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Messages - R4002

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General Radio Discussion / Re: Estonian electronic warfare
« on: August 01, 2019, 1820 UTC »

The US bought thousands of VHF-FM handheld and mobile radios to supply to the Afghan National Army (ANA). 


Read the whole document if you have the time, but check out page 9 of the PDF. [Key U.S.-Funded Communications Equipment for the Afghan National Defense and Security Forces (ANDSF)]

It lists the models of the radios purchased as well as the frequency bands.  The Motorola GM360 is known as the Motorola CDM1250 in the US.  VHF high band (136-174 MHz) use for police and government services. 

The radios purchased include the Datron PRC-1070 VHF handheld tactical radio (30.000-87.975 MHz in 25 kHz steps), Datron HH7700 VHF handheld tactical radio (30.000 MHz to 87.975 MHz in 25 kHz steps), the Datron PRC-1077 manpack/mobile vehicle mounted tactical radio (basically an improved PRC-77, same size and uses same accessories/antenna, also 30-88 MHz in 25 kHz steps).  All three of these radios use the standard 150 Hz CTCSS tone squelch system.  A total of 75,256 of those radios were purchased.  All three of them are the standard VHF-FM combat net radio.  No frequency hopping or encryption.  Yes, they did also purchase multiband VHF/UHF radios and HF radios, but the vast majority of them are basically upgraded PRC-77s. 

PRC-1070:  https://jds-productions.com/Video/Datron/assets/DataSheets/DTR_PRC1070-5-hres.pdf

PRC-1077: https://static1.squarespace.com/static/5a5fc6241f318d2cee774450/t/5aa71bb1c83025cc85f86cb1/1520901043047/Datron_PRC1077.pdf

HH-7700: https://jds-productions.com/Video/Datron/assets/DataSheets/DTR_HH7700ds5-10.pdf

The AR-8200 Mark III is the AOR AR8200MkIII scanner/communications receiver for signals intelligence/low-level voice intercept work.  Looks like they just bought them from Universal Radio.  The AR8200 is a handheld radio that does 500 kHz to 3 GHz without any gaps, custom frequency/channel steps, and has tons of other features.  It's ideal for listening to the bad guys' radio comms in Afghanistan - which include various HF radios for long-range comms but for tactical use they favor VHF high band handhelds (read: 2 meter HTs).  My understanding is that there's at least some limited use of 26-28 MHz/11 meter equipment as well. 

I also believe that the US know that at least some of the radio gear provided to the Afghans will somehow or another end up in the hands of the bad guys so its probably a good thing they're not equipped with frequency hopping or voice encryption. 

I've seen images of US military signals intelligence guys using the AR8200 scanner/receiver in Afghanistan. 


General Radio Discussion / Re: Estonian electronic warfare
« on: August 01, 2019, 1618 UTC »
Awesome link, Chris.  Iím still browsing through all the gear these guys used.  I wonder how much equipment like this is currently being used in the conflict in Ukraine.

The R-123 HF/VHF FM military land mobile / combat net radio 20-51.5 MHz in 25 kHz steps seems to be their version of the VRC-12 and similar systems (30-76 MHz in 50 kHz steps and then 30-88 MHz in 25 kHz steps)


The R-148 manpack portable transceiver seems like a cross between the PRC-25/PRC-77 and PRC-68 series...37 MHz to 51.95 MHz / 37-52 MHz in 50 kHz steps, but the R-158 seems like it would be used closer to modern day - almost exactly like the improved PRC-77 clones like the PRC-1077.  30.000 MHz to 79.975 MHz in 25 kHz steps is legit.  I wonder if the Russian combat net FM radios use the 150 Hz CTCSS tone as well.

More of the same this morning, August 1st, 2019 08/01/2019 - 


VHF DX NOAA Weather Radio 1 August 2019 Part 1 of 2



VHF DX NOAA Weather Radio 1 August 2019 Part 2 of 2

More nice catches, especially the VHF marine channel 14 traffic on 156.700 MHz.  I imagine there is some serious marine coast VHF (and MF/HF!) stations in your area.  There are plenty of licensed MC stations on the 156.050 MHz - 157.425 MHz band, but I'm sure there are also plenty of folks with VHF marine radios installed in their homes/businesses/marinas as base stations with high gain antennas.

Here are the videos for this morning's commute:




This morning yielded the usual mess on 162.450 MHz and 162.550 MHz, but I did get positive IDs for WNG586 out of Henderson, NC on 162.500 MHz and KJY86 on 162.525 MHz out of Halifax, VA as well.  162.450 was really messy, usually KZZ28 wins.  Yesterday evening KZZ28 was having technical difficulties [see: https://www.youtube.com/watch?v=0wpea6S3t8M] but this morning they appeared to be back in service. 

