Messages

106

VHF/UHF Logs, including satellites and radiosondes / French EPAR Data Link 31 MHz Band

« on: December 14, 2023, 1524 UTC »

31.325 MHz coming in very nicely at 1020 local time (US Eastern Time) polytone data signals.  French traffic control traffic signal control link system EPAR - I've seen it referenced as EPARS as well.  Receiver location:  Richmond VA.  Pro-106 scanner with HYS 51 inch telescoping CB whip antenna HYS 51" 27MHz CB antenna.  Also can hear it with the RadioShack center-loaded scanner/ham antenna 20-006 20-006A and the Cobra HA-TA 27" telescopic CB radio whip antenna with BNC connector "HT-1" antenna, sold under many names.  It is also base-loaded and Cobra HA-TA seems to be the most common brand name and model for that particular antenna.  Just like the HYS 51" antenna, simply reducing the length ever so slightly makes the antenna resonate in the 30-35 MHz region.

Known to use the following additional frequencies:

31.4375 MHz
31.4625 MHz
31.6875 MHz
31.925 MHz
31.975 MHz

31.325 and 31.975 seem to be the most commonly heard, along with 31.6875 MHz.  They come in nicely in NFM mode, but also in USB or LSB.  31.6875MHz tunes in fine on 31.690 MHz or 31.685 MHz if you're stuck in the proverbial 5 kHz steps land. 


31.325MHz sometimes has voice comms on it, either Asian fishery radio (27.5 MHz - 39.475 MHz, 25 kHz steps, NFM with carrier squelch (CSQ) simplex only, various LMR systems, a paging system operating on 31.320 MHz (unknown location), US based two way radio systems also on 31.3200 MHz 31.32 MHz and of course military FM comms on 31.325 MHz FM 30-88 MHz. 


The EPAR system data sounds very similar to digimode ROS (it sounds very musical).  In addition to the amateur bands, ROS can be found on 27.635 MHz, 26.735 MHz, 26.740 MHz, 27.235 MHz and 27.245 MHz on the 11 meter CB radio band.  27.235 and 27.245 being CB radio channels 24 and 25 respectively.  Most of the time it’s in FM mode but USB has been noted as well, especially on 27.635MHz. 

107

VHF/UHF Logs, including satellites and radiosondes / Re: Canadian Army VHF low-band skip

« on: December 14, 2023, 1517 UTC »

30.150 MHz FM is a good one.  I've heard a lot of traffic on there during this cycle and in during previous sunspot peaks.  It's not as consistent as, say, 30.450 MHz FM, but it's close. 

Others including 30.300 MHz, 30.600 MHz, 30.650 MHz, 30.800 MHz, 31.000 MHz, 31.100 MHz, 31.150 MHz and many many others come to mind (including 31.700 MHz FM, 31.750 MHz, FM, 31.900 MHz FM.   The 30-35 MHz region is popular, regardless of other signals/activity on/near the frequency.  A good example is 30.65 MHz FM.  There's a strong land mobile system that uses 30.640 MHz FM (among many other frequencies) and often both 30.64 and 30.65 MHz are coming in at the same time. 

I don't know about Canadian allocations, but US military has exclusive (primary) allocations for

30.000 MHz - 30.550 MHz
32.000 MHz - 33.000 MHz
34.000 MHz - 35.000 MHz
36.000 MHz - 37.000 MHz
38.000 MHz - 39.000 MHz
40.000 MHz - 42.000 MHz - note, there are several US government users of this band as well, i.e. SNOTEL on 40.670 MHz
46.600 MHz - 47.000 MHz
49.600 MHz - 50.000 MHz

Of course, they have secondary assignment for the spaces in-between and the whole 30-88 MHz band, effectively.  They often use frequencies like 35.700, 31.300, 45.500, 45.300 and others that are assigned to Part 90 land mobile on a primary basis.  That also includes military use of frequencies in the 6 meter amateur band 50MHz band 50-54 MHz.  As long as they're not interfering...

Remember the PRC-77, PRC-25 and VRC-12 family of radios did have a high band and low band, low band being 30.000 MHz to 52.950 MHz and high band being 53.00 MHz to 75.950 MHz, or 30-52 MHz and 53-76 MHz on the radio's front panel. 

