Choosing Simplex Frequencies in 2m and 70cm bands

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kayn1n32008

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You are making this so much more difficult than it needs to be.

Pick an initial 'call' channel. Once established, go to one of your designated simplex channels.

In my VHF radios, I have 2 banks of channels. One for the 146.xxxMHz simplex channel and one bank of the 147.xxxMHz simplex channels. Channel 1 in each bank is 146.520MHz amd is labeled as VHF Call.

In my P25 radio I have an additional bank of P25 simplex channels. In my DMR portable I've got an additional bank of DMR simplex channels.

My province has coordinated an 'ARES' VHF simplex channel and a VHF portable repeater pair, on UHF we have 2 simplex channels and 2 portable repeater pairs coordinated.

Is it excessive? Yup.
 

sallen07

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Maybe I’m just a simple person, but if someone finds one side of your semi-duplex setup what stops them from finding the other side. Or am I missing something?
^This.

And if the conversation is *SO* "interesting" that I really really want to hear it, I won't be using a radio to try to do that, I'll be using a scanner, where I can quickly search the whole 2m band for traffic and lock onto anything I want to hear.

Oh, but you say, that will still be only one half of the conversation! True ... but I have more than one scanner. :)

That also ignores the fact that one can usually get a pretty good understanding of a two-way conversation by listening to one side. Go stand next to someone on the phone and you will see that.
 

CoastalDude

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A couple of things to keep in mind:

Your 145.300 is in the repeater sub-band, so you could be on repeater input frequencies. Just make sure there are no repeaters in your area using that as an input frequency.

You'll also need to figure out how to add more radios to this setup, unless you are going to scan. That means additional channels that may be congested and prevent communications. Remember, you are supposed to monitor before transmitting to make sure the channel is free.

Where can I get a breakdown of the "assigned ranges" within the 2m and 70cm bands? It seems surprisingly small now that I'm really getting into it? I was doing some testing on my little duplex setup from one end of the house to the other. I started picking up traffic I think from a repeater, but interestingly it was bleeding out through a huge range of frequencies? I thought a 0.050 pop was enough to separate signals but this stuff was coming across a very wide range?

Anyway, is there a list of these ranges, been searching, cannot find a really clear break down. I think I'm going to get the next level up from Technician as I need more bandwidth and just simply love this stuff ...
 

CoastalDude

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Maybe I’m just a simple person, but if someone finds one side of your semi-duplex setup what stops them from finding the other side. Or am I missing something?

No, you're right, they could probably find it via Scanning, probably a silly venture, a little less excited about it now, but I did get it working last night and learned a lot ...
 

CoastalDude

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Where can I get a breakdown of the "assigned ranges" within the 2m and 70cm bands? It seems surprisingly small now that I'm really getting into it? I was doing some testing on my little duplex setup from one end of the house to the other. I started picking up traffic I think from a repeater, but interestingly it was bleeding out through a huge range of frequencies? I thought a 0.050 pop was enough to separate signals but this stuff was coming across a very wide range?

Anyway, is there a list of these ranges, been searching, cannot find a really clear break down. I think I'm going to get the next level up from Technician as I need more bandwidth and just simply love this stuff ...


144.000-144.100CW (Continuous Wave, Morse Code)
144.100-144.275Single-sideband (SSB Calling Frequency = 144.200)
144.275-144.300Propagation Beacons
144.300-144.500OSCAR (satellite) APRS Frequency = 144.390 MHz
144.500-144.900FM Repeater Inputs
144.900-145.100Packet Radio
145.100-145.500FM Repeater Outputs
145.500-145.800Misc. and experimental modes
145.800-146.000OSCAR (satellite)
146.010-146.385FM Repeater Inputs
146.400-146.595FM Simplex (National Simplex Frequency =146.52 MHz)
146.610-147.390FM Repeater Outputs
147.405-147.585FM Simplex
147.600-147.990FM Repeater Inputs

I found this ...
https://www.hamradioschool.com/post/what-frequency-do-i-use-on-2-meters


Am I just a newbie or is that Simplex range incredibly narrow?
 

mmckenna

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Where can I get a breakdown of the "assigned ranges" within the 2m and 70cm bands? It seems surprisingly small now that I'm really getting into it? I was doing some testing on my little duplex setup from one end of the house to the other. I started picking up traffic I think from a repeater, but interestingly it was bleeding out through a huge range of frequencies? I thought a 0.050 pop was enough to separate signals but this stuff was coming across a very wide range?

Would need to know more about what you were hearing. You should have plenty of separation frequency wise, however some low end radios may not handle that very well with little physical separation between radios. Or, it's other users. I've found that some hams are running gateways on simplex frequencies that allow them to link into the internet nodes. They are simplex and use the same band plan. I've found some locally that choose to ignore the "gentlemen's frequency step agreement" and will start yelling at you that "U R off freQuenZiEES!!!" quite loudly.

I think I'm going to get the next level up from Technician as I need more bandwidth and just simply love this stuff ...