1107 UTC 30 July 2019: Whistling then "hey, you got me?" then the other guy came back.  Asked if he worked all night, other guy said had a paycheck. First guy said he can get out of there by 2 o'clock he can make the tide, whatever he has he has.  Asked if he talked to John, he said no but he just whistled him (I assume on another frequency?).   One guy (I lost track which) said I'm gonna give John a whistle here, I'll try him on the sideband.  Done around 1112 UTC.

Sounds like at least some of these boats have multiple radios standing by on multiple frequencies  8)

Love it.  These guys are all over the place.  Somebody programmed a bunch of out-of-band frequencies in their radios.  "sideband" might be code-word for back-channel or alternate channel.  Wouldn't surprise me if they have frequencies in the 2-3 MHz region or the 4-5 MHz portions as well. 

I remember watching 'Deadliest Catch' years ago and noticing the radios in one of the boat's wheelhouses.  They had several VHF marine radios of various types, including the up-to-date versions with DSC and built-in GPS as well as the bare-bones regular old just-does-FM-voice VHF marine radios.  I noticed a HF-SSB radio (at least one) and what appeared to be a Galaxy or Ranger/RCI export radio/CB radio.  They had weatherfax RX and NAVTEX RX gear too. 

These out of band frequencies are just like freeband CB to these guys. 

The whistle-into-the-mic "calling" method is also heavily favored by the Spanish and Portuguese speaking pescadore nets heard on [list of dozens of frequencies here].[/list]

Interesting note on the 4030 kHz USB frequency before switching up to 6230 kHz USB.  They might have a 8 MHz frequency as well.  I know I've heard Caribbean yachtman's nets / cruising nets on 4003 kHz USB too, similar format and content to the various 6 MHz and 8 MHz yacht and sailing nets, so perhaps 4003 kHz USB is the 4 MHz frequency for another one of these nets. 

1129 UTC sounds close enough to 30 past the hour to make it a schedule.  Selective calling in the sense that they whistle into the mic to get the other guy's attention (who probably has his radio's volume turned down until the scheduled time).   

During the 3-4 years I've been paying attention to this, I've never heard WXK65 here.
With the rare exceptions, west of here just doesn't happen

Ok forget that! I started not to post this or remove it, never say never. Weird, very weird indeed!

Very nice.  I think you're in a better location for ducting than I am, since you have more over-water propagation paths near you.  Here's today's catch:


WNG586 on 162.500 MHz with loud and clear ID...162.450 was very messy, at points it almost sounded like three different stations were on the frequency at the same time.  Given the FM capture effect, this would indicate that the signal strengths were very close to identical.  162.550 was even worse, at least two stations QRMing each other to the point that very little could be made out as far as trying to ID them...my presumption is that it's the usual suspects - KHB36 and KHB37 fighting it out.

For east coast drone enthusiasts;
323.000 (Boston Center sector drones use to get clearance for Adirondack operating)

Cobra, Python, Apex callsigns are drones

Are these frequencies used up and down the East Coast for drone ops? Or just the New England / Northeast?

No sign of WXK65 (1000w out of Richmond City) on 162.475 MHz in Virginia Beach? Just KIG77. 

10/11 meters / Re: 11 meters is active 0320 UTC 25 July 2019
« on: July 28, 2019, 1727 UTC »
Probably close to a dollar to a watt, if you count the cost of buying the vehicle with the full size V8, all the additional alternators, driver amplifier l, secondary driver (if applicable) and final amplifier.  Plus you have all the wiring, shielding, capacitors and everything else for running high-amperage DC safely.  Then you have the custom feedline and antenna setup....my understanding is that some of these guys run custom AC powered setups instead of DC, but I donít know any specifics.

Weíre also neglecting the AC powered base stations with several 220/240 volt powered amplifiers or DC powered amps with custom built power supplies for base station usage. 

Amateur Radio / Re: 2m VHF band to be surrendered to aviation?
« on: July 26, 2019, 1241 UTC »
Europe switched to the 8.33 kHz spacing a bit ago now.  I don't really understand why they picked 8.33 kHz.  They could have done 12.5 kHz (increase 760 channels to 1520 channels) but instead they divided 25 kHz by 3 to get 8.33 kHz channeling, for 2280 channels.  Of course, this causes all sorts of weird rounding off of the frequencies when read over the air.  They would have been better off with doing 5 kHz spacing at this point (since most frequencies are apparently rounded off to the nearest 1xx.xx0 or 1xx.xx5 frequency when read over the air.  I know the AM emission is 6K00A3E (so 6 kHz bandwidth).   

