Messages

316

VHF/UHF Logs, including satellites and radiosondes / Re: 151.625 MHz Business Band Itinerant Analog FM vs. DMR Digital Voice 12 Feb 2020

« on: February 14, 2020, 1523 UTC »

Just another update: 

Heard some more very strong DMR traffic on 151.625 this morning, along with some weak analog FM voice.  023 DCS code along with 67.0 Hz, 94.8 Hz, 97.4 Hz and 136.5 Hz CTCSS tones have been logged in the past.  I know the film school for the local university uses 151.625 and 151.955 for camera crew comms and other purposes.  I've logged them as using both 67.0 and 94.8 PL tones.  Unfortunately there's also a local funeral home that uses 151.625 with 97.4 Hz PL tone, and of course Crane Master doing 110 watts with 167.9 Hz PL.

I found the listing for the default factory frequencies for the Motorola RDX series RDV5100 VHF radio:

Channel 1 - 151.6250 MHz - 67.0 Hz PL
Channel 2 - 151.6250 MHz - 77.0 Hz PL
Channel 3 - 151.6250 MHz - 88.5 Hz PL
Channel 4 - 151.6250 MHz - 179.9 Hz PL
Channel 5 - 151.6250 MHz - CSQ - carrier squelch (no PL or DPL)
Channel 6 - 151.9550 MHz - 67.0 Hz PL
Channel 7 - 151.9550 MHz - 82.5 Hz PL
Channel 8 - 162.4000 MHz - CSQ - RECEIVE ONLY - "WC" (Weather Channel)
Channel 9 - 151.9550 MHz - 179.9 Hz PL
Channel 10 - 151.9550 MHz - CSQ - carrier squelch (no PL or DPL)




Here are the "27 business exclusive" frequencies available for the Motorola RDX and RDV VHF radios (and others, including the Kenwood TK-2400 series radios such as the TK-2400VP)

Frequency 01: 151.6250 MHz - itinerant
Frequency 02: 151.9550 MHz
Frequency 03: 152.8850 MHz
Frequency 04: 152.9150 MHz
Frequency 05: 151.7000 MHz - itinerant
Frequency 06: 151.7600 MHz - itinerant
Frequency 07: 152.9450 MHz
Frequency 08: 151.8350 MHz
Frequency 09: 151.8050 MHz
Frequency 10: 151.5125 MHz - itinerant
Frequency 11: 151.6550 MHz
Frequency 12: 151.6850 MHz
Frequency 13: 151.7150 MHz
Frequency 14: 151.7450 MHz
Frequency 15: 151.7750 MHz
Frequency 16: 151.8650 MHz
Frequency 17: 151.8950 MHz
Frequency 18: 151.9250 MHz
Frequency 19: 152.9000 MHz (incorrectly printed in some Motorola manuals as "152.7000 MHz")
Frequency 20: 154.4900 MHz
Frequency 21: 154.5150 MHz
Frequency 22: 154.5275 MHz - itinerant
Frequency 23: 154.5400 MHz
Frequency 24: 153.0050 MHz
Frequency 25: 154.5475 MHz
Frequency 26: 158.4000 MHz - itinerant
Frequency 27: 158.4075 MHz - itinerant


The Motorola RMM2050 (MURS radio - license free, but sold as an on-site business radio)

Defaults to:

Channel 1 - 154.5700 MHz - 67.0 Hz PL
Channel 2 - 154.6000 MHz - 67.0 Hz PL
Channel 3 - 151.8200 MHz - 67.0 Hz PL
Channel 4 - 151.8800 MHz - 67.0 Hz PL
Channel 5 - 151.9400 MHz - 67.0 Hz PL

Motorola also identifies frequency 1 as 154.570 MHz, frequency 2 as 154.600 MHz, frequency 3 as 151.820 MHz, frequency 4 as 151.880 MHz and frequency 5 as 151.940 MHz.

