US VHF low land mobile band - still in use?

[dave-h]

I'm a scanner listener located in New Zealand and have a general question regarding the use of the VHF low band in the USA.
Back in the 90s during high sunspot activity it was possible to get solid copies of the emergency services operating throughout a large area of the southern and western United States on a daily basis. Many fire departments and police services were heard between 30 and 45 MHz and made pretty interesting listening.

With the solar activity starting to increase again, I was wondering if many of these frequencies are still being used, or have the majority of them migrated to higher frequencies now?

 

[ecps92]

There are still users of Low Band in the US

You may want to view the on-going thread

2021 VHF Low Band Logs

Here's to hoping that 2021 is a better year for VHF Low Band propagation than 2020 was! My first log of the new year (all of my radio logs are in UTC): 40.670 - SNOTEL with very strong signal -- San Antonio TX BCD996XT Scanner with 10 Meter Dipole

forums.radioreference.com

I'm a scanner listener located in New Zealand and have a general question regarding the use of the VHF low band in the USA.
Back in the 90s during high sunspot activity it was possible to get solid copies of the emergency services operating throughout a large area of the southern and western United States on a daily basis. Many fire departments and police services were heard between 30 and 45 MHz and made pretty interesting listening.

With the solar activity starting to increase again, I was wondering if many of these frequencies are still being used, or have the majority of them migrated to higher frequencies now?

 

[Thunderknight]

Use has definitely declined since the 90s. A lot of users have switched to trunked systems in the higher bands. BUT, there are still plenty of users...just not nearly as many as 20+ years ago.

 

[mmckenna]

California Highway Patrol is still using low band, and will be for the foreseeable future. No plans to change, in fact, they just bought a few thousand brand new low band mobile radios.

 

[GlobalNorth]

VHF low band in Arizona is nearing extinction level - small fire departments gave it up for VHF high or UHF, counties that used to have assigned frequencies have surrendered them, as well as the State.

As the big public safety and corporate users migrate to 700+ MHz and abandon VHF high and UHF, the smaller users are adopting VHF/UHF higher frequencies to avoid the elevated noise levels of low band.

 

[RFI-EMI-GUY]

Listen to these as they are licensed to be used anywhere in the US.

27.49 Base or Mobile 10.
35.04 Base or Mobile 10.
43.04 Base or mobile 17.

(10) This frequency will be assigned only to stations used in itinerant operations, except within 56 km (35 miles) of Detroit, Mich., where it may be assigned for either itinerant or permanent area operations (i.e., general use).

(17) This frequency will be assigned only to stations used in itinerant operations.

 

[Roodog2k]

With the solar activity starting to increase again, I was wondering if many of these frequencies are still being used, or have the majority of them migrated to higher frequencies now?

By me in the Northeast USA, I almost never hear anything on VHF-lo, unless they're using it as a backup when the VHF-hi or the UHF frequencies are occupied or their equipment is malfunctioning.

Although, I think my local volunteer ambulance is using the VHF-lo frequencies.

 

[WB9YBM]

I'm a scanner listener located in New Zealand and have a general question regarding the use of the VHF low band in the USA.
Back in the 90s during high sunspot activity it was possible to get solid copies of the emergency services operating throughout a large area of the southern and western United States on a daily basis. Many fire departments and police services were heard between 30 and 45 MHz and made pretty interesting listening.

With the solar activity starting to increase again, I was wondering if many of these frequencies are still being used, or have the majority of them migrated to higher frequencies now?

I've noticed a decrease in use on those frequencies the last few decades--it seems like every time there's an improvement in technology, users migrate to increasingly higher frequencies. Every so often (when I get bored with "regular" scanner monitoring) I'll do a band sweep of the lower frequencies (like the ones you mentioned) to see if anything shows up. So far I've not met with a lost of success--which surprises me (at least a little bit) since it doesn't seem to make a lot of sense to let frequencies go to waste. I've often wondered if someone will find a way to "recycle" those frequencies especially in highly populated areas where frequencies are at a premium. If nothing else, they could be used for things like a new CB band or ham radio use--it might not bring a lot of cash flow to the FCC as would commercial use but at least they'd get used...

 

[mmckenna]

If nothing else, they could be used for things like a new CB band or ham radio use--it might not bring a lot of cash flow to the FCC as would commercial use but at least they'd get used...

This has been brought up before, in various forms.

Hams have 6 meters, underused in most areas...

CB won't get that spectrum. Too many other users. Military has access to some of it, and they're not going to give it up. Last thing they want is having to deal with CB'ers.

It fell out of favor for a number of reasons:
Doesn't work well with hand held radios. The ground plane presented by the radio, even with a capacitively coupled user, is too small to be efficient.
The antennas for hand held use are even more inefficient. No one wants to walk around with a low band portable with a 5 foot long antenna.

Noise level is high on the band.

Large mobile antennas.

Skip can create lots of interference on the band when conditions are right. Suddenly a low band user in California is having a very clear conversation with a fire department on the east coast.

