Archive for the ‘hf’ Category

Weak-Signal Performance of Common Modulation Formats

At first, I was just looking around on the web for some simple Rules of Thumb that compare the weak-signal performance of commonly used analog and digital modulation types. I was mostly focused on FT8 and FT4 but I also wanted to compare SSB and CW. I failed to find a simple comparison of these modes but I did find a number of good articles that compared some but not all of them. This article is my attempt to aggregate the available information into something easy to understand.

Disclaimers

I decided to leverage the work of others and to not try deriving everything from basic principles. I am telling myself that I am perfectly capable of doing the analysis but that I would never find the time to actually complete it. (Yeah, that’s my story, and I’m sticking to it.) Where the articles disagree, I tried to identify which one(s) had the most convincing analysis or rationale and used those values.

My goal is to compare common modulation types primarily in terms of weak-signal performance. This means focusing on how well a signal can be detected with low signal-to-noise ratio (SNR). I have ignored other factors, such as signal fading, frequency drift, multipath distortion, etc. Also ignored are factors such as the information rate provided by the modulation type and the required signal bandwidth. This is focused on having the ability to pass just enough info to make the contact.

Literature Survey

Searching the internet provided me with a number of good articles that have examined this topic, listed below in the References section. My approach is to compare the results of these articles and aggregate them into a concise summary. These minimum SNR values are listed in the table shown below, along with my aggregated conclusions in the righthand column.

Most of these articles presented SNR data in terms of a 2500 Hz bandwidth, with the goal of providing an easy comparison between modulation types. SSB is the widest signal discussed, and it roughly fits into a 2500 Hz bandwidth, which is often the IF bandwidth of the receiver being used. Some authors make this explicit by tagging this SNR as SNR2500.  It is common practice in communications work to normalize the bandwidth to 1 Hz, which indicates the modulation’s bandwidth efficiency. However, we’ll stick with SNR2500.

I started with the article by PA3FWM [Ref 1], which provides a look at many of the modes I was interested in comparing. Unfortunately, this article does not include FT4 and FT8. N6MW [Ref 2] has a good treatment of FT4 and FT8 as well as minimum SNR values for SSB and CW. These lined up well with the PA3FWM values, so that was a good sign. N6MW referenced the foundational article about FT4 and FT8, published in QEX, written by the FT4 and FT8 developers [Ref 3]. The KB9II article [Ref 4] focuses on VHF weak-signal performance and provides minimum SNRs for SSB, RTTY, CW, and PSK31. He introduces the concepts of SNR (average) and SNR (peak). I used the SNR (average) numbers in the table. The KF6HI [Ref 5] article provided another set of SNR values that lined up pretty well. Finally, I came across a presentation by K0LB and KK4SNO [Ref 6] that includes a slide summarizing SNR performance. Because it is slideware, it does not include much about the sources of their numbers, but it seems useful to include them in the table.

Table: A compilation of minimum SNR2500 levels in dB for various modes.

The authors have somewhat different approaches to determining their SNR2500 numbers, mostly related to the assumptions used. You may want to read through these papers to gain a better understanding of the fine points. Overall, there is good alignment on results, with a few exceptions.

SSB

The single-sideband SNR2500 values are a mix of 10 dB and 6 dB. Frankly, I think 10 dB is a bit high for “minimum SNR” because I’ve spent quite a bit of time making weak-signal VHF/UHF contacts with the signal right at the noise level. I’ve squeezed out radio contacts with SNR much less than 10 dB. I looked at the rationale supplied in the articles for this value and it is mostly just assumed. So I went with my own experience and chose something smaller, 6 dB, aligning with KB9II and KF6HI. Even this number might be a bit conservative.

RTTY

I found only four values for RTTY, and they vary quite a bit. After studying the articles, I judged KB9II to have the best justification, so I went with -9 dB. I suspect that the actual decode performance may vary depending on the type and quality of the detector.

CW

The SNR2500 numbers for CW varied significantly, over a range of 10 dB. One way to estimate CW performance is to use the bandwidth of the receiver and compare it to 2500 Hz. Using a typical CW filter bandwidth of 200 Hz, SNR2500 = 10 log (200/2500) = -11.0 dB. However, it is well-known that the human ear/brain combination provides additional signal processing. The classic article by W2RS [Ref 7] covers this topic quite well. Using actual on-the-air tests, the article explains that the skill of the operator can introduce a variation of 3 to 6 dB. Another interesting note is that if the operator knows in advance the type of information they are expecting (such as the callsign of the other station), it provides a 3-dB advantage.