Moving from a Tech to a General or Extra won't give you any more frequencies on 6 meters or above. You still will have the same access to the same bands you do now, and the band plans still apply.

Am I just a newbie or is that Simplex range incredibly narrow?

No. Remember, you can use any frequency in that range. The general suggestion is you use what ever frequency step is suggested in your area. Some parts of the country use 15KHz steps, so:
146.400
146.415
146.430
146.445
146.460
146.475
146.490
146.505
146.520 -National Simplex Calling
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

Some parts of the country may suggest 20KHz or 30KHz steps. But remember, 2 meter band is NOT channelized and you can technically use any frequency in that range, you just may run into issues with other users that you will need to cooperate with and resolve. <—Part of being a "good" ham is learning to work with other hams, even if you disagree with them.


70cm band gives you 445-447MHz for simplex use, but shared with repeaters.

While harder to get portable radios for:
33cm (900MHz) band will give you a little space around 927MHz that's less likely to have other users. Many are using retired commercial equipment on this band, so it's not something you easily purchase on line.

222-225MHz is also an option. A bit easier to get 1.25 meter band amateur radios, often less users.

Ham radio is not the place if you want secure communications. Encryption is not allowed for these sorts of uses, and anyone can listen in. False sense of security in your comms is a bad thing. This isn't the right place for it. Make it easy on yourself and just run simplex, less chances of you causing interference that way, and much easier to coordinate.
 

nd5y

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Where can I get a breakdown of the "assigned ranges" within the 2m and 70cm bands?
Your state or regional frequency coordinator may have additional band plans that are different than the national/ARRL ones.

The main areas to avoid in the US are:
FM is not allowed in the CW-only subband on 2 meters 144.0-144.1
Don't use the satellite subbands 145.8-146.0, 435.0-438.0
Don't use FM in the weak signal areas 144.0-144.4, 222.0-222.25, 431.0-433.0
 

rescuecomm

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As noted, hiding in plain sight is much easier on 222 mhz. There are a number of multi band handhelds available along with single band mobiles. You can get an HT and a mobile for less than $200.00. Not public safety standards but good enough to get started.

There are three 222 mhz repeaters around here and barely a peep on them.
 

W0BTU

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I think I'm going to get the next level up from Technician as I need more bandwidth and just simply love this stuff ...
If you have a Technician class amateur radio license, you must have had it for a loooong time. I'm 99% sure that all new wannabe hams have just two choices, General and Extra. No?

Before CW was a requirement, the Technician and General exams were identical.
 

mmckenna

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If you have a Technician class amateur radio license, you must have had it for a loooong time. I'm 99% sure that all new wannabe hams have just two choices, General and Extra. No?

Before CW was a requirement, the Technician and General exams were identical.

No, you are thinking about the old Novice class. That's gone.
Technician is the entry license. General, then Extra.
 

CoastalDude

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A couple of things to keep in mind:

Your 145.300 is in the repeater sub-band, so you could be on repeater input frequencies. Just make sure there are no repeaters in your area using that as an input frequency.

You'll also need to figure out how to add more radios to this setup, unless you are going to scan. That means additional channels that may be congested and prevent communications. Remember, you are supposed to monitor before transmitting to make sure the channel is free.

Thank you, I am redoing my frequency selections now, I'll stay within the designated Simplex frequency range. It seems very narrow, if indeed there ever was a national emergency I'd say you'd never be able to get out on such a narrow range as it would be absolutely overwhelmed with traffic
 

nd5y

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if indeed there ever was a national emergency I'd say you'd never be able to get out on such a narrow range as it would be absolutely overwhelmed with traffic
What is your idea of a national emergency, what do you think ham radio would be good for and what type of traffic do you think is going to overwhelm all of the VHF/UHF simplex channels?
 

mmckenna

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if indeed there ever was a national emergency I'd say you'd never be able to get out on such a narrow range as it would be absolutely overwhelmed with traffic

I think you may be over estimating the amount of traffic you'd hear in such a situation. After being a ham during many major disasters, the ham traffic tends to drop off as people worry about their own. What ham traffic there is tends to gather on a few frequencies (mostly repeaters).
 

Token

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No, you're right, they could probably find it via Scanning, probably a silly venture, a little less excited about it now, but I did get it working last night and learned a lot ...

No "scanning" required, at least not in the traditional sense of a scanning radio slowly stepping across the band. With something like an SDR it is possible to watch the entire 2m or 70cm bands (or both) and instantly see the activity.

Here is an example. Sure, this is not an example in a ham band, it is instead watching every frequency, simultaneously, from 451.5 to 463.5 MHz. But it could just as easily be a ham band ;) Once a signal is seen on the waterfall you just click on it to tune to the frequency and hear the traffic. Some software even allows "DVR" like operation, you click on the signal and play back past transmissions you were not tuned to at the time the transmission was made.
141428064.CnSgu3SI.450MHz_02102012.jpg


T!
 
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