Kenwood is still actively making and selling low band radios, but there's only a handful of users. Luckily those users are large agencies that purchase enough radios to make it profitable. Most other radio manufacturers have given up on the band. Just not enough sales.

It does get used, though. I've always wanted to get an itinerant license and use it, but really don't need to. I've got other resources.

Luckily, the band isn't much use for anyone else other than LMR users. It wouldn't work well for cellular, so not much need for it.

 

[WB9YBM]

Hams have 6 meters, underused in most areas...

It fell out of favor for a number of reasons:
Doesn't work well with hand held radios. The ground plane presented by the radio, even with a capacitively coupled user, is too small to be efficient.

Large mobile antennas.

most ham VHF & UHF bands have gotten pretty quiet since cell 'phones have gotten so low in cost & prolific--as has e-mail.

Back when 30-40MHz was utilized by commercial interests was by taxicabs, ambulances, etc. and the majority of them seldomly if ever used H.T.s so I'm not sure if large antennas were much of an issue...

 

[mmckenna]

most ham VHF & UHF bands have gotten pretty quiet since cell 'phones have gotten so low in cost & prolific--as has e-mail.

Back when 30-40MHz was utilized by commercial interests was by taxicabs, ambulances, etc. and the majority of them seldomly if ever used H.T.s so I'm not sure if large antennas were much of an issue...

Right. It was a very popular band, and many large public safety agencies have retained their licenses. San Francisco PD, even though they use an 800MHz system, have retained their low band system for backup. In a jam, a couple of VHF low frequencies allows them to communicate pretty well in the hilly terrain. Last time I was up there, most of their vehicles still had an old Motorola MaxTrac low band VHF radio in them, and a Low band base loaded whip on the car. I don't know how often they use it, never had time to listen for any length of time.

Low band for portable, no so much. While they are out there, they don't work so well. Even California Highway Patrol, a heavy low band user, uses 700MHz hand held to talk back to the car, and link into the low band radios. Pretty reliable system that covers most (not all) of the state.

 

[WB9YBM]

many large public safety agencies have retained their licenses. San Francisco PD, even though they use an 800MHz system, have retained their low band system for backup.

There's a piece of the puzzle that had escaped me: I hadn't realized that there was still enough use of the lower frequencies (at least on paper) to make it worthwhile to keep those freq's set aside for users. My next point of curiousity would be: how wide-spread is that use? Just out on the west coast?

As for back-up frequencies: when I was with one of the local PDs, their back-up was cell 'phones (with the primary being the 800MHz trunked system).

 

[ai8o]

With the solar activity starting to increase again, I was wondering if many of these frequencies are still being used, or have the majority of them migrated to higher frequencies now?

In North Carolina, I occassionally hear car to car xmsns on the old 42 MHz channels.
Their dispatch, and most public safety activity; is now done on the VIPER (800 MHz) system, just low level chit chat on 42 MHz.

I'm not seeing 42 Mhz antennae on the new cars, so I guess that NCSHP 42 MHz activity will slowly fade out, as they replace the old cars.

I hope Solar Cycle 25 gets going soon; lately propagation is so bad, that I am starting to think that the next county is DX!

 

[SandBagger1]

I check this thread everyday even though I live in Australia.

2021 VHF Low Band Logs | Page 2 | RadioReference.com Forums

 

[mmckenna]

My next point of curiousity would be: how wide-spread is that use? Just out on the west coast?

No idea. I don't get much time to sit and just listen. You can run an FCC report on the spectrum and see who's licensed. But figuring out how much of it is actually used, who knows?

 

[mmckenna]

20,916 active licenses in the FCC database when looking between 25MHz and 50MHz.

There are a lot of different users in that spectrum, and the FCC database will not show any federal users, so the actual count would be higher.

I did another search on 25-50MHz with a 'grant date' range of January 01, 2021 until today. 424 entries. So someone is renewing or getting new licenses granted. To be fair, some agencies just automatically renew and never look at if the frequencies are actually being used. Often it's handled by some admin person somewhere and they've been told to not let anything expire. Since most public safety and government agencies are exempt from paying fees, there's really no one eager to get rid of the old stuff.

 

[nd5y]

To be fair, some agencies just automatically renew and never look at if the frequencies are actually being used. Often it's handled by some admin person somewhere and they've been told to not let anything expire.

Some even narrowbanded and added digital emission designators.

 

[ur20v]

Virginia DOT still active on the low band, though not much else licensed for it around here is.

 

[WB9YBM]

20,916 active licenses in the FCC database when looking between 25MHz and 50MHz.

To be fair, some agencies just automatically renew and never look at if the frequencies are actually being used. Often it's handled by some admin person somewhere and they've been told to not let anything expire.

That's what makes me think that if someone would see how many licensees are actually still using those frequencies, someone might realize these frequencies could be put to better use somehow and actually get used.

 

[GlobalNorth]

The fewer the civilian users on VHF-Lo, the better the Army, the Marine Corps, and the Navy like it.