We can and probably will debate the SNR2500 value for CW until the cows come home, but I decided to adopt -12 dB in the right-hand column. This is probably conservative for a highly skilled operator.

FT8, FT4

For FT8 and FT4, I used the N6MW values, which come directly from the FT4 and FT8 paper [Ref 3]. I rounded off to the nearest decibel to be consistent with the rest of the column.

JT65

The JT65 values are quite consistent. An article by K1JT [Ref 8] says JT65 SNR is “roughly -28 to -24 dB in 2500 Hz,” so I put -24 dB in the righthand column.

WSPR

WSPR is a popular beacon mode and the king of weak-signal reception. Signal reports are collected worldwide and shared via WSPRnet.org. WSPR performance will vary depending on the specific settings used on the software and we have some variation in the table. The K1JT & W1BW article [Ref 9] says, “The WSPR protocol is effective at signal-to-noise ratios as low as –28 dB in a 2500 Hz bandwidth, some 10 to 15 dB below the threshold of audibility.” So I used -28 dB in the aggregated column.

Conclusions

The rightmost column in the table provides a reasonable comparison of the listed modulation types. I don’t claim that the values are perfect, but they should be helpful in understanding the performance of these modes. These data show that SSB is the least sensitive mode, followed by RTTY and PSK31. As mentioned earlier, the CW number is open to debate but it performs better than RTTY and PSK31. This brings us to FT4 and FT8, which are commonly used WSJT protocols with reasonable throughput. (FT4 and FT8 using 7.5 and 15-second transmit/receive intervals.) JT65 operates at lower SNR, but it is really in a different category, It is designed for Earth-Moon-Earth contacts, using one-minute intervals. WSPR is also unique as a beaconing system and not designed for two-way radio contacts, but it does have the best SNR performance on the list.

When using this data, keep in mind that most of these modes degrade slowly so there may not be a sharp cutoff at an exact signal level. The values are Rules of Thumb, accurate to within a few dB.

Thanks to Jim/K5ND and Bob/WØBV for reviewing this article and providing feedback.

73 Bob K0NR

References

  1. Signal/noise ratio of digital amateur modes – Pieter-Tjerk de Boer, PA3FWM

  2. FT8 Modulation and Decoding – A Dive into SNR interpretation N6MW

  3. The FT4 and FT8 Communication Protocols – Steve Franke, K9AN- Bill Somerville, G4WJS – Joe Taylor, K1JT

  4. A Comparison of Common Digital Modes for Weak Signal VHF Communications – John Matz, KB9II

  5. Signal to Noise Ratio, definition and application to Radio Communications – KF6HI

  6. Digital Modes in Amateur Radio – Larry, K0LB and Scott, KK4SNO

  7. The Weak-Signal Capability of the Human Ear – Ray Soifer, W2RS

  8. EME with JT65 – Joe Taylor, K1JT

  9. WSPRing Around the World – Joe Taylor, K1JT, and Bruce Walker, W1BW

The post Weak-Signal Performance of Common Modulation Formats appeared first on The KØNR Radio Site.

Chasing States

Sometimes, I just need a reason to get on the air. Specific operating goals can help with this, whatever form they take, including operating awards. One of the first awards I earned many years ago was Worked All States (WAS). The mixed WAS is not that difficult because you can use any of the HF bands to make the contacts. Some bands are better for close-in states while others are better for long distances. Do a lot of operating, and you’ll eventually earn WAS. And it is fun to chase states.

Six Meter WAS

A few months ago, I looked at my Logbook of The World (LoTW) stats and noticed that I was one state shy of having WAS on 6 meters. I was not working towards this objective, but I was making a lot of contacts on six, trying to work countries and grids. The state I was missing was Utah, which is adjacent to my state of Colorado. I know I had worked Utah before, but I didn’t have it confirmed. Utah is not that easy to work from my location, because the populated areas of the state are in a dead zone: too far away for tropo propagation but too close for sporadic-e. Once I realized I only needed Utah, I kept watch for Utah stations showed up on 6 meters. Soon, I worked KI7MD using meteor scatter and asked him to confirm the contact in LoTW. OK, there you g, I had WAS on 6 meters. I consider this a real accomplishment, one that took many years.