317

For Sale / Wanted / Barter / CRE 8900 (Alinco DR-135CB / DR-135DX) 11 meter CB 10 meter radio AM FM SSB CW

« on: February 14, 2020, 1440 UTC »

For sale is a lightly used CRE 8900 all-mode export radio.  This is a DIN-sized version of the AnyTone AT-5555 series (also known as the SS6900/Superstar 6900, Alpha 10 Max MA-1000, Maas DX5000, K-Po DX5000, Voyage BR-9000 and a dozen other models).  See below for the specifications:

http://cbradio.nl/cre/cre_8900.htm

The radio is in excellent condition and comes with original box, mounting brackets/hardware and microphone (with UP/DOWN and automatic squelch on/off on the mic).  All-mode AM FM LSB USB CW and PA modes.  Power output is adjustable for all modes.

25 watts SSB PEP
10-12 watts AM carrier
10-12 watts FM power
10-12 watts CW power

Features:

-Selectable clarifier steps 10 Hz, 100 Hz, 1 kHz or 10 kHz (change steps by simply pushing the clarifier knob in, very useful for SSB operation)
-10 meter mode (28.000 MHz - 29.700 MHz) and 11 meter mode (25.615-30.105 MHz)
-6 band radio with 60 channels per band, fully programmable channels
-Fully adjustable RF output power for all modes including SSB
-Adjustable RF gain
-Built-in echo control (echo level and time delay control)
-Five different display color modes
-Programmable emergency channel
-Dual watch
-Noise blanker and automatic noise limiter on/off (NB/ANL)
-AF noise filter (hi-cut)
-Fully adjustable roger beep duration and tone
- +10 kHz button
-Programmable scanning with scan list
-7 digit frequency display - shows the UK FM frequencies correctly (i.e. 27.78125 instead of 27.781 or 27.7812)
-Automatic SWR indication (shows SWR on transmit) option
-Power supply voltage indication (shows DC voltage on transmit) option

Right now the radio is programmed with the standard 6 band export channel plan with some extras, including the UK FM 27/81 channels as channels 21-60 on band F) the A channels for each band, several SSB freeband channels such as 27.440 MHz, 27.470 MHz, 27.500 MHz, etc. and several 10m FM frequencies

Computer programmable (computer programming is NOT required).  I have received numerous excellent signal reports on AM, FM and SSB mode.  Several ops commented that it sounded like I was talking on a "real" HF SSB ham rig.  The very fine tuning (10 Hz and 100 Hz steps) come in extremely handy when working SSB

This radio looks great in modern vehicles and can be dash-mounted with a DIN adapter.  Will be shipped with its original box/packaging and manual/documentation.  This radio is one of the first CRE 8900s to hit the market - I actually purchased it from a UK based radio distributor before the radio was even available in the USA. 

It's been sitting in my radio closet for a while now...unused.  I recently saw a new opened box version of this radio on sale on eBay for $300.  I'm asking $250 including shipping within the lower 48.  Send me a PM.

Thanks!

318

10/11 meters / Re: Man without a life....

« on: February 14, 2020, 1333 UTC »

Josh is right, 45auto. 

If the operator in question is throwing harmonics and/or spurs on other bands, it will gain the attention of the feds quicker.  The 4th harmonics of the CB band runs from 107.86 MHz (107.9 MHz effectively) to 109.62 MHz (109.6 MHz or 109.65 MHz effectively, the VOR band uses 50 kHz steps from 108.000 MHz to 117.950 MHz).  27.025 MHz (CB channel 6) drops its 4th harmonic right on 108.1 MHz, 5th harmonic on 135.125 MHz, 6th on 162.150 MHz...

The 4th harmonics can cause serious interference with the aircraft navigation service (VOR) in the 108.0 MHz - 117.95 MHz range.  The 5th harmonics can cause serious interference with aircraft communications in the 118.000 MHz - 136.975 MHz range, specifically 134.8 MHz - 137.025 MHz.   Since CB radio uses AM mode and the VHF aircraft band uses AM mode...the source of the interference will likely get noticed pretty quickly.  If he's running that dirty of a setup he's probably causing interference all over the bands.  Aircraft communications are considered "safety of life" communications and the FCC and FAA will get involved. 

All it takes is a few milliwatts (or even microwatts, depending on the antenna used and how close the transmitter is to air traffic) to cause issues with the VHF air band.   

