P25 Simplex Frequency

[Jeff Lehmann N1ZZN]

As we seemed to be bugging some folks that didn't have PL on RX on 927.500, I think we should come up with a separate simplex frequency to use P25 on. Any suggestions? 927.600?

 

73

Jeff  N1ZZN

[Dave Newman]

Perhaps 927.2500

 

Dave WB1EVP

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[Lee M. Lemoine]

927.52750

Sincerely,
Lee M. Lemoine
N3LEE - Amateur Radio / WQGP447 - GMRS
"Experience is something you don't get until just after you need it."

[n1...@comcast.net]

This is the first time that I am hearing concerns about P25 simplex use on the main recognized simplex frequency. My initial reaction is two-fold:

1.  No licensed amateur has a higher right to a specific frequency than any other.

2.  I specifically set my receive up for mixed-mode receive and carrier squelch receive on analog to ensure that I would not inadvertently key up on top of an analog user. I would expect that good amateur practice would dictate that an analog user would also want to monitor the frequency for other users as well, either by simply listening in the clear or using a PL, but hitting "monitor" before actually trying to transmit.

One of the problems that I see with P25 users going off to another frequency on their own is that we further fracture the 900 community. At least with a common simplex frequency and my ability to monitor analog and digital concurrently, I can respond to friends either way. Moving P25 users to another frequency is probably the worst method for solving this minor problem. There are other elegant and intelligent solutions that do not require further splitting 900 users.

927.6000 is probably NOT a good selection for a designated simplex frequency since that is a NESMC recognized repeater output frequency. If the P25 users are to split from the analog users, a frequency at or below 927.4000 should be selected, excluding the four special repeater frequencies noted in the bandplan.

John

N1OTY

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From: "Jeff Lehmann N1ZZN" <n1...@comcast.net>
To: near...@googlegroups.com
Sent: Friday, February 22, 2013 12:23:41 PM

Subject: [Near-900] P25 Simplex Frequency

As we seemed to be bugging some folks that didn't have PL on RX on 927.500, I think we should come up with a separate simplex frequency to use P25 on. Any suggestions? 927.600?

 

73

Jeff  N1ZZN

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[Jeff Lehmann N1ZZN]

Sounds like 927.400 is the better option if we move. But as you said, maybe the better thing to do is make sure everyone on 927.500 analog is set up for 100.0 PL both RX & TX. All my radios are set up this way, mostly because that is a very popular baby monitor frequency.

The rumblings that I heard were people annoyed by hearing the P25 sound blasting out of their analog CSQ radios on 927.5. Any thoughts from the non P25 users, possibly not wanting to use PL?

73

Jeff  N1ZZN

[John Miller]

I use tone squelch anytime and every time I can anywhere and everywhere I can when on FM so if everyone wants to agree on a tone, it's no big deal to set my radios up with it.

[Lee M. Lemoine]

The option to program a sticky monitor button has always been in my codeplugs...   if your going to be in an area where there is mixed use; hit it...

Secondary to that; if you program your P25 channels to decode PL 100 (which i think everyone is using) you'll know there is analog traffic with a P25 rig.

Sincerely,
Lee M. Lemoine
N3LEE - Amateur Radio / WQGP447 - GMRS
"Experience is something you don't get until just after you need it."

[Richard J. Cabral, W1RJC]

I agree with N1OTY and N1ZZN about using 927.4000 is our unofficial-official P25 simplex frequency.  When I was at 900 night in Plymouth this past January, I looked at the NESMC bandplan and suggested that night that we decide on a separate frequency.  I mentioned to N1OTY and KC1HO that 927.4000 looked like a good suggestion, but no one came to a consensus then.  In any case, I am going to program in '4000 on my HT for P25.  I'd like to try this up at NEAR-Fest as well and hope others decide to join me on that frequency! :)

I program my radios and the ones I do for others with a monitor key as well.  I think it's a good idea before using either '4000 or '5000 to put the rig into monitor first just to be safe before making a call (just a good amateur practice).  I hear what others are saying about using P25 on '5000 still as a calling frequency and then moving off.  I also note how having two frequencies further separates the 900 community, however I think putting both modes on two different frequencies just makes better sense.  If you wish to monitor both for activity, you could always do a custom scan group that scans the two frequencies.  That is just my opinion and preference, however.

[n1...@comcast.net]

This almost reminds me of some repeater owners back twenty years ago who fought against putting PL on their inputs as a defense against users of other machines bleeding onto their repeater, instead insisting that they were somehow entitled to a massive exclusion zone. How dare someone put up a repeater 75 miles away on THEIR frequency!!!