Chasing States By Band

Well, of course, it did not stop there. Another review of my LoTW results by state and band revealed that I already had WAS on 20 meters. I patted myself on the back for that accomplishment, even though I just stumbled across it. Then I noticed I had 43 states on 40 meters. Hmm, that should not be too difficult to complete because 40m propagation covers the US quite well. Alaska and Hawaii were both already confirmed so the challenge was filling in the missing lower 48 states. I’ve been doing quite a bit of FT8 operating lately, so I set JTAlert up to alert me when any of the states I needed were received on 40 meters. Whenever they popped up, I’d make it a point to work them, if possible. Soon, the missing states were filled in, and I had achieved WAS on 40m. Technically, I have the confirmations in LoTW (good enough for me), but I have not applied to have the award issued. Well, what band should I pursue next? I was a latecomer to the 30-meter band, making my first contact on that band in Feb 2024. However, I have learned to really like it with its propagation characteristics being an interesting mix of stateside and DX. I had about 30 states confirmed on 30m, so I figured it would not take too long to fill in the blanks. Again, I used FT8 aided by JTAlert to keep watch for the states I needed. I wasn’t completely zoned in on working these states…usually, I was on the air for other reasons, but when JTAlert told me there was a WAS contact to be had, I grabbed it. Right now, I have 49 states confirmed on 30m, with Delaware being the only one missing. Now, someone out there is thinking, “Don’t pursue WAS one band at a time; go for them all at once!” That probably would be more efficient, but that’s not what I am after. I just like having a few operating goals in front of me to focus my efforts and pursuing states on a single band fits that just fine.

WAS Score Card

Here’s a snapshot of my WAS numbers today, from LoTW. After I finish up 30m, I will probably focus on 15m or 10m. I tend to be on those bands anyway for chasing DX. On those bands, I seem to be missing the closer in states with lower population density such as Kansas, North Dakota, Nebraska, New Mexico, and Utah. This is predictable with the longer F2 propagation normally found on those bands. I don’t know that I’ll ever get WAS on 2m and I am more focused on VUCC for that band. Note that I have 4 states on 70cm: Arizona, Colorado, New Mexico and Wyoming. I am a bit surprised by that. Anyway, if you are looking for a reason to get on the air, chasing states might be interesting. Remember, it’s all about having fun messing around with radio. 73 Bob K0NR The post Chasing States appeared first on The KØNR Radio Site.

VP2V/K0NR: Another Slacker DXpedition

Operating from countries outside the US can be a lot of fun. I just completed another Slacker DXpedition, this time to the British Virgin Islands. The formula for this type of operation is simple: identify an interesting vacation spot that is also considered DX, travel there with friends and family, take along some compact radio gear, and get on the air. Photo from VP2V operating position for K0NR and K0JJW.A key point is not to overdo the radio operating, or the friends and family will veto any radio activity on future trips. This was not a super-gonzo turbo-charged DXpedition. I just worked in some radio action in between snorkeling and exploring the island. This is referred to as a “holiday style” DXpedition, or maybe it’s just the slacker approach.

VP2V British Virgin Islands

The idea for this trip originated with a group of friends who often travel together to fun places, often an island in the Caribbean. BVI had been on our list for a while, and we had a trip planned back in 2020, but the COVID-19 pandemic caused us to cancel it at the last minute. It has taken us some time to get a plan back together, but here we are doing the trip five years later.

When a travel opportunity like this surfaces, I check out the implications of amateur radio licensing for that country. For a US radio amateur (and probably most other countries), getting a radio license for VP2V is easy. The Telecommunications Regulatory Commission (TRC) website has clear instructions on how to apply. Joyce/K0JJW and I filled out a form, provided copies of our passports and FCC licenses, and paid a $20 license fee. This did require a trip to a notary public to have these documents notarized. My friend, Paul/KF9EY was on the trip so he also obtained his VP2V license.

Location

We rented a fantastic house (Ana Capri Estate) on the north side of the island of Tortola. This house has a great view out over the water. Tortola is the main island of the BVI, and international flights are available at the airport on the east end.

location of ana capri on Tortola
Ana Capri is located on the northeast side of BVI, on Tortola Island.

The Ham Station

Joyce VP2V/K0JJW is working on a pileup on SSB.

