Simplex Channel Confusion on 2 Meters

I often get asked questions about the band plan for 2 meters (144 to 148 MHz). Usually, this is about choosing a suitable simplex frequency, because the repeater frequencies are already coordinated and visible.

I’ve written about 2m band plans before. This article attempts to cover the topic in a way that applies to all of the US. This is actually a challenge because VHF/UHF band plans are regional in nature.

What Frequency Do I Use On 2 Meters?

I also wrote this article which is specific to the state of Colorado.

It is always best to check your local VHF band plan, usually supplied by the frequency coordinating body for your area. Typically, their main focus is coordinating repeaters but simplex frequencies are also listed.  Most frequency coordinating bodies kind of follow the ARRL 2m band plan, while adapting it for local use.

Channel Spacing: 15 kHz or 20 kHz

A big issue for the 2-meter band is that some areas have adopted a 15-kHz channel spacing while others use a 20-kHz channel spacing.  A typical FM signal is about 16 kHz wide, so the 15 kHz channel spacing is a bit tight but does allow for more channels (resulting in more adjacent channel interference issues). The 20-kHz spacing is “cleaner” but with fewer channels.

This map from the ARRL web site shows the channel spacing in use across the various states.

Map of the US showing 15 kHz and 20 kHz channels on the 2-meter band.

The channel spacing is driven by factors associated with repeater coordination, and simplex usage tends to adopt the same spacing. (There is no technical reason that simplex has to use the same channel spacing as the repeaters but that’s what usually happens.)

Some repeater coordinating organizations have done a good job of prescribing FM simplex frequencies. The Colorado 2m band plan (called the Frequency Use Plan) lists each simplex frequency individually.  The Illinois Repeater Association uses a similar approach: Illinois 2m Band Plan. The Southeastern Repeater Association (SERA) 2m band plan is also very specific. Note that the SERA band plan indicates that some of the usual 2m simplex frequencies may be used as repeater pairs — an example of a local decision on frequency use.

The Arizona 2m band plan shows a range of frequencies to be used for FM simplex, such as 146.400 – 146.600 MHz along with a note that says the Even 20 kHz Frequencies should be used. So that means the preferred simplex frequencies in this range are 146.40, 146.42, 146.44, 146.46, 146.48, 146.50, 146.52, 146.54, 146.56, 146.58 and 146.60 MHz. Some repeater coordinating bodies just give the frequency segment allocated to FM simplex and don’t mention the channel spacing. And some organizations don’t say anything about FM simplex so you have to figure them out on your own.

Recommendations

So what do we make of all of this? When it comes to 2m FM simplex frequencies, try to find your local band plan. If it recommends 2m FM simplex frequencies, then follow that guidance.

If that doesn’t work, look at the map above to determine if your state uses 15 kHz or 20 kHz spacing. Then follow the guidance in the HamRadioSchool.com article: What Frequency Do I Use on 2 Meters?

2M FM Simplex Frequencies (typical usage, check your local band plan)
15 kHz Channels 146.400, 146.415, 146.430, 146.445, 146.460, 146.475, 146.490, 146.505,146.520, 146.535, 146.550, 146.565, 146.580, 146.595 147.405, 147.420, 147.435, 147.450, 147.465, 147.480, 147.495,147.510, 147.525, 147.540, 147.555, 147.570, 147.585
20 kHz Channels 146.400, 146.420, 146.440, 146.460, 146.480, 146.500, 146.520, 146.540, 146.560, 146.580, 146.600 147.400, 147.420, 147.440, 147.460, 147.480, 147.500, 147.520, 147.540, 147.560, 147.580

In all cases, remember that these are shared frequencies so you need to cooperate with other radio hams. If you bump into existing activity, go ahead and try another frequency. There are usually plenty of quiet simplex channels around.

The one simplex frequency that everyone does seem to agree on is the National Simplex Calling Frequency: 146.52 MHz. For some thoughts on how to use that frequency see: The Use of 146.52 MHz.

I do think that frequency coordination bodies would be wise to provide guidance on simplex channels. This is not frequency coordination but it helps the amateur radio community be more effective in using the spectrum.

73 Bob K0NR

The post Simplex Channel Confusion on 2 Meters appeared first on The KØNR Radio Site.


Bob Witte, KØNR, is a regular contributor to AmateurRadio.com and writes from Colorado, USA. Contact him at [email protected].