The nice thing about running wideband FM voice is your signal to noise ratio is better.  Also, a non-standard tone squelch means chances of QRM from land mobile (LMR) users on the same frequency or nearby frequency is significantly reduced.  25 kHz is still the standard, but, as indicated, many radios used by militaries worldwide are capable of 12.5 kHz steps, so 30.0000 MHz to 87.9875 MHz instead of 30.000 MHz to 87.975 MHz.  Voice encryption, both wideband (25-30 kHz bandwidth) and narrowband (10-15 kHz bandwidth, roughly), plus various digital modes and multiplexed voice/data links or data-only links are also found in the 30-88 MHz spectrum.   In many instances, use of a single frequency system is the standard/norm (vs. frequency hopping).  Voice encryption is possible in SC (single channel / single frequency) and FH (frequency hopping) modes.

I believe 49.900 MHz is part of a repeater system (RETRANS), I believe in North Carolina (Fort Bragg).  I know they're also on 41.850 MHz FM, 41.950 MHz FM and many others.

150.0 Hz squelch is the name of the game.  All my scanners decode it as 151.4 Hz.  The only military comms on VHF low that I've noted without the tone squelch aren't really comms per se - but the Canadian military beacon YSD for CYSD heliport / helipad on 36.600 MHz (modulated CW "Y S D" followed by a tone burst - just like a NDB beacon).  I'm confident that YSD on 36.6 MHz FM is carrier squelch.  What the military calls "noise squelch" or "old squelch".

New squelch = 150 Hz tone operated squelch. 
Old squelch = carrier operated squelch (CSQ) or "noise squelch".   

Various secure voice signals can be seen on a waterfall display when the band is open. 

108

VHF/UHF Logs, including satellites and radiosondes / Re: A temporary repeater on 151.625MHz, VHF DOT FREQ? It was...

« on: December 14, 2023, 1504 UTC »

Thursday afternoon, 11/30/2023, I was again hearing chatter on that VHF Licensed DOT Colored FREQ of 151.625MHz, over a scanner. Usually, it's the tower workers using that to communication when climbing that American Tower, 600ft TV tower, that's 1 mile North of me. However, I was hearing a +1 sec repeater tail on this, this time. A portable / mobile flat-pack repeater? Must have been, since I didn't hear that the next day. That, and I was getting ready for work Thursday afternoon. That, was different.

151.625 MHz is the RED DOT frequency, and its an itinerant frequency.  There are licensed users of this frequency with portable/temporary repeaters on their licenses.  Much like

451.800
451.8125

464.500
464.550

are mostly used for simplex comms, as are

456.800
456.8125

469.500
469.550

But temporary repeaters / portable repeaters operating on those frequencies (low side is repeater output, +5 MHz is the input) are also quite common.

With VHF, the itnerant frequencies are:

151.505
151.5125
151.625
151.640
151.700
151.760
154.5275
158.400
158.4075

With 151.625 MHz having the least restrictions on power output.  Usually the input will be 154.5275, 158.400 or 158.4075, but there's nothing stopping somebody from using, say, 151.505 or 151.5125 or 151.700 or 151.760 as an input frequency, as long as they are licensed appropriately. 

Around here, there are plenty of low power (handheld) users of 151.625 and the others, along with a handful of high power (110+ watts) licensed itinerant users.  One of the Medevac helicopter providers for this area has a backup system that uses 151.625, 152.5275 and 158.4075 (with DCS coded squelch).  I've heard their dispatch traffic over those three frequencies, when, for whatever reason, they are having difficulty with their main dispatch system on UHF.  I can't imagine the amount of QRM the aircraft have to deal with, especially on 151.625 MHz.

109

10/11 meters / 25-28 MHz 11 Meter Activity 25-30 MHz Via G8JNJ SDR 14 Dec 2023

« on: December 14, 2023, 1458 UTC »