We took along our usual portable ham station, with a few updates. Our Yaesu FT-991 has served us well for POTA, SOTA, and island activations in the past, so it is our go-to radio for this sort of operation. The key features include a 100-watt RF output, a built-in sound card for digital modes, an internal antenna tuner, and a small enough size. This radio has HF plus 6m, 2m, and 70cm, which can be handy. Add a compact Samlex switching power supply, and we are ready. Recently, we have moved away from using End-fed Halfwave (EFHW) antennas and started using an End-Fed-Random Wire (EFRW), also called an End-Fed Long Wire (EFLW). The difference is subtle but important. The EFRW uses a wire length that is intentionally not resonant on any band, fed by 9:1 UNUN matching device. This setup radiates well over a range of frequencies but does require an antenna tuner because it is not a consistent 50-ohm impedance on all bands. I’ve found this to be a reasonable tradeoff between quick-changing band coverage and performance.

The Palomar Engineering Bullet-9 (9:1 UNUN) provides matching at the end of the wire antenna.

For this trip, we used the Palomar Engineers Bullet-9 UNUN, rated for 500 watts PEP. A variety of wire lengths can be used with this approach, with longer wires supporting lower frequencies. The 34-foot wire element supports operating on all bands from 40m to 6m, supported by the SOTABeams Travel Mast. The Travel Mast compacts to just 26.5 inches and extends to 32 feet. Actually, I modified the top of the mast to make it stronger, so the net height is closer to 29 feet. The end-fed wire antenna is almost vertical when deployed in this manner.

In past portable efforts, I’ve encountered issues with inconsistent antenna match and RF getting back into the FT-991. I checked this out carefully before the trip and adopted some mitigation practices that seem to help. First, I made sure the wire antenna could be supported almost vertically. This is not a strict requirement but it seems to help with getting a good match across all bands. I don’t use a counterpoise, but I do have 50 feet of RG-8X coax lying on the ground, which provides a bit of counterpoise. This length of coax also lets me keep the antenna separated from the transceiver by a reasonable distance, reducing the opportunity for RF to get back into the transceiver. Finally, I use a short USB cable, with ferrite cores on both ends, to connect my notebook PC to the FT-911. In the past, the USB connection between my PC and radio sometimes quit. These precautions appear to have paid off, as the station worked without any issues.

The SOTABeams Travel Mast does a great job supporting the endfed wire antenna.

Operating

We set up the station outdoors under a covered patio to enjoy the fantastic view and (mostly) great weather while operating. This was not optimal, as we did get chased inside a few times when rain squalls moved in. They never lasted long, so I think the tradeoff was worth it.

The propagation on the HF bands has been quite good lately, and we continued to enjoy that while in BVI. We did not have much of an operating plan (“slacker style”) but intended to operate on the higher HF bands, mostly 20m and higher, using SSB, FT8, and FT4. Bob/W0BV pointed out that VP2V is somewhat rare, showing up at number 114 on the ClubLog Most Wanted List. Sure enough, whenever we called CQ, we were greeted with a nice pileup.

Paul VP2V/KF9EY working stations on digital (FT8, FT4).

My VP2V/K0NR log has 1030 contacts, including 61 DXCC entities and 23 CQ Zones. I focused mostly on keeping the run rate up and just making contacts. About half of the Qs were with the US. The logs of VP2V/K0JJW and VP2V/KF9EY are not included in these numbers. I tended to stay on the higher bands as they were working quite well.

VP2V/K0NR Log
Band Phone Dig Total  %
30       0  79    79  8
20       0  46    46  4
17       0  90    90  9
15       0 161   161 16
12      44 349   393 38
10       0 260   260 25
 2       1   0     1  0
--    ---- ---   --- --
Total   45 985 1,030 100

As you can see from the numbers above, I made a lot of digital contacts (FT8/FT4). I found FT8 to be slow, and the normal FT8 frequency became crowded. There was much less congestion on FT4, and the run rate was better, so I found that to be effective. I enjoyed the SSB pileups for a while but found it to be a challenge to manage them. While I can work CW, I did not try to manage a pileup on that mode.

I found a 2m repeater on the island 146.73 MHz (—offset, no tone) and made a few calls on it, but I did not receive a reply.

QSLs will be via Logbook of The World only. I won’t be printing cards for this effort but the logs for VP2V/K0NR and VP2V/K0JJW are already loaded into LoTW. Thanks to everyone that worked us!

British Virgin Islands

BVI was a fantastic place to vacation. During our ten days there, we enjoyed the beaches, snorkeling, and sailing excursions. If you are interested in that, there are many online tourism sites to explore.