13 Colonies wallpaper arrived today.

The wallpaper arrived today for my participation in the 13 Colonies Special Event from July1-7th. This was a great event and my first time taking part in it, I am looking forward to next years event.



Mike Weir, VE9KK, is a regular contributor to AmateurRadio.com and writes from New Brunswick, Canada. Contact him at [email protected].

McQuaid Butte SOTA

McQuaid Butte (W0C/SP-019) is a 9043-foot mountain near our cabin in Park County. Joyce/K0JJW and I activated it for Summits On The Air (SOTA) way back in 2013 but for some reason, we had not been back to it. The access road (Salt Creek Road, FS 435) is gated closed from January 1 to June 15 to protect wildlife habitat, so I suppose that is a factor.

McQuaid Butte (W0C/SP-109) as viewed from the south.

Today, we decided to make a return trip to the summit and activate it on VHF/UHF. I remembered that Salt Creek Road can turn into a muddy mess but today it was dry and easily drivable with most vehicles. Salt Creek Road is accessed from Highway 285, south of Fairplay but north of Antero Junction.

Access to McQuaid Butte is via Salt Creek Road, from Highway 285.

There is a good parking spot shown on the map above at 38.95791, -106.00790. A trail begins here, heading east. It used to be 4WD road but it is now closed to motor vehicles. This trail/road heads east and then curves to the north and eventually disappears. About that time, you’ll encounter a fence that needs to be crossed as you make your way towards the summit (approaching from the west). There are pieces of a trail here and there but its mostly bushwacking up the side of the summit. In places, there is substantial downed timber that can be stepped over and around but its mildly annoying.

Bob/K0NR relaxing on the summit.

Our route turned out to be 1.3 miles one way with 650 vertical feet. We both quickly made enough QSOs to qualify for activator points, working W0BV, KD0MRC, K0MGL, WZ0N on 2m FM (and some on 70 cm). The weather was excellent, resulting in a fun SOTA activation in the Pike National Forest.

We will probably return again to this summit because it’s a nice hike that is easy to get to from our cabin.  It would also be a great choice for someone passing through on Highways 24 or 285.

73 Bob K0NR

The post McQuaid Butte SOTA appeared first on The KØNR Radio Site.


Bob Witte, KØNR, is a regular contributor to AmateurRadio.com and writes from Colorado, USA. Contact him at [email protected].

Weekly Propagation Summary – 2020 Aug 03 16:10 UTC

Weekly Propagation Summary (2020 Aug 03 16:10 UTC)

Here is this week’s space weather and geophysical report, issued 2020 Aug 03 0354 UTC.

Highlights of Solar and Geomagnetic Activity 27 July – 02 August 2020

Solar activity was very low throughout the period. Three spotted regions populated the disk at various times during the summary period. Region 2767 (S21, L=200, class/area Hsx/120 on 26 Jul) maintained an H-type configuration through the period and was quiet and stable. Region 2768 (N26, L=111, class/area Hsx/020 on 30 Jul) formed on the disk on 28 Jul and decayed to plage by 02 Aug. It was quiet and stable. Region 2769 (N26, L=059, class/area Axx/010 on 02 Aug) quietly rotated onto the disk.

An eruptive prominence was observed off the SE limb about midday on 31 Jul. A slow-moving CME was subsequently observed, but was determined to not have an Earth-directed component. No other CMEs or activity of note was observed during the summary period.

No proton events were observed at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit was at normal to moderate levels through the period.

Geomagnetic field activity was at quiet levels through midday on 02 Aug when unsettled activity was observed due to positive polarity CH HSS influence. Solar wind observations indicated nominal conditions through about 02/0600 UTC when a CIR, in advance of a positive polalarity CH HSS, became evident in the data. Wind speeds increased from about 310 km/s to near 530 km/s, total field increased to 12 nT and the Bz component reached -10 nT. The geomagnetic field reacted with mostly unsettled conditions.

Forecast of Solar and Geomagnetic Activity 03 August – 29 August 2020

Solar activity is expected to be at very low levels throughout the outlook period.

No proton events are expected at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit is expected to be at normal to moderate levels throughout the outlook period.

Geomagnetic field activity is expected to be at unsettled to active levels through 03 Aug with a chance for G1 (Minor) geomagnetic storm levels due to recurrent CH HSS effects. Quiet to unsettled levels are expected on 04 Aug as HSS effects persist. Unsettled levels are expected once again on 29 Aug. Quiet levels are expected to prevail for the remainder of the period, 05-28 Aug.

