Messages

226

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. 

227

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.

228

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

229

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.

230

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.

231

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

232

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. 

233

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.

234

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

« on: November 16, 2023, 1343 UTC »

There appear to be many different paging protocols in use.  Some of these systems seem to be POCSAG and others just sound like POCSAG.

There is a lot of 26 MHz band activity too.  I use 26.695 MHz / 26.745 MHz (plus center frequency 26.750 MHz) as well as 26.600 MHz, 26.645 MHz / 26.655 MHz and center frequency 26.650 MHz and the 26.850 MHz, 26.900 MHz, 26.945 MHz, 26.950 MHz, 26.955 MHz, 26.960 MHz, 27.300 MHz, 27.350 MHz, 27.360 MHz and 27.505 MHz ones as band opening indicators.

Plus there's the 27.450 MHz system (or systems) that transmit a continuous carrier when idle, and the 29.800 MHz, 29.900 MHz systems.  The 29.8 MHz and 29.9 MHz systems are believed to be located in the Nordic countries.

I don't know where 27.9400 MHz is coming from though.

Update: 

At 1344 UTC I tuned in to 27940 kHz FM 27.94 MHz FM and the signal is there.  I'm listening via SDRs located in the UK. 

There are at least two different transmitters with a carrier or pilot tone frequency:

Weaker of the two is on 27940.07 kHz, stronger of the two is on 27940.2 kHz.   There's POCSAG underneath this unique data burst mode, plus voice QRM from 27.940 MHz LSB and UK FM CB activity 27.94125 MHz FM. 

235

10/11 meters / Re: 26.110 MHz FM 26110 FM - Broadcast Audio Link STL IFB 1823 UTC 10 Nov 2023

« on: November 12, 2023, 1910 UTC »

It’s been just what I would call an “open mic” with the studio chatter and background conversations caught…other times it’s the same as the broadcast audio, including commercials.  I’ve also heard what sound like mic checks, audio feed equipment being checked, etc.

Unlike the 25.950 MHz FM 25950 FM signal that seems to be on the air all the time, this one is clearly switched on and off at points depending on…something.

Another interesting observation is the fact that sometimes my scanner / receiver decodes a PL tone or CTCSS tone of 218.1 Hz with the 26.110 MHz FM 26110 kHz FM signal.  218.1Hz is not one of the “false decode” tones like 118.8 Hz can [sometimes] be for signals with a really strong 60Hz AC hum (118.8 Hz being the closest tone to 120Hz…second harmonic) or 100.0 Hz for a station with a really bad 50Hz AC hum. 

I think 218.1 Hz tone is actually being used.  Back during the last sunspot cycle peak, when there was not only 25.950 MHz FM but also 25.910 MHz FM and 25.990 MHz FM active, they would be transmitting PL tones too. 

I believe 25.95 MHz is acting as a “channel marker” or “frequency squatter”.  It’s a de facto beacon, as is 26.11 MHz FM when it’s on the air. 

236

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

« on: November 11, 2023, 1727 UTC »

Edit:

I got my hands on two new in box 75-160 handhelds.  They are FM, and the channel frequencies are:

Channel 1 - 27.095 MHz FM
Channel 2 - 27.145 MHz FM
Channel 3 - 27.255 MHz FM

The FM deviation appears to be 5 kHz.  I checked using a multi-norm handheld set to the Poland band plan - AM/FM CB and was able to hear 27095 pretty much loud and clear on 27.100 MHz Channel 12R.  Same with 27145 coming in nicely on 27.150 MHz Channel 16R. 

Channel 3 is indeed 27255, CB channel 23 and I was able to hear RCRS data bursts on it.  Apparently a single-channel variant the Midland 75-150 FM Walkie-Talkie was also sold.  It advertises 1/2 mile range just like the 75-160 3-channel 27MHz FM walkie talkie box does. 



So I went on a bit of an eBay binge, ended up ordering a Maxon 49-HD 49MHz 5-channel FM walkie talkies and RadioShack TRC-512 / TRC-503 5 channel 49MHz handhelds, 27MHz paging transmitters (RadioShack PG-80, and Command Communications PrivatePage PS2000AN pager - which is similar to the RadioShack PG-99 pager 17-6020)

…and pair of Midland model 75-160 3-channel 27MHz FM Walkie Talkies. 

FCC ID F9GRC-3000 F9GRC3000

These indicate FCC Part 15 compliance on the back of the radios.  3 channels, indicated as 1/2/3 on the side of the radio.

FCC type acceptance date is 13 June 1991  - formatted as 1991-06-13.  FCC rule Part 15C, Grant Note 37.  Operating frequencies 26.96 MHz - 27.27 MHz. 