Prior to the digital TV conversion, the obvious issue as far as CB harmonics go is that the 2nd harmonic of 27 MHz is right on TV channel 2 (54 MHz - 60 MHz) and AM signals cause massive interference to analog TV signals.  z

That aside, a strong AM CB signal can also get into all sorts of electronics (stereo systems, computer speakers, headphones, guitar amplifiers, PA systems, VCRs, entertainment systems, etc. etc.)  it's not uncommon for a strong AM CB signal to be heard coming out of a speaker (after all, all you need is a diode to act as a detector if the signal is strong enough). 

I did a series of tests a few years back with a home built 11 meter beacon transmitter.  It did in the 50-100 milliwatt range and was connected to a dipole antenna mounted in an attic.  It was a simple AM transmitter modulated with a 1000 Hz tone generator.  Crystal controlled on 27.500 MHz (for initial testing anyway, I eventually played with other frequencies - once I got my hands on a bunch of 26 MHz - 27 MHz crystals) it made a nice carrier signal with two tones 1 kHz up and 1 kHz down from center frequency 27.501 MHz and 27.499 MHz = perfect for doing range testing with a mobile radio in SSB mode. 

Anyway, the transmitter's 1 kHz tone could easily be heard coming out of the neighbor's hi-fi system's speakers and my roommate's computer's speakers.  Sooo...that got noticed pretty quick.  The installation of a low pass filter on the transmitter and several RF chokes on the speaker wire solved the problem. 

319

Other / Re: UNID 8000 LSB 2229 UTC 2017-03-18

« on: February 14, 2020, 1323 UTC »

8888.8 kHz and 8888.88 kHz are both super easy to remember frequencies.   Same with 6666.6 kHz (which is heavily used by peskies and freebanders in the Americas). 

Interesting to know that the South Africans are using 8888.88 kHz and 12352 kHz.  It wouldn't surprise me if they used 12345.6 kHz or 5678.9 kHz, etc. 

320

VHF/UHF Logs, including satellites and radiosondes / Re: 151.625 MHz Business Band Itinerant Analog FM vs. DMR Digital Voice 12 Feb 2020

« on: February 13, 2020, 2157 UTC »

Yep.  151.625, 151.955 and several others are included as the default out of the box channels for Motorola and Kenwood land mobile gear.  They’re basically the VHF versions of 464.500, 464.550, 467.925, 467.875, 467.850, 469.500, 469.550, etc.

DMR is affordable and encrypted DMR is relatively easy to implement.  Lots of users (construction companies included) seem to simply buy a massive lot of radios and use them on the factory default channels.  I know that local radio shops will often leave the radios on the factory default channels but change the CTCSS or DCS tone/code. 

For the end user, that turns into a “private channel”.  Same thing with DMR.

Crane Master - who is actually licensed for 151.625 among others, make extensive use of that frequency (with a PL tone, 167.9 Hz to be exact) for truck to truck chatter.  They’re licensed for 110 watts on 151.625 but only 45 watts on the other VHF frequencies on their license.  From what I’ve heard of them using 151.625, they are running 110 watts...

I’ve seen licenses authorized for a lot more than 100/110 watts on 151.625 and others.  I believe the American Red Cross is licensed for 110 watts PEP -on 151.625 and several other channels - base stations, mobiles and portable/temporary repeaters.  Similar licenses for temporary / itinerant systems exist with similar power levels....or even more than 110w.  Highest I’ve seen is 300w. 

The ARC is also authorized 125w PEP (500w ERP) on 27.490 MHz as part of the same license - WQMD985

https://wireless2.fcc.gov/UlsApp/UlsSearch/licenseFreqSum.jsp?licKey=3214188


Here’s another interesting one. 

https://wireless2.fcc.gov/UlsApp/UlsSearch/licenseFreqSum.jsp?licKey=4215560

321

VHF/UHF Logs, including satellites and radiosondes / Re: VHF Marine and NOAA distance

« on: February 13, 2020, 2153 UTC »

During ducting events the NOAA weather radio channels can get pretty crazy.  I’ve logged stations hundreds of miles away during very good band conditions. 

They’re de facto VHF beacons.  The only issue is the transmitters don’t all transmit the same output power, have the same antenna directionality or elevation...but all the info (including coverage maps, transmitter output power, etc.) can be found on the NOAA Weather Radio homepage. 

322

10/11 meters / Re: 11 meter private comms?