25.615 MHz AM - Spanish language chatter, probably not a taxi cab
25.625 MHz LSB - UNID language freeband 11m comms 25MHz band
25.650 MHz FM - FM-CW OTH Radar pulse, 30 kHz bandwidth 30kHz BW center freq 25.65 MHz 25650 kHz
25.665 MHz AM - Spanish language taxi dispatcher
25.670 MHz FM - Russian taxi radio dispatcher - Russian radio taxis 26670 FM
25.685 MHz AM - Spanish language freeband CB, fair to weak (heavy fading)
25.695 MHz AM - Taxi cab dispatcher - Mexico - SIO 222, known user of this freq. 25695 AM SS YL taxi
25.725 MHz FM - Russian taxi cab radio dispatch, very deep fading
25.735 MHz AM - Spanish language freebander comms (possible radio taxi dispatcher)
25.755 MHZ AM - US freeband / out of band CB traffic, probably land mobile users, farmers, etc.
25.775 MHz LSB - Freebanders, Spanish language
25.800 MHz AM - Weak AM signal noted (broadcast station)
25.825 MHz AM - Spanish language comms, very busy
25.830 MHz FM - Russian taxi cab radio dispatch, YL dispatcher
25.845 MHz AM - Spanish language taxi cab dispatch
25.855 MHz AM - Spanish speaking OMs, possible taxi radio chatter
25.865 MHz AM - Taxi cab dispatch, Spanish language, likely Latin America (heavy QRM)
25.865 MHz AM - Spanish speaking OMs having QSO, very strong signals (mixing with other signals on frequency)
25.865 MHz FM - Russian taxi cab dispatcher lady, heavy QRM from AM voice traffic on same frequency
25.875 MHz FM - UNID language, two way comms - possible land mobile or freeband CB
25.955 MHz AM - Spanish language comms - very good signals SIO 444
25.985 MHz AM - Spanish language chatter, freeband CB truck drivers?
25.985 MHz LSB - Spanish language freeband, informal QSOs
25.985 MHz LSB - Italian speaking freeband chatter
26.005 MHz AM - Taxi cab radio dispatcher - Latin America
26.045 MHz AM - Mexican taxi cab dispatch
26.055 MHz FM - Taxi cab dispatch, Russia - YL dispatcher
26.075 MHz AM - Italian language comms
26.085 MHz AM - US freeband CB radio chatter - possible snow plows or dump trucks, informal chatter
26.105 MHz AM - Busy frequency, popular Mexican trucker frequency
26.115 MHz FM - Russian taxi cab dispatcher
26.135 MHz AM - Spanish speaking two-way comms, probably trucking company comms
26.145 MHz AM - Spanish language taxi radio dispatcher - Mexican accent
26.150 MHz FM - POCSAG paging, sporadic
26.165 MHz FM - Russian taxi cab radio dispatcher
26.165 MHz FM - Very strong FSK signal
26.175 MHz AM - US out of band CB radio chatter, midwestern accents - truck drivers or possible hunt club radio
26.200 MHz FM - POCSAG paging, very busy - FM carrier signal transmitted with no page is being sent, like 27.450 MHz
26.205 MHz AM - Taxi radio dispatch - Latin America, possible Mexican radio taxi
26.225 MHz USB - Mexican freeband 11m calling frequency, active
26.245 MHz FM - Russian taxi cab dispatch, very heavy QRM from wideband CODAR signal 26.2 MHz - 26.35 MHz
26.300 MHz FM - POCSAG paging, FM carrier transmitted when idle (see 26.200 MHz, 27.450 MHz)
26.350 MHz FM - POCSAG paging pager frequency
26.375 MHz AM - Spanish language taxi cab dispatcher
26.400 MHz FM - POCSAG paging pager frequency
26.420 MHz USB - Polish - very busy
26.435 MHz AM - US out of band land mobile users, YL dispatcher, southern accents
26.475 MHz USB - Spanish language - likely freebanders
26.500 MHz FM - POCSAG paging pager frequency
26.515 MHz AM - US land mobile comms, YL dispatcher, southern accents - dispatcher "Brandy"
26.525 MHz AM - US land mobile comms, freeband CB radio
26.540 MHz LSB - Spanish language, stations that QSY'ed from 26.555 LSB
26.555 MHz LSB - Spanish language freeband calling frequency
26.575 MHz FM - German CB radio chatter, strong signals - German CB radio channel 42
26.585 MHz AM - Mexican freeband CB trucker channel, very busy
26.595 MHz AM - Mexican CB freeband activity
26.600 MHz FM - POCSAG paging signals - weak to very strong
26.605 MHZ FM - Russian taxi radio taxi dispatcher, full quieting at 1340 UTC
26.605 MHz FM - German CB radio comms, German CB radio channel 45
26.605 MHz AM - Spanish language, possibly Latin American taxi cab
26.615 MHz FM - Russian taxi cab radio taxi dispatcher controller Olga
26.615 MHz AM - Portuguese
26.620 MHz FM - POCSAG paging signals