Maybe this minor blow up is indicative of the 900 band coming-of-age and that it is becoming more main stream. I suppose there is good and bad in that. Interestingly, I have not found any instances of the VHF folks at 2-meters demanding that the P25, DMR or NXDN simplex users go off on their own, but that may be because .52 is a "calling" frequency only, whether analog or digital, so the signals on that frequency are brief. I've been hesitant, very reluctant, to call for 927.5000 to be transformed into a calling frequency only, but I may have to propose this at the next NESMC meeting.

John

N1OTY

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From: "Jeff Lehmann N1ZZN" <n1...@comcast.net>
To: near...@googlegroups.com

Sent: Friday, February 22, 2013 5:22:23 PM

Subject: Re: [Near-900] P25 Simplex Frequency

[n1...@comcast.net]

I have been reluctant to call for 927.5000 to be relabeled as a "calling frequency" under the NESMC band plan, but I feel it may be time to do so. I note that the Connecticut coordinating body does just that as indicated here:

http://www.ctspectrum.com/home/bandplan/902mhz

My reluctance to make .5000 a calling channel is due to the fact that there are still many users of Motorola GTX radio's, both the four and ten channel variety, and the 16 channel MTX's. Those users are already faced with hard choices concerning what gets programmed into their code plug and what gets left out. Adding a couple of additional simplex frequencies means leaving out additional repeaters. If the analog and digital users work cooperatively on 927.5000, we won't have to throw the GTX and MTX users under the bus.

John

N1OTY

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From: "Richard J. Cabral, W1RJC" <goo...@rjcabral.com>
To: near...@googlegroups.com
Sent: Friday, February 22, 2013 10:28:55 PM

Subject: Re: [Near-900] P25 Simplex Frequency

I agree with N1OTY and N1ZZN about using 927.4000 is our unofficial-official P25 simplex frequency.  When I was at 900 night in Plymouth this past January, I looked at the NESMC bandplan and suggested that night that we decide on a separate frequency.  I mentioned to N1OTY and KC1HO that 927.4000 looked like a good suggestion, but no one came to a consensus then.  In any case, I am going to program in '4000 on my HT for P25.  I'd like to try this up at NEAR-Fest as well and hope others decide to join me on that frequency! :)

I program my radios and the ones I do for others with a monitor key as well.  I think it's a good idea before using either '4000 or '5000 to put the rig into monitor first just to be safe before making a call (just a good amateur practice).  I hear what others are saying about using P25 on '5000 still as a calling frequency and then moving off.  I also note how having two frequencies further separates the 900 community, however I think putting both modes on two different frequencies just makes better sense.  If you wish to monitor both for activity, you could always do a custom scan group that scans the two frequencies.  That is just my opinion and preference, however.

[John Miller]

I'd like to see 927.5 as a calling frequency personally. I like that idea.

John N1UMJ

[Lee M. Lemoine]

This is exactly what I just wrote about in my other thread.... 

The frequency exclusions are unrealistic; nobody is entitled to -140dbm exclusion zones (unless your Pave Paws, of course)

I've been running mixed mode DMR/Analog on 146.625 in Cumberland for 9 months.  I received exactly TWO emails about it -- one asking how to "make it go away when it's digital" (enabling receive PL) and another about which color code it was running.   That's it.  

The bandspread on amateur is exclusive in many ways; but -- we're lucky to have fixed 600khz spreads.   So lucky, in fact, that if the FCC does start going after bandwidth if this "T-band" takeback fails, that it would not surprise me to see public safety end up there, specifically for the fixed repeater splits.   See; this was what was supposed to happen from 166-174mhz when TV stopped broadcasting analog; but the TV stations applied for a VHF waiver; throwing a wrench in the gears on that....   Needless to say, the VHF T-band didn't hapen; and we've still got a hodge-podge of inputs and outputs.

That being said; we've got a -45dbm contour in commercial.  90% of our licenses now granted are at 25W ERP and for a 8kilometer (~5mile) radius.  The 100w days of the past are gone, and i can't wait until they start forcing incursion zones as they do in other countries.   You design a system, submit the contour, and have to follow your design contour within 3db.   No more; no less...   This has lead to the proliferation of FM simulcast technologies, or other linear technologies that lend better to zero-power carrier applications such as TETRA.