But, instead, they did 8.33 kHz for Europe.  I know most the of the rest of the world still does 25 kHz spacing for VHF airband.  Expanding the band from 136.975 MHz (or is it 136.98333 MHz, rounded up to 136.985 MHz...or 136.99166 MHz, rounded down to 136.990 MHz???  We'll say 137.000 MHz for the sake of simplicity - 137 MHz to 144 MHz that's an additional 7 MHz of spectrum (to be shared with satcom and other users...the same issue with sharing it with 2-meters, or "sharing" it with 2 meters, I should say). 

Expanding the band from 136.975 MHz up to 144.000 MHz (or 143.975 MHz) at 25 kHz channel spacing (or 40 channels per MHz) would give an additional 280 channels, or 279 channels.  8.33 kHz spacing gives 120 channels per MHz, so that would be an additional 839 channels or 840 channels, depending on how big of a guard band you want before you get to 144.000 MHz. 

The United States military makes extensive use of 137-144 MHz and 148-150.8 MHz for air-to-air communications as well as military land mobile comms and other things, including VHF SATCOM purposes and other niche uses.  Military air-to-air use AM mode with 25 kHz channel spacing while land mobile and other purposes use 12.5 kHz channel spacing and FM voice, Project 25 digital voice or other digital modes. 

The VHF air band was originally (back in WWII) 100 MHz to 156 MHz with weird spacing, maybe 40 kHz channels?  Then it was changed to 108 MHz to 132 MHz, then 135 MHz, then 136 MHz, then 136.975 MHz (if my memory serves me correctly)...with channel spacing getting progressively smaller (100 kHz, then 50 kHz, then 25 kHz...).   Because of the original 100-156 MHz VHF-AM band, the US military has continued to include the band above 137 MHz in its VHF air radios.  Most of them do 108.000 MHz - 151.975 MHz I believe, including the 2 meter portion 144-148 MHz. 

The 2 meter band is one of the busiest amateur bands in VHF/UHF, if not the busiest, at least in the USA.  I know in a lot of places its 144-146 MHz and not 144-148 MHz.  There are plenty of users of the 137-144 MHz region and 148-150.775 MHz region (in the USA, once you get to 150.775 MHz, you get into the Part 90 land mobile radio services, with 7.5 kHz steps). 
The whole bandwidth is bigger than channel spacing seems to work with the VHF and UHF land mobile narrowbanding completed back in 2013.  12 kHz wide signals on 7.5 kHz channels.  Of course systems aren't supposed to be put right next to each other in frequency, but in practice they are.  In my local area, for example, each local public school has its own VHF repeater.  They're low power on-site repeaters (anywhere from 10 watts to 50 watts output power) but they actually carry quite a distance.  These repeaters are literally right next to each other in the band plan (152.9000 MHz, then 152.9075 MHz, or 152.3900 MHz, then 152.3975 MHz, then 152.4050 MHz, then 152.4125 MHz, then 152.4200 MHz, then 152.4275 MHz, literally every channel step has an active repeater on it, some of them having more than one.  152.3000 MHz is used by two different schools, a local taxicab company and a local quarry...and the adjacent frequencies 152.2925 MHz and 152.3075 MHz are also both active. It's done by putting the adjacent-channel repeater as far away as possible and using CTCSS and DCS tone squelch systems.  I know that's not possible with AM voice on the air band, of course.  With FM you also have the advantage of the capture effect, whereas multiple AM signals just mix with each other on the receiver. 

The local National Guard uses a portable Project 25 digital system (portable system) with several frequencies between 148.000 MHz and 150.800 MHz used - including 150.800 MHz itself, even though that's technically allocated for land mobile, 150.775 MHz, 150.7825 MHz, 150.790 MHz, 150.7975 MHz, 150.805 MHz, 150.8125 MHz, etc etc.  There are some special rules for 150.775 MHz and 150.790 MHz given the fact that they're in the "boundary area" between military AM aircraft and FM/P25 voice band and the beginning of the FCC allocated land mobile VHF band.   Like most things, the military can use the frequencies they want/need even if those frequencies fall within the civilian land mobile bands...provided there isn't a major interference issue.  This is also the case in the 30-50 MHz region...but I digress. 

Since aircraft radio communications are certainly what I would consider "safety of life" communications...I don't know if a "secondary" allocation is really possible in the real world.  Maybe increase the band from 137 MHz up to 144 MHz?  These frequencies aren't empty, and neither is 144-146 MHz / 144-148 MHz.  I don't like it. 

Nice catch on the late night tropo with WXM80 on 162.475 MHz.  Hopefully this morningís commute will yield some
 more logs, if the propagation is good Iíll post another video.

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