Bob/K0NR and Joyce/K0JJW are walking one of the many beautiful beaches in BVI.

Thanks for stopping by.

73 Bob VP2V/K0NR

The post VP2V/K0NR: Another Slacker DXpedition appeared first on The KØNR Radio Site.

Manna80 and other Special Event Stations

 You may wish to add these to your calendar

We will publish a report in The Communicator's next issue.

I would like to inform you about a few special event stations we will put up in the next few months. 

February 14,15 and 16th, PA80OV will be operational from Gennep, Netherlands. 
I will be a guest operator, and probably the organisation has written to you allready, but it is nice to know. 

https://radioclublimburg.nl/pa80ov/

~ Sander

----------------------------

The two others are also very interesting. 

At the end of WW2, the Netherlands suffered a hunger winter. Allied forces conducted a humanitarian action called Operation Manna. 
In April this year, 80 years ago, tons of food was dropped over the western part of the Netherlands, saving many people from starvation and death. 


To commemorate this event, we will activate a couple of stations, including GB80MAN, VE80MAN, VK80MAN, PH80MAN. 
We are hoping Poland is participating as well, and we hope the USA will put up a station. 

https://manna80.radio/the-team-in-the-netherlands/

As you have seen some SES from us, we will put up PH80MAN at a former drop zone. 
I have added a flyer with this mail.  This one is in Dutch, but an English version is under construction... will follow as soon as it is done!

Lastly, I would like to inform you about PA82AD. 
This is a call we used 5 years ago to celebrate 75 years of freedom. We held a DX-pedition but due to COVID, we could not really complete our goals. 
Please read the qrz.com page from bottom up. 

https://www.qrz.com/db/PA82AD

To finish this DX-pedition as planned, we will be operational for a very last time. 

Thanks again for reading, and hope to hear you on the bands. 

73, 

~ Sander PD9HIX


 


Hams meet Marines

A special event station from The Netherlands

 

 

This is an HF activity on January 23 from PA25MC, which will be on the air for just one day to introduce Marines to the world of ham radio. They will try to use as many HF-bands as possible on SSB. They remind us to please remember that Amateur procedures are new to them, but will do everything to get them up to speed quickly. 

Marines are used to speaking English but naturally keep their communications short. The organizers would really appreciate it if you contribute to a successful event by connecting with them!

PA25MC is organized and supported by PI4VBD, the club station of the Royal Army. Their station will always comply with the user regulations and regulations for radio amateurs and has no military function.

 
PI4VBD Royal Netherlands Army Signal Regiment on air 
 

QSL info for PZ5JT

Read carefully - send your card with return address, and without anything extra direct to:
PI4VBD / Verbindingsdienst,
Barchman Wuytierslaan 198, 
3818 LN Amersfoort, 
The Netherlands
 
~ Ton and Klaas-Jan
  John VE7TI
 

Erroneous Prepper Frequency Lists

Many “emergency frequency lists” showing up on the internet are a hodgepodge of frequencies scraped from various sources and assembled into what looks like a credible list. Some of these frequencies are useful, but too many are misleading and perhaps even dangerous. These lists gloss over training and licensing issues, as described here: The Talisman Radio.

Many of these lists are generated by copying other prepper lists or scanning various sources for “emergency frequencies.” Even this Wikipedia page about international distress frequencies includes some of this misinformation.

Important Disclaimer: People often point out that in many jurisdictions, a citizen without a radio license for a specific frequency can still make a call in case of a true emergency (usually defined as potential loss of life or property). This may be true, but it is generally not a good emergency communications strategy: See The Talisman Radio. Most of these lists do not address the issue of radio licensing at all, which is very misleading.

Here is a recent FCC action to consider: The FCC has ruled that a ham radio operator in Idaho must pay a record $34,000 penalty for interfering with wildfire communications on 151.145 MHz. This is a US Forest Service frequency not authorized for amateur radio licensees. So don’t be transmitting on unauthorized frequencies.

Misleading Frequency Lists

One of the worst frequency lists is shown here by Stryker Radios. This “Ham Radio Emergency Frequencies” list shows 29 frequencies, but only two are in the ham bands. The rest are a collection of airband, marine, FEMA, search and rescue, National Guard, US Air Force, etc. Most of these frequencies are not legal for the general public to use. An FCC amateur radio license permits operation on the two ham radio frequencies listed but nothing else. The 4Patriots has a similar list, leaving out the ham radio frequencies and calling the list “other emergency radio frequencies.” The Save Net Radio website also has a poorly thought-out frequency list. But they compound their errors with this statement:

It’s important to note that these frequencies aren’t just for professional rescuers and emergency workers; they can also be used by ordinary citizens who are equipped with the appropriate radio equipment.