26.625 MHz FM - Russian taxi cab YL dispatcher Olga coming in full scale
26.630 MHz FM - Russian taxi cab radio taxi, YL dispatcher "Olga" very good signal
26.635 MHz FM - POCSAG paging signals
26.650 MHz FM - FMCW OTH Radar bursts
26.650 MHz FM - Russian taxi cab radio taxi, YL dispatcher + OM drivers
26.650 MHz FM - POCSAG paging signals
26.655 MHz AM - Numerous AM signals on/near 26655 AM
26.655 MHz AM - Italian
26.655 MHz FM - Russian taxi cab radio taxi dispatch, heavy QRM from 26.655 MHz AM and 26.65 MHz FM
26.665 MHz AM - Spanish, from Spain!
26.665 MHz FM - Russian taxi cab dispatcher, YL dispatcher full scale!
26.670 MHz FM - Russian language, OM and YL dispatcher, likely taxi cab
26.675 MHz AM - Spanish language, weak
26.675 MHz AM - Spanish language taxi cab dispatch - possibly Mexico City radio taxi
26.675 MHz FM - German language CB comms
26.675 MHz FM - Russian taxi cab dispatcher
26.680 MHz FM - Russian taxi cab - radio taxi dispatcher controller - YL dispatcher SIO 444 very good
26.685 MHz AM - Spanish - OMs chatting, possibly Mexican truckers or Mexican / Latin American LMR comms 26685 AM
26.695 MHz FM - POCSAG paging signals - numerous paging signals on top of each other
26.700 MHz FM - POCSAG pager signals
26.705 MHz FM - PCOSAG paging signals and other data bursts
26.715 MHz AM - Big radios, Spanish language - Caribbean area (well known frequency)
26.720 MHz FM - Russian taxi cab radio dispatcher - YL taxi controllers Olga CIS taxis 26MHz 27MHz
26.725 MHz AM - Spanish language, sounds like Caribbean and Puerto Rico 
26.730 MHz FM - Russian taxi cab radio dispatcher
26.735 MHz AM - US freeband CB radio comms, probably truck drivers
26.745 MHz FM - POCSAG paging
26.750 MHz FM - Russian taxi cab radio comms PMR LMR 26.75 MHz FM
26.755 MHz FM - German language CB comms
26.755 MHz AM - US freeband CB chatter, truck drivers, possibly snowplows
26.760 MHz FM - Russian taxi cab radio dispatch, heavy QRM from the US CB radio chatter on 26.755 AM
26.765 MHz AM - Mexican taxi cab - Matamoros, Mexico (see also: 27.755 MHz AM, 27.765 MHz AM, several others)
26.775 MHz FM - Russian taxi cab radio taxi dispatcher, OM drivers replying
26.785 MHz AM - US freeband CB comms, truck drivers on export radios
26.795 MHz AM - US freeband CB comms, truckers, other stations, very busy
26.800 MHz FM - POCSAG paging signals
26.805 MHz FM - FM calling frequency, 26.805 FM club frequency, busy with US and other stations
26.815 MHz FM - POCSAG paging signals, sporadic
26.820 MHz FM - Russian taxi cab radio comms
26.825 MHz AM - Taxi cab dispatch, Spanish language, Mexican acccents
26.825 MHz AM - US truckers, informal QSO
26.835 MHz AM - US stations, midwestern accents, stations working DX
26.840 MHz FM - Russian taxi cab radio dispatch, Russian land mobile radio 26MHz band
26.845 MHz AM - US freeband CB radio chatter, truck drivers?
26.855 MHz AM - Spanish language, probably taxi cab dispatcher
26.865 MHz AM - US stations "he's coming out right there on your left"
26.875 MHz FM - Data stream, FSK "chirp"
26.875 MHz FM - German language CB comms
27.875 MHz AM - US freebanders, also Spanish language comms on frequency at the same time
26.885 MHz AM - US free band 11m CB comms, possibly logging trucks
26.895 MHz AM - Latin American radio taxi cab dispatch, YL dispatcher lady reading numbers in Spanish
26.900 MHz FM - POCSAG paging
26.905 MHz AM - "Galaxy Saturn" - US freeband CB radio
26.915 MHz AM - US freeband calling frequency, active
26.925 MHz AM - Spanish language comms
26.925 MHz FM - US and other country freeband chatter, heavy QRM from 26.925 MHz AM
26.935 MHz AM - Spanish language, taxi cab dispatch lady
26.945 MHz FM - Non-stop data bursts and POCSAG paging signals
26.945 MHz AM - US stations, free band operators - once the data signals faded away
26.945 MHz AM - Spanish language chatter on frequency at the same time as US stations
26.950 MHz FM - FSK bursts
26.950 MHz FM - POCSAG paging pager signals
26.955 MHz AM - Spanish language taxi cab dispatcher
26.955 MHz FM - Russian taxi cab dispatcher
26.955 MHz FM - Nonstop data bursts
26.955 MHz FM - POCSAG paging signals
26.960 MHz FM - Nonstop data bursts, can hear voice comms underneath