FCC Grant Note 37:


I found a thread on an Italian language forum about it being a “civil band” or “urban band” (CB radio) walkie talkie with 2-4 km range and it likely operating on 27.120 MHz.  Nothing is said about the 3 channels. 

https://www.elforum.info/topic/98890-statii-portabile-walkie-talkie-midland-cred-ca-destul-de-vechi/

Since these aren’t 49MHz handhelds and they’re FM mode they are intriguing to me.  They appear to be early 1990s vintage. 


One thing is the operating band for 27MHz Part 15 has changed very slightly over the years.  Now it’s 26.96 MHz - 27.28 MHz.  Old versions are 26.97 MHz - 27.27 MHz, 26.96 MHz - 27.27 MHz, etc. 

26.960 MHz - 27.270 MHz is the one that matches with this radio.  I know 15.227 is the same as 49.82-49.90 MHz in that it’s 10,000 microvolts/meter at 3 meters. 

These radios are listed as 1/2 mile range radios, which to me says more than the 12 microwatts or whatever 10,000 uV/m at 3m is.  Seems more like a 50mW to 100mW type rig…like the old 100 milliwatt single channel RadioShack handheld CB rigs TRC-91 or TRC-92 and several others. 

On another tangent, these could be turned into legal 11m 27MHz Part 15 beacon transmitters.  A blurry image of the radio’s PCB clearly shows a set of 3 crystals and another set of 3 crystals, likely a transmit/receive pair for each of the 3 channels. 

Once the radios arrive I’ll figure out what channels these things are actually on.  Since the operating band is 26.960 - 27.270 MHz, I’m assuming some combination of the RCRS channels…26.995 MHz, 27.045 MHz, 27.095 MHz, 27.145 MHz, 27.195 MHz and 27.255 MHz.  Avoiding 27.255 would make sense but who knows. 

Since it’s Part 15, in theory, it could be any 3 frequencies in the 26.96 to 27.27 MHz range, 27.120 MHz, 27.240 MHz and 27.250 MHz or whatever. 

Hopefully I’ll be able to update this thread with another piece of 27 MHz walkie talkie  history.  Now that FM is legal on Part 95 Class D CB radio, regular CB channels would be okay, but the RCRS channels are better for a potential beacon project. 

I’m interested in knowing what, if any difference in the associated Part 15 section 15.227 (47 CFR 15.227) in effect when these radios were approved. 

Also, what does this mean? Grant Note 37

FCC Grant Note 37
FCC Grant Note 37 signifies This device has shown compliance with new rules adopted under Docket 87-389 and is not affected by Section 15.37, transition rule

Here’s FCC Docket 87-389

https://docs.fcc.gov/public/attachments/DOC-342985A1.pdf

Does anybody have a copy of Part 15 as it was in 1991?

237

10/11 meters / 26.110 MHz FM 26110 FM - Broadcast Audio Link STL IFB 1823 UTC 10 Nov 2023

« on: November 10, 2023, 1826 UTC »

Listening via the W3HFU SDR, and also locally.

Heavy fading at 1820 UTC tune in.  Nice loud FM deviation. 

Faded down into the noise for 3-4 seconds at 1823 UTC...then faded back up to SIO 222 or so.  Even at a S-3 signal strength level, readability is...meh.

Signal strength jumped up dramatically for a few moments at 1824 UTC and then dropped back down.

The Latin American land mobile radio systems and freeband 11 meter CB operators are starting to pop up in the nearby spectrum 25-26 MHz as well.

At least right now, 25950 FM 25.95 MHz FM 25.950 MHz FM is nowhere to be heard. 

238

VHF/UHF Logs, including satellites and radiosondes / VHF Low Band DX Logs (Via UK Based SDR) 10 November 2023

« on: November 10, 2023, 1819 UTC »

Very short listening session this time. 

Via the (spectacular) G8JNJ SDR:







29.8000 MHz FM - Asian fishery radio chatter, busy frequency
29.8250 MHz FM - Asian fishery radio chatter fishing trawlers
29.8500 MHz FM - FM Carrier
29.8500 MHz FM - MFSK data signal, not POCSAG paging
29.9250 MHz FM - Asian fishery radio chatter - fishing fleet comms
29.9650 MHz FM - Russian YL taxi cab dispatcher, heavy fading
30.0000 MHz FM - FM carrier, the usual nonstop FM signal
30.0250 MHz FM - US military, radio checks
30.1500 MHz FM - US Military FM "Charlie 13" "Say again, over" - good signals
30.1500 MHz FM - Military comms - different group, wider FM deviation, UNID language
30.5000 MHz FM - Asian fishery radio chatter - fishing fleet comms
30.6400 MHz FM - US LMR / PMR = Business radio comms
30.6500 MHz FM - Military comms, FM voice and encrypted digital
30.7500 MHz FM - Asian fishery radio chatter
30.7600 MHz FM - US LMR / PMR, weak
30.7750 MHz FM - Asian fishery radio chatter - fishing fleet comms
30.8000 MHz FM - Asian fishery radio chatter - fishing fleet comms
30.8400 MHz FM - UNID land mobile - voice inversion scrambled signals
31.0000 MHz FM - Asian fishery radio chatter - fishing fleet comms
31.0250 MHz FM - Asian fishery radio chatter - fishing fleet comms
31.0800 MHz FM - US LMR / PMR
31.1000 MHz FM - Asian fishery radio chatter - fishing fleet comms, very busy
31.1200 MHz FM - US LMR / PMR - bus dispatch repeater, good signals
31.1250 MHz FM - Asian fishery radio chatter - fishing fleet comms
31.1500 MHz FM - Paging - very strong Greek POCSAG pager
31.2000 MHz FM - Data bursts, possibly fax or similar? very strong
31.2000 MHz FM - US LMR / PMR - construction
31.2250 MHz FM - Data bursts, possibly fax or similar? very strong
31.2250 MHz FM - Asian fishery radio chatter - very busy
31.3750 MHz FM - Data bursts, possibly fax or similar? very strong
31.4500 MHz FM - Data bursts, possibly fax or similar? very strong
31.5750 MHz FM - Data stream, fax?
31.5750 MHz FM - Military FM comms, heavy QRM
31.5800 MHz FM - US LMR / PMR, very difficult copy
31.6250 MHz FM - Asian fishery radio chatter
31.6500 MHz FM - Military FM comms
31.6500 MHz FM - Data bursts, similar to those heard on 31 MHz, 32 MHz and 33 MHz
31.9600 MHz FM - US LMR / PMR
31.9800 MHz FM - US LMR / PMR

239

10/11 meters / Re: Trying to understand and set up galaxy 2 1st post

« on: November 09, 2023, 2006 UTC »

Bumping an old thread because I stumbled upon some of these 3-channel 27MHz FM walkie talkies.

Midland model 75-160

FCC ID F9GRC-3000

FCC Rules Part 15C

Approved on 13 June 1991

Operating frequencies 26.960 MHz - 27.270 MHz

https://fccid.io/F9GRC-3000/amp

And Google Translation of a post from an Italian forum thread about them:

They low-power citizen band (CB) stations, with a range of 2 ... 4 km, work in the 27 MHz band (most likely 27.120 MHz).

Usually, the date of their manufacture is written on the electrolytic capacitors, so the station must have been produced approximately in the respective period. By all appearances - types of parts, design, way of making, etc. - it can be a model from the mid-90s

Note, I changed the formatting from 27,120 MHz to 27.120 MHz. 

Since they’re 3 channel radios, and the main PCB clearly shows two sets of three crystals, presumably a pair of crystals for each channel, one transmit and one receive, with the 455 kHz TX/RX difference. 

The channel selector simply says MULTI-CHANNEL

1
2
3

I’ve read that they use 26.995 MHz, 27.045 MHz, 27.095 MHz, 27.120 MHz, 27.145 MHz, 27.195 MHz, 27.250 MHz, 27.255 MHz and 27.270 MHz. 

Use of the RCRS channels would make sense.  Some sources call these 100mW output radios, others call them 50mW.  They remind me of the 100 milliwatt (actual output was 50 milliwatt) RadioShack single-channel CB walkie talkies like the TRC-92 and I know there were many many others. 

Sort of intrigued. 

240

VHF/UHF Logs, including satellites and radiosondes / YSD Beacon 36.600 MHz FM 36.6 MHz CYSD Anyone Heard It Recently?

« on: November 09, 2023, 1603 UTC »

Canadian military airport CYSD radio beacon, transmits "Y S D" in Morse code followed by a tone burst.  Similar format to a NDB or VOR type station.  No tone (does not have the usual 150 Hz tone squelch that military FM systems usually have - that usually decodes as 151.4 Hz instead of 150.0 Hz). 

It's FM, but comes in great in AM mode as well since its just modulated CW.  I believe its a 1000Hz tone, but I could be wrong.

I haven't heard it in many many months.  36.600 MHz is the frequency.  Strong FM deviation.  36.6MHz CYSD beacon YSD beacon 36600.0 kHz FM