« on: February 13, 2020, 2150 UTC »

Exactly.  There’s a couple of these data link networks that send a packet every 2-3 seconds and it can get extremely annoying...it’s usually just strong enough of a signal to open the squelch (when listening to CSQ or carrier squelch mode of course). 

With 2 watts some of these systems actually get some impressive range.  Their antennas must be quite elevated. I’m in an urban area - the presumption is the more consistent data bursts on coming from a system with at least one antenna on top of a building somewhere.

323

10/11 meters / Re: 27.555

« on: February 13, 2020, 2145 UTC »

Ahhh yes.  Reminds me of “Radio Blue Waffle” and “Number 3 Repeater” on 27.385 LSB and 27.555 USB just yakking away for hours.

Oh, and then there’s this guy:

https://youtu.be/h0HxYBGvD9g

Apparently he got The Knock eventually....

324

Peskies / Re: New England Fishermen 6263.5 USB 2005 UTC 12 Feb 2020

« on: February 13, 2020, 1446 UTC »

The Maine Based Bahstads Strike Again? 

325

Utility / Re: English EU network 6301 USB 2238 UTC 10 Feb 2020

« on: February 13, 2020, 1445 UTC »

...
I don't know if these were theirs or strangers ride on the channel + / _ 2kHz carrier.
...

What do you mean exactly?  Carriers were popping up +/- 2 kHz from the 6301 kHz center frequency?  That would make sense if they're tuning up transmitters, tuning antennas, etc. 

326

VHF/UHF Logs, including satellites and radiosondes / Re: 151.625 MHz Business Band Itinerant Analog FM vs. DMR Digital Voice 12 Feb 2020

« on: February 13, 2020, 1439 UTC »

Could be cops doing a stakeout.

They're partial to UHF and 700/800 MHz  - plus now their 800 MHz trunking system is 100% encrypted.  Prior to the switch over to 100% encryption I could hear all the "tac" talkgroups (channels) - which were (and probably still are) heavily used as "party line" channels for various task forces, generally associated with narcotics and vice cops, often with informal CB-like chatter and very personal information being shared over the air.  One time they had a patch from what sounded like an analog wire or surveillance feed re-transmitted over one of these tac channels so that the "roving" officers outside the short range of the wire/bug could hear the audio. 

There's a massive demolition project going on in the downtown area, with several contractors and subcontractors involved...I caught a glimpse of one of the radios being used and it had a distinctively VHF antenna.  Compared to most on-site construction radios (which are UHF) it was noticeable.  I was driving by and didn't get that good of a look at the radio but it was a Motorola and probably a MotoTRBO model, which would explain the DMR traffic heard on 151.625 MHz.

One of the subcontractors ( https://www.radioreference.com/apps/db/?fccCallsign=WPNU205 )  uses 151.6250 in addition to 151.5050, 151.5125, 158.4000 and 158.4075.  They use 151.625 as their truck-to-truck channel, with very high power mobiles.  They use analog only though. 

327

10/11 meters / Re: Man without a life....

« on: February 13, 2020, 1426 UTC »

There was a guy in the Omaha/Counciltucky region with a lot of spurs that went to the air band as well as keying up 2m repeaters. This is the late 80s or so. So the local HAMs got together and found him, turned him in to fcc after he refused to do something about his radio hygiene with gentle HAM persuasion, and the fedz took care of the issue. He was one of those guys with a suburban that had a 10kw cb in it and a 11m antenna with a coil like a car coil spring. Now those guys are all over.

Bonus points if he was using a DAVE MADE amplifier.  The massive coil antennas + 10s of kilowatts CB crowd can be found driving beat up old Cadillacs (at least in my area) as well as Suburbans and various pickups.   Those huge coil antennas can be found on regular semi trucks too - no doubt because the truck has a very high power CB setup installed. 

http://www.davemade.mobi/



I remember talking to one of the local CBers (face to face, I ran into him at a hamfest, go figure) about one of the more infamous local AM CB guys - apparently there was another operator who had a similar set up - peeked and tooned radio with modulation limiter removed, power mic and several amplifiers without any sort of LPF or filtering of any kind employed.  He spewed spurs all over 10 meters and harmonics into the VHF aircraft band.  The 4th harmonic happened to land right on one of the VOR radio navigation frequencies used by the local airport. Needless to say, he got "the knock" pretty quick. 