Due to the stations-on-every-frequency nature, only interesting/unique logs are below for the 27.405 MHz - 28 MHz range

27.410 MHz USB - UK stations working UNID station, sounds like US station, very strong, mention of World Radio
27.415 MHz USB - Spanish language
27.415 MHz AM - Spanish langauge taxi cab dispatcher
27.420 MHz LSB - "Stevie Jones, he would come to Fort Lauderdale, he was a nice guy" "yeah, I met some assholes too" - US station working UK station
27.440 MHz FM - Spanish speaking freebanders, nice strong FM deviation, obliterating SSB signals on/nearby
27.450 MHz FM - Unmodulated FM carrier signal, sporadic data bursts - carrier signal still there at 1500 UTC
27.465 MHz AM - Canale 45 - Italian BIG RADIOS with lots of ECHO
27.505 MHz FM - Very strong POCSAG paging signals - S7 to S9+20dB
27.635 MHz AM - US stations, almost certainly truck drivers
27.655 MHz AM - US freeband activity, truck drivers
27.731 MHz FM - UK FM CB activity - UK FM CB Channel 14 freq 27.73125 MHz FM
27.735 MHz AM - Spanish language taxi radio dispatch - Mexican taxi cab CB radio dispatcher
27.755 MHz AM - Spanish language taxi cab dispatch - Mexican radio taxis dispatch
27.771 MHz FM - UK FM CB radio chatter, UK FM CB Channel 18 freq 27.77125 MHz FM
27.781 MHz FM - UK FM CB CH19 very busy 27.78125 MHz FM
27.785 MHz AM - Spanish language taxi dispatcher, heavy QRM from 27.781 FM
27.785 MHz FM - Spanish speaking freebander calling CQ 11 metros, CQ America del Sur (CQ South America 11 meter)
27.801 MHz FM - UK FM CB CH21 - sporadic activity 27.80125 MHz FM
27.815 MHz AM - Spanish language taxi cab dispatch - well known users on this frequency
27.845 MHz AM - US truckers using export radios, CB radio out of band signals
27.855 MHz USB - UK station working ?
27.861 MHz FM - UK FM CB Radio Channel 27 active, local CB comms?
27.865 MHz AM - Spanish speaking YL taxi cab dispatcher
27.875 MHz AM - US freeband CB radio chatter, southern accents
27.885 MHz FM - POCSAG paging pager signals
27.885 MHz AM - US truckers using export radios, northeastern US accents
27.901 MHz FM - UK FM CB Radio Channel 31 - UK CB radio chatter 27.90125 MHz FM
27.961 MHz FM - UK FM CB Radio Channel 37 - UK CB radio chatter 27.96125 MHz FM
27.965 MHz FM - Russian taxi cab dispatcher lady - Olga Russian taxis 27 MHz 28 MHz
27.975 MHz AM - US stations, truckers or similar land mobile users
27.981 MHz FM - UK FM CB Radio Channel 39 - UK CB radio chatter 27.98125 MHz FM
27.985 MHz FM - FM-CW OTH-Radar
27.991 MHz FM - UK FM CB Radio Channel 40 - Active
27.995 MHz LSB - French language, possibly Canadian freeband CB
28.005 MHz AM - Spanish language chatter, weak to fair signals
28.035 MHz AM - Spanish language signals, heavy fading
28.055 MHz AM - Spanish language two-way comms, trucking company, taxi or other business radio like use
28.074 MHz USB - Nonstop FT8 data signals
28.085 MHz AM - Numerous Spanish language signals on frequency
28.115 MHz FM - Russian taxi cab dispatcher - YL dispatcher "Olga" active on 10m
28.135 MHz FM - Russian taxi cab dispatcher - previously logged taxis on 28135 FM
28.165 MHz AM - Spanish language taxi cab dispatcher - taxis on 28 MHz
28.180 MHz USB - Nonstop FT4 data signals
28.225 MHz AM - Spanish language taxi cab - Latin American taxi cab company
28.245 MHz AM - Taxi cab radio dispatch radio taxi Latin America
28.305 MHz AM - Spanish language CB-like chatter - band F, channel 40 on most export radios

110

10/11 meters / Re: FM Chatter on 11 Meters - CB Channel 29 and out of band 26.805 MHz FM etc. 11/28

« on: December 07, 2023, 1430 UTC »

26.805 MHz FM is busy again this morning (US East Coast Time) along with numerous other out of band freqs

111

10/11 meters / Re: Midland 75-160 FCC ID: F9GRC-3000 - 3 Channel FM 27 MHz Walkie Talkies Part 15

« on: December 01, 2023, 1458 UTC »

I actually recently picked up a few TRC-224 3-channel CB handhelds.  The crystal controlled ones with "3 watt output".  They actually are 1.5 watt output (on high power). 