This is incorrect and potentially dangerous.

Some Specific Frequencies

These emergency frequencies have three main uses: situational awareness (listening to learn what is happening in your environment), distress calls (calling out to anyone for help), and coordination with friends (communicating with friends and associates about supplies, health and welfare, transportation, weather, etc.)

We must consider our radio’s capabilities, specifically the frequency range (for transmit and receive, which may differ) and modulation type (AM, FM, SSB, etc.). The typical low-cost VHF/UHF radio that is so common (Baofeng UV-5R or similar) has a frequency range of 136 to 174 MHz (VHF) and 400 to 520 MHz (UHF). Many of these radios are shipped with their transmit frequency limited to the amateur (ham) radio bands: 144 to 148 MHz and 420 to 450 MHz. However, there may be a method to enable (or unlock) the entire frequency range for transmitting. Check the specifications of your radio model. These radios are almost always FM only, so no AM or SSB. Some radios can receive AM in the aircraft band but won’t transmit AM.

Listening to radio activity around you can be very helpful in understanding situational awareness. A good example is listening to your local fire or law enforcement channels. You can hear some of these frequencies using a low-cost VHF/UHF radio but a scanner that receives digital signals will be a lot more useful.

Let’s examine some of the frequencies in the Stryker list. I will skip the frequencies outside the typical VHF and UHF tuning ranges listed above, as your radio most likely won’t be able to tune them.

138.225 MHz: Primary FEMA channel for disaster relief operations.
This frequency is in the federal VHF band, but I could not confirm a specific usage.
To transmit on this frequency, you need federal authorization.

146.52 MHz: Ham radio frequency for non-repeater communications on the two-meter band.
This is the 2m FM calling frequency, which is generally lightly used. You may hear interesting traffic on this frequency but need a ham radio license to transmit on it.

151.625 MHz: Utilized by mobile businesses such as circuses, exhibitions, trade shows, and sports teams. Other channels in use are 154.57 and 154.60 MHz.
This is an itinerant business band frequency known as the Red Dot channel. The other two frequencies listed are MURS Channels 4 and 5. They may be useful to program in.

154.28 MHz: Local fire department emergency communication channel. Additional frequencies include 154.265 and 154.295 MHz.
These are Fire Mutual Aid channels (VFIRE21, VFIRE22, VFIRE23) set aside for when multiple fire districts need to communicate. Typically, each district has their own radio frequencies and only uses these when a large incident occurs with multiple agencies responding. An FCC license for these specific frequencies is required to transmit on them.

155.160 MHz: Local and state agency channel for search and rescue operations.
This is the most common VHF frequency for Search and Rescue. To transmit on it, you need an FCC license for this specific frequency.

155.475 MHz: Local and state police emergency communication channel.
This is a Law Enforcement Mutual Aid channel (VLAW31) set aside for when multiple law enforcement agencies need to communicate. An FCC license for this frequency is required to transmit on it.

156.75 MHz: International maritime weather alerts channel.
This is marine channel 15, receive only, reserved for listening to emergency locator beacons. This is not a normal communication channel and is probably not useful in an emergency.

156.80 MHz: International maritime distress, calling, and safety channel.
This is marine channel 16, the calling and distress channel, which may be useful in coastal areas, lakes, and waterways that have significant marine radio activity. This frequency is for marine / boating use using a certified VHF marine transceiver.

162.40 MHz to 162.55 MHz: Series of channels used for NOAA weather broadcasts and bulletins. Also 163.275 MHz.
These well-known weather broadcast stations cover a large portion of the US and are very useful to have programmed in your radio. Do not transmit on these frequencies.

163.4875 MHz: Nationwide emergency channel for the National Guard.
163.5125 MHz: National disaster preparedness frequency for the armed forces.
164.50 MHz: National communication channel for the Department of Housing and Urban Development.
These are federal frequencies requiring federal authorization to transmit on them.

168.55 MHz: Federal civilian agency channel for emergencies and disasters.
This frequency is assigned exclusively to smoke jumpers working on wildfire suppression.
Do not transmit on this frequency.