328

10/11 meters / Re: 27.555

« on: February 13, 2020, 1423 UTC »

I've heard about the 27.555 MHz USB jammers in Europe and the UK as well.  I've never actually heard them myself during band openings to Europe, even when the band is very open to the UK/Ireland area and I can hear UK FM CB activity (and even work UK stations on the UK FM channels when the band is really open!) 

26.285 MHz USB is certainly an option for alternate calling frequency.  26 MHz is popular in Poland and elsewhere.  Here in the Americas, 26.555 MHz LSB, 26.225 MHz USB, 26.230 MHz USB, 26.235 MHz USB and 26.500 MHz LSB are popular SSB calling frequencies for Spanish speaking stations on 26 MHz.  There are numerous 27 MHz SSB calling frequencies for Spanish speaking stations, 27.455 MHz USB being the big one. 

26.285 MHz is channel 19 "down two bands" (see also: 26.735 MHz, 27.635 MHz and 25.835 MHz).  In the US, it is common for trucking companies, logging companies, etc. to use 6-band export radios and flip the band switch up and down from channel 19 to access a "clear channel" or even a "company channel".  I have heard trucking company chatter on 25.835 MHz, 26.285 MHz, 26.735 MHz and 27.635 MHz when the band is open, all in AM mode.  There appears to be a local or local-ish logging company that uses 25.835 MHz (channel 19 on Band A) for truck-to-truck comms as well.  The lower channels upper part of the 25 MHz band and the 26 MHz band is also popular with hunting clubs and other users in the USA and taxi cab dispatchers in Latin America.  I know that European 11m operators have had to deal with the QRM from Russian taxi dispatchers when the band is open, Americans have similar issues with Latin American taxis.  The Spanish speaking taxi dispatchers almost exclusively use AM mode though, compared to the FM mode used by the Russians.

Other than that, 26.285 USB could certainly be used.  27.555 USB is just a lot more well-known, especially in the USA.  Same with 27.385 LSB.

329

10/11 meters / Re: 11 meter private comms?

« on: February 13, 2020, 1415 UTC »

45auto,

Yep, the data bursts on MURS could be any number of things.  In my area, there are several telemetry systems that use the MURS channels.  They appear be related to industrial sites located 1-2 miles away.  I know that dog collars and hunting dog tracking systems use the MURS channels as do the driveway alert and security alert systems.  There are numerous other systems that use the MURS channels.  Luckily, you will be able to program in a CTCSS or DCS tone/code for your radios and those will filter out the annoying interference. 

I sent you a PM as well with more detailed information on how to implement CTCSS to eliminate the interference on the MURS frequencies as well as other detailed information for your purposes. 

330

VHF/UHF Logs, including satellites and radiosondes / 151.625 MHz Business Band Itinerant Analog FM vs. DMR Digital Voice 12 Feb 2020

« on: February 12, 2020, 1808 UTC »

Around 12:30 PM local time, receiving equipment is a TYT TH-9000D VHF mobile transceiver with a Browning BR-168-BS 1/2 wave VHF antenna with a Chevrolet sedan ground plane.  Tuned to 151.6250 MHz listening to two different users running analog FM (narrow FM, NFM, NBFM) 11 kHz bandwidth analog voice, one of the users appeared to be a construction crew and the other sounded like surveyors.  A strong DMR signal (full scale) obliterated the analog traffic on frequency for several seconds at a time.  I've noticed multiple analog users of the VHF itinerant business frequencies, but 151.625 MHz is the only one I've heard DMR digital voice on.  It's not P25, but DMR aka Motorola TRBO or MotoTRBO.

VHF itinerants:

151.5050 MHz
151.5125 MHz
151.6250 MHz
151.7000 MHz
151.7600 MHz
154.5275 MHz
158.4000 MHz
158.4075 MHz

151.625 is by far the most popular of the eight frequencies.  If you include the five license-free MURS channels 151.820 MHz, 151.880 MHz, 151.940 MHz, 154.570 MHz and 154.600 MHz along with 151.955 MHz (which isn't technically an itinerant channel), the number of monitoring targets increases significantly.