Reply #3 on: October 21, 2015, 1434 UTC »
Thanks for your comprehensive post, R4002, that was one of the most informative things I've read about 11m!

As of 1430z, the UK CBers are starting to roll in. I am somewhat limited by antennas, the sky loop is not very good for 11m, probably something to do with it being on the order of 18 wavelengths long. The 48mb dipole works OK, but not great.
Chris Smolinski
Westminster, MD
eQSLs appreciated! csmolinski@blackcatsystems.com
netSDR / AFE822x / AirSpy HF+ / KiwiSDR / 900 ft Horz skyloop / 500 ft NE beverage / 250 ft V Beam / 58 ft T2FD / 120 ft T2FD / 400 ft south beverage / 43m, 20m, 10m  dipoles / Crossed Parallel Loop / Discone in a tree

Offline R4002

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Re: The taxis are back (26-28 MHz)
« Reply #4 on: October 21, 2015, 1709 UTC »
I appreciate it Chris :)

I run a dipole antenna cut for 26.000 as well as my usual wire antenna setup.  Most of my logs are heard with the dipole (or my various mobile antennas). 

I've heard tons of US and Latin American AM and SSB activity in the past 20 minutes or so of scanning the band, as well as a faint STL signal on 25950 FM and some UK FM activity on 27781 FM (UK FM channel 19).

Hopefully these openings will continue.  11 meters is always a thrill!
U.S. East Coast, various HF/VHF/UHF radios/scanners/receivers