So why the lag?  Why are we doing all this stuff commercially and now the AMATEURS lag the COMMERCIAL WORLD.   Isn't it supposed to be the other way around?   Why exactly do we have all this bandwidth if we're not responsible enough to lead-by-example, and show everyone else how to be more efficient?


927.5000 calling?  927.520 as calling?   Why prohiibt digital users from using the calling frequency, providing that NESMC specifies a new england carrier squelch tone.   This can be decoded by both analog and digital units.  (See other thread)

Sincerely,
Lee M. Lemoine
N3LEE - Amateur Radio / WQGP447 - GMRS
"Experience is something you don't get until just after you need it."

[Jason Janvrin]

I dispute the notion that 146.520 is a "calling frequency".  It is the "national simplex frequency".  Note calling does not appear in that title? 

Before I go into ultra conservative mode among progressives, I bid you 73 (not 73's.  How silly to say best regards's)

WA1NH

Sent from my rooted Android device.

[Steven Donnell]

Just curious if anyone besides myself still listens on 146.520? Various
digital modes (possibly) interfering w/ analog users on VHF/UHF freqs
are one thing, but given the amount of users and propagation on 900, Id
say its a non-issue. Someone on 900 in most places isnt going to be
heard on simplex even 5 mi away. Ive tried calling CQ on 927.500 from
various hilltops and have never gotten a reply.

If someone does has an issue w/ digital on 927.500, or elsewhere, then
pick another freq. You could also do simplex on a repeater output. Thats
progressive enough isnt it? 146.34/.94 and 146.94/.94. These days thats
called Talk Around :)

Steve WA1YKL

[n1...@comcast.net]

I might disagree with you on your position based on this:

http://www.nesmc.org/docs/bandplans.pdf

It is plainly referred to as a national simplex calling frequency.

John

N1OTY

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From: "Jason Janvrin" <ike...@gmail.com>
To: near...@googlegroups.com
Sent: Saturday, February 23, 2013 1:44:09 PM

Subject: Re: [Near-900] P25 Simplex Frequency

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[n1...@comcast.net]

I am seriously contemplating proposing this very thing at the next NESMC meeting.

John

N1OTY

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From: "John Miller" <n1um...@gmail.com>
To: near...@googlegroups.com
Sent: Saturday, February 23, 2013 8:39:30 AM

[Richard Solomon]

The ARRL Bandplan says the same thing, so it must be true !!

73, Dick, W1KSZ

[Bill Smith]

Two questions.

 

1)      What “early portables” required monitor before transmit? I’ve been working on LMR since 1971 and I don’t recall any. If you are talking mobiles, then yes there are plenty.

2)      What is this about 166-174 MHz? That was never on the block. It’s mostly federal spectrum. Perhaps  you meant 174-216 MHz which is fantastic LMR spectrum. And not a bad place for PS to go to if they do get kicked off T-band.

 

Bill

 

 

From: near...@googlegroups.com [mailto:near...@googlegroups.com] On Behalf Of Lee M. Lemoine
Sent: Saturday, February 23, 2013 10:13 AM
To: near...@googlegroups.com
Subject: Re: [Near-900] P25 Simplex Frequency

 

This is exactly what I just wrote about in my other thread.... 

[Lee M. Lemoine]

I believe they were most prominent on the portable "lunchbox" units...  i've only gotten the chance to play with one that was operational once -- but, it had the complete manual with it.   In the notes, and labeled on the small palm mic were labels which indicated the radio needed to have the monitor switch depressed or the mic lifted off of the receiver to enable transmit.  

The spectrum that was supposed to be re-allocated was to be located within the existing confines of most commercial equipment.  This would lead me to suggest 174 back 6 mhz, to roughly 168 -- a standard analog TV freq)  but that all happened back in ~2008 when I first got involved with NPSTC.   But; after looking again, the frequencies did start at 175; so....  back to doing digging!

After doing some more digging; it was supposed to be Analog Ch 7-13; 174-219mhz roughly.  

The thought was to have some 3 and 5 mhz split arranged around fixed 10mhz TETRA.  

I'd really like to see demilitarization of the 350-380 band; and see TETRA deployed there.   Since TETRA has a standard 10mhz spread; it doesn't line up well with the existing structure in place for 5mhz spacing. 

Since the higher frequencies are desirable for cellular; i can't see the pressure really coming off the T-band occupants...  (470-512) of present; however, and equivalent gift in the VHF side would be welcome!

Sincerely,
Lee M. Lemoine
N3LEE - Amateur Radio / WQGP447 - GMRS
"Experience is something you don't get until just after you need it."