They've got massive center-loaded telescopic whip antennas.  I've got plenty of crystals to play around with, including some for 27.675 MHz, 27.725 MHz, 27.775 MHz and 29.825 MHz (TX and RX crystal pairs).  Plus a few extra TX/RX pairs for CB channels 11 and 30 and maybe a few others.  Yep, you read that right.  29.825 MHz.

As far as going the distance with CB handhelds, my past experience with the 3-channel "3 watt" RadioShack/Realistic HTs like these are the winners. 

I also recently acquired a handheld CB that does AM and FM.  PNI Escort HP 82.  Nice little rig.  Plus, it has the same "Kenwood Style" audio connector that all the Baofeng, etc. Chinese handhelds have.  So, in theory (and I've tested it, it does work) I could set up my own simplex repeater on CB.  The PNI HP82 comes with one of the adapter plugs that has a cigarette lighter plug for 12VDC / 13.8VDC as well as a pigtail with a SO-239 socket on the end to plug it into an external antenna. 

On the topic of the Midland radios, they are very wide FM (receive and transmit).  On "Channel 1" (27.095 MHz) I could hear AM CB skip coming in very clear.  Naturally the big signals from 27.085 were coming in but I was hearing 27.105 MHz and others mixing in.  Same when I tuned to 27.145 MHz and whatever channel 3 is (27.240 MHz?  maybe 27.245 MHz?)  The FM deviation is so wide that it doesnt seem to matter.  It also explains my difficulty in figuring out exactly which frequencies these two Midland 75-160 handhelds have in them...because I was trying to do so with a quite narrow FM FM CB radio. 

More experimentation to come.  I don't expect much.  49MHz Part 15 like range.   

The TRC-224 rigs show more promise.  Plus, its much easier to swap crystals in and out of them, they have a connector for an external antenna (RCA type connector, I did get some RCA to SO-239 adapters and some coax jumpers, PL-259 to PL-259, PL-259 to SO-239 - various lengths, etc.  Since I need coax for the Pager Beacon II project. 

112

10/11 meters / Re: FM Chatter on 11 Meters - CB Channel 29 and out of band 26.805 MHz FM etc. 11/28

« on: November 30, 2023, 1844 UTC »

1837 UTC on 30 November 2023:

FM activity coming in on 26.805 MHz FM.  "164 Pennsylvania" at 1838 UTC with a nearly full scale signal. 

Lots of AM voice from US-based freeband CB radio operators in the 26 MHz range - that "lowers" or "Band C" 26.515 MHz - 26.955 MHz, including the famous 26.915 MHz AM frequency and 26.955 MHz AM itself.

26.555 MHz LSB and 26.585 MHz AM (and several other nearby freqs) are super super busy with Mexican CB radio traffic.  Noted use of 26.540 MHz LSB as a QSY or alternate frequency because of how congested 26.555 LSB is.

113

10/11 meters / Re: Midland 75-160 FCC ID: F9GRC-3000 - 3 Channel FM 27 MHz Walkie Talkies Part 15

« on: November 29, 2023, 1428 UTC »

Actually, the channel frequencies may be wrong.  I need to open these radios up.

FM audio quality is much better on:

27.100 MHz FM for Channel 1
27.150 MHz FM for Channel 2
27.240 MHz FM for Channel 3

instead of

27.095 MHz FM
27.145 MHz FM
27.255 MHz FM


I checked 27.250 MHz as well, which resulted in distorted audio.  27.255 MHz is very distorted.  I need to check these and actually look at the crystals. 

Interesting pieces of equipment.  According to the FCC ID documentation, they operate anywhere between 26.960 MHz and 27.270 MHz.  27.1 MHz, 27.15 MHz and 27.24 MHz do fall within that band.  I guess I just assumed they would be exactly on
26.995 MHz
27.045 MHz
27.095 MHz
27.145 MHz
27.195 MHz
or
27.255 MHz

Using the “in-between” frequencies actually does make sense to a certain degree, with the high FM deviation the possibility of adjacent channel AM voice QRM is lowered at least some.   The Italian forum talking about these radios claims they’re on 27.120 MHz FM.  It also indicates 2km to 4km range, which is pretty impressive for Part 15 if that’s actually the case. 