409.20 MHz: National communication channel for the Interstate Commerce Commission.
409.625 MHz: National communication channel for the Department of State.
These are federal frequencies requiring federal authorization to transmit on them.

462.675 MHz: General Mobile Radio Service channel for emergency communication and traveler assistance.
This is Channel 20 on GMRS and FRS radios. This frequency is probably useful, but it is subject to the GMRS and FRS rules.

Some of these frequencies may be useful to monitor in an emergency (situational awareness), but very few are available for distress calling or communicating with friends.

RadioMaster Reports Frequency List

This list originated on the Radiomaster Reports website and has spread around the web in various forms (see below). It is one of the better prepper frequency lists, but it still has some issues.

The FRS and GMRS frequencies are useful to have available. The PMR UHF frequency (446.03125 MHz) listed is actually in the 70 cm ham band in the US and is a non-standard frequency, so it should not be used at all in the US. (PMR is a European standard.) The CB frequencies listed are not available on your typical low-cost VHF/UHF handheld but are useful if you have a CB radio. The so-called CB Freeband frequencies are never legal for use and your standard CB won’t tune them.

The low-band VHF frequency of 33.4 MHz will also not work with your typical handheld radio. The FCC license database shows many businesses are licensed to operate on this frequency, including many fast food restaurants. I suppose if you want to order a hamburger in an emergency, it might work.

If you have the appropriate amateur radio license, the Ham VHF and HF frequencies listed are usable in the US. On the 2-meter band, 146.52 MHz is indeed the nationwide calling frequency and was discussed earlier. However, the frequencies of 146.42 and 146.55 MHz do not always conform to local band plans, depending on the area of the country you are in. So you may or may not find activity there. The Search and Rescue frequency (155.16 MHz) was discussed earlier. The two marine frequencies listed do not require a license but should only be used for boating and similar communications.

Summary

We could continue to examine the specifics of all these frequencies and discuss their equipment requirements, licensing requirements, and proper usage. However, the main message is that these frequency lists are just a collection of random stuff compiled and propagated around the web.  None of them are well-considered and most will likely not do you much good in an emergency.  And they might lead uninformed citizens into using a frequency that can get them into a heap of trouble.

I have been looking for a list to recommend but have not found one. Let me know if you come across one that is truly useful.

That’s what I found. Let me know what you think.

73 Bob K0NR

References

National Field Operations Guide (NFOG)
https://www.cisa.gov/safecom/field-operations-guides

NTIA Redbook
https://www.ntia.doc.gov/publications/redbook-manual

RadioMaster Reports Frequency List
https://radiofreeq.wordpress.com/wp-content/uploads/2013/06/shtf_survivalist_radio_frequency_list.pdf

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Which Modes Have You Operated?

Graphic courtesy of Ham Radio School

For our local 2m net, the Net Control Station asks a Question of the Night to stimulate some discussion. Recently, the question was:

Do you have any interest in CW. If yes, Do you currently operate CW or do you plan to learn? If you have no interest in CW, what other modes besides voice do you operate on or would like to?

I am not a huge CW fan, but I do use it from time to time, especially when it comes to squeezing out difficult contacts on VHF or UHF. However, this question had me thinking about the various modes I have operated, so I made a list:

SSB - quite often on HF, VHF, UHF
CW  - not nearly as often but on HF, VHF, UHF
FM/PM - lots of VHF activity here, 2m FM is the Utility Mode
AM  - a few times, just to check it out
RTTY - I used to do this often but my interest has faded
PSK31 - I used to do this often but my interest has faded
FT8 - this one has taken over my digital operating
FT4 - a faster alternative to FT8, often better to use
Q65 - I just started using this for weak-signal VHF/UHF
MSK144 - for meteor scatter, but I haven't done that for a while
AX.25 - VHF packet radio, including APRS
DMR - the most common digital mode in Colorado
D-STAR - I used D-STAR when it first came out but lost interest
C4FM - Yaesu Fusion, I've used it a few times

Each one of these modes has a story behind it…often I was just looking for something new to try. (If you find yourself getting bored with ham radio, it might be time to try a new mode.)

This list also reminds me that I need to get back to chasing grids on the 2-meter band, using CW, SSB, FT8, MSK144, and Q65. I have a new tower up that I’ve not taken full advantage of for VHF/UHF.

That’s my list of modes used, what does your list look like?

73 Bob K0NR

The post Which Modes Have You Operated? appeared first on The KØNR Radio Site.


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