Don’t forget to visit our live space weather and radio propagation web site, at: http://SunSpotWatch.com/

Live Aurora mapping is at http://aurora.sunspotwatch.com/

If you are on Twitter, please follow these two users: 1. https://Twitter.com/NW7US 2. https://Twitter.com/hfradiospacewx

– – – – – – – – – – – – –

Be sure to subscribe to our space weather and propagation email group, on Groups.io

https://groups.io/g/propagation-and-space-weather

Spread the word!

– – – – – – – – – – – – –

Links of interest:

+ Amazon space weather books: http://g.nw7us.us/fbssw-aSWSC
+ https://Twitter.com/NW7US
+ https://Twitter.com/hfradiospacewx

Space Weather and Ham Radio YouTube Channel News:

I am working on launching a YouTube channel overhaul, that includes series of videos about space weather, radio signal propagation, and more.

Additionally, I am working on improving the educational efforts via the email, Facebook, YouTube, Tumblr, and other activities.

You can help!

Please consider becoming a Patron of these space weather and radio communications services, beginning with the YouTube channel:

https://www.patreon.com/NW7US

The YouTube channel:
https://YouTube.com/NW7US

..


Visit, subscribe: NW7US Radio Communications and Propagation YouTube Channel

ICQ Podcast Episode 330 – Organising a SOTA Weekend

In this episode, Martin M1MRB is joined by Chris Howard M0TCH, Martin Rothwell M0SGL, Ed Durrant DD5LP, Frank Howell K4FMH and Bill Barnes WC3B to discuss the latest Amateur / Ham Radio news. Colin M6BOY rounds up the news in brief and this episode’s feature is Organising a SOTA Weekend.

ICQ AMATEUR/HAM RADIO PODCAST DONORS

We would like to thank an anonymous donor along with our monthly and annual subscription donors for keeping the podcast advert free. To donate, please visit - http://www.icqpodcast.com/donate

- Australian Call Sign Structure - ARRL - What's wrong with ham radio? - Unauthorized Transmissions in 144 MHz Satellite Allocation - HobbyKing Fined Nearly $3 Million for Marketing Unauthorized Drone Transmitters - High school Marine Buoy Transmitter Now Active on 20m WSPR - QSO Today Virtual Ham Expo - SOTA Day 2020 (Austrian) - RASA’s QTC Magazine Moves to Fully Electronic


Colin Butler, M6BOY, is the host of the ICQ Podcast, a weekly radio show about Amateur Radio. Contact him at [email protected].

Ham College 67

Ham College episode 67 is now available for download.

Extra Class Exam Questions – Part 5
E1E Volunteer examiner program: definitions, qualifications, preparation and administration of exams, accreditation, question pools, documentation requirements.

57:40

Download
YouTube


George Thomas, W5JDX, is co-host of AmateurLogic.TV, an original amateur radio video program hosted by George Thomas (W5JDX), Tommy Martin (N5ZNO), Peter Berrett (VK3PB), and Emile Diodene (KE5QKR). Contact him at [email protected].

Tweaking the Endfed antenna SWR chart correction

 I was reading my most recent post and something clicked.....and it was not a good "click". I looked at the posted SWR chart from my 44-foot antenna experiment and the numbers looked very familiar! Somehow I copy and pasted the numbers from the 41 foot SWR results and reposted them for the 44-foot experiment. Below are the corrected results for the 44-foot Endfed wire. 

SWR with a counterpoise:

Band          Freq             SWR
80m            3.500            8.4
80m            4.000            9.0
40m            7.001            4.6
40m            7.060            4.6
30m           10.100           4.6
30m           10.150           4.6
20m           14.001           2.1
20m           14.060           2.1
17m           18.068           2.3
17m           18.168           2.3
15m           21.001           3.1
15m           21.060           3.1

SWR without a counterpoise:

Band          Freq             SWR
80m            3.500            6.8
80m            4.000            6.1
40m            7.001            3.5
40m            7.060            3.5
30m           10.100           4.6
30m           10.150           4.6
20m           14.001           1.4
20m           14.060           1.4
17m           18.068           2.0
17m           18.168           2.1
15m           21.001           3.1
15m           21.060           3.1

Mike Weir, VE9KK, is a regular contributor to AmateurRadio.com and writes from New Brunswick, Canada. Contact him at [email protected].

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