The box says 1/2 mile, which is not 2-4 km.  1/2 mile is 0.8 km 800 meters. 

114

10/11 meters / Re: Midland 75-160 FCC ID: F9GRC-3000 - 3 Channel FM 27 MHz Walkie Talkies Part 15

« on: November 29, 2023, 1343 UTC »

I’ll be doing some testing with these and the 49MHz gear and will be posting the results on YouTube and on here as well.

115

10/11 meters / Re: FM Chatter on 11 Meters - CB Channel 29 and out of band 26.805 MHz FM etc. 11/28

« on: November 28, 2023, 2115 UTC »

2115 UTC:

26.805 MHz FM 26805 FM still very active

116

10/11 meters / FM Chatter on 11 Meters - CB Channel 29 and out of band 26.805 MHz FM etc. 11/28

« on: November 28, 2023, 2102 UTC »

26.805 MHz FM club very active today and even now.  November 28th, 2023.

Noted in-band chatter in FM mode on CB radio channel 29 frequency 27.295 MHz FM.  Also some sporadic FM use on:

CB Channel 30 - frequency 27.305 MHz FM
CB Channel 23 - frequency 27.255 MHz FM - mostly AM voice, RCRS data bursts and some SSB activity on/near 27.255MHz. 

CB Radio Channel 29 seemed to have the most FM activity.  Some FM noted on channel 40 as well 27.405 MHz FM.

117

10/11 meters / 26.765 MHz AM Taxi Cab Radio Dispatcher YL Booming In 2055 UTC 28 Nov 2023

« on: November 28, 2023, 2059 UTC »

26765 AM Juanita is coming in loud and clear just shy of 4:00 PM Eastern Standard Time (2100 UTC).  Tuned in locally around 2050 UTC and then checked the W3HFU KiwiSDR and other receivers - she is on all of them.  Lots of activity on the 25 MHz and 26 MHz frequencies too.

26.765 MHz AM Taxicab Radio Dispatcher - Mexico.   Probably Matamoros Mexico.  26765 kHz 26,765 MHz 26.765 MHz taxi cab radio dispatch.

118

10/11 meters / Re: 27.940 MHz Data / Pager System With Constant "Idle" Signal 27940 kHz

« on: November 25, 2023, 1959 UTC »

Here’s a video showing the waveform on a waterfall

27.940 MHz Data Signal With POCSAG Paging Underneath UNID Datalink 11 Meter Band G8JNJ SDR 11/16/23
https://youtu.be/FN4LZUrpz9w

119

10/11 meters / Re: Fishing Fleet Chatter 11m/10m 27.5MHz - 39.475 MHz - 23 November 2023

« on: November 25, 2023, 0129 UTC »

The Russian taxi cabs are worthy of their own thread, or threads.  They’re using the standard export radio / 10 meter radio coverages

“E” channel band plan raster - frequencies end in “5”.  This is the standard plans.  Often called “the fives”.  The most common plans are 25.615MHz - 28.305MHz and 25.615 - 30.105 MHz

25.615 MHz - 30.105 MHz 30.115 MHz
25.615 MHz - 28.305 MHz 28.315 MHz
25.165 MHz - 28.755 MHz 28.765 MHz
24.715 MHz - 30.105 MHz 30.115 MHz
24.265 MHz - 29.655 MHz 29.675 MHz
24.265 MHz - 30.105 MHz 30.115 MHz
26.065 MHz - 28.755 MHz 28.765 MHz

The “P” or “R” zeros plan - that is, everything -5 kHz. Polish CB band plan 26.960 MHz - 27.400 MHz. 

25.610 MHz to 30.100 MHz 30.110 MHz
26.060 MHz to 28.750 MHz 28.760 MHz
and so on

The second frequency is the +10 kHz switch frequency at the top of the range, but most radios are advertised as 25615-30105 or 25.165MHz to 28.755MHz even with the +10 kHz switch. 

So Russian CB is legally 26.060 MHz to 27.995 MHz, 5 kHz steps since both the zeros and fives are allowed. 

Many radios for the Russian market include a -5 kHz switch in addition to a +10 kHz switch. 

Seems like the majority of these systems use FM mode.  Most of the signals I’ve stumbled upon are on the “E” channel raster, the fives.  Frequencies like 29.965 MHz, 29.915 MHz, 29.865 MHz, 29.805 MHz, 29.755 MHz, 28.305 MHz, 28.265 MHz, 28.225 MHz, 28.195 MHz, 28.135 MHz, 28.115 MHz, 27.965 MHz, 27.885 MHz, 27.815 MHz, 27.775 MHz, 27.765 MHz, 26.895 MHz, 25.775 MHz, 25.975 MHz, 26.695 MHz, and so on. 

But I’ve come across numerous taxi radio dispatch comms on 28.260 MHz, 26.770 MHz, 28.880 MHz, 27.740 MHz, 27.900 MHz, 25.740 MHz, with many of them in the UK FM 27/81 CB band
27.60125 MHz - 27.99125 MHz, so Russian taxi controllers on, say, 27.730 MHz and 27.735 MHz and you’re trying to use UK FM CB Channel 14 - 27.73125 MHz FM…it’s just QRM city. 

While the majority of them appear to be below 28.3 MHz or 28.8 MHz, I’ve noted several in the spectrum above 29.7 MHz up to, well, 30.105 MHz / 30.110 MHz / 30.115 MHz. 

Nevermind the additional slew of Russian land mobile comms in the 29.7 MHz - 50 MHz band. 

The Alinco DR-135LH radio, for example, covers 33 MHz to 48.5 MHz and 57.0125 MHz to 57.5 MHz in 12.5 kHz spacing.  There’s also the various 43MHz Italian VHF CB radios 43.3 MHz - 43.5875 MHz that are very easily modified to cover 42.3 MHz to 45.0875 MHz or 42.300 MHz to 45.100 MHz (12.5 kHz steps), NFM voice. 

Lots of weird stuff coming out of Russia on 11m/10m and VHF low band.  Add the fishing fleets and it’s a real mess.  I bet 10 meters is unusable in large portions of the world when the band is as open as it’s been lately. 

120

10/11 meters / Fishing Fleet Chatter 11m/10m 27.5MHz - 39.475 MHz - 23 November 2023

« on: November 23, 2023, 1204 UTC »

Tuned via the excellent G8JNJ SDR at 1145 UTC on 23 November 2023, lots of paging signals, CB radio comms, Russian taxi cabs and so on.   Asian fishery radio Chinese 25W FM fishing boat radiotelephone dual mode signaling 27.5MHz-39.5MHz 480 channel.  So 27.550MHz is Channel 003.  27.575MHz is Channel 004.

Fishing fleet chatter fishing trawlers noted on:


27.5500 MHz FM CSQ 27550 FM
27.5750 MHz FM CSQ 27575 FM
27.6250 MHz FM CSQ 27625 FM
27.7500 MHz FM CSQ 27750 FM
27.7750 MHz FM CSQ 27775 FM
27.8250 MHz FM CSQ 27825 FM
27.8750 MHz FM CSQ 27875 FM
27.9000 MHz FM CSQ 27900 FM
27.9250 MHz FM CSQ 27925 FM
27.9750 MHz FM CSQ 27975 FM
28.0000 MHz FM CSQ 28000 FM
28.1250 MHz FM CSQ 28125 FM
28.2250 MHz FM CSQ 28225 FM
28.3250 MHz FM CSQ 28325 FM
28.5500 MHz FM CSQ 28550 FM
28.7750 MHz FM CSQ 28775 FM
28.8750 MHz FM CSQ 28875 FM
28.9000 MHz FM CSQ 28900 FM
29.1250 MHz FM CSQ 29125 FM
29.1500 MHz FM CSQ 29150 FM
29.7000 MHz FM CSQ 29700 FM
29.7500 MHz FM CSQ 29750 FM
29.7750 MHz FM CSQ 29775 FM
29.8000 MHz FM CSQ 29800 FM
29.8250 MHz FM CSQ 29825 FM
29.8750 MHz FM CSQ 29875 FM
29.9000 MHz FM CSQ 29900 FM
29.9750 MHz FM CSQ 29975 FM

I’m sure there’s plenty more above 30.000 MHz.  Several of the 27 MHz frequencies had QRM from SSB freebanders, UK FM CB, pagers, Russian taxi dispatchers and so on.  27.625 MHz FM suffered severe QRM from what sounded like a Link-11 data signal on/around 27.627 MHz or so, along with UK FM CB on 27.621 MHz FM. 

Hams and Russian taxis on 28 MHz and 29 MHz, but especially the 28-28.300 MHz portion tons of QRM.  27.575MHz active with AM CB signals from Italy, FM voice CB radio signals out of Russia and SSB CB signals out of everywhere, same with the obvious QRM from 27.555 MHz USB on 27.550 MHz.  27.500 MHz had strong AM voice on 27.505MHz plus POCSAG paging on 27505 on top of that.