What will become of VHF-low?

[tvdxer]

What will become of 30 - 50 MHz?

This band is used by highway patrols, taxi drivers, and some businesses. 49 MHz was once used by practically every cordless phone until they started to go to 900 MHz (and then 2.4 GHz, and then 5.8 GHz). It offers a longer simplex range than higher frequencies at the expense of large antennas. However, everything seems to be going digital these days, and I've never heard of APCO-25 or any digital voice method on VHF low. Rather they tend to use trunked networks with lots of closely-spaced repeaters on 700 or 800 MHz.

So then the question is: what will become of this band that is so loved by "skip" enthusiasts?

 

[haleve]

The good die young.

 

[zz0468]

I haven't heard that anything is going to happen to it. There are still a lot of users who feel that low band is the only band that will do what they need to do. It's not subject to any refarming or narrow banding mandates. It's not really useful for any sort of broadband use, so it's not going to become yet another cellular band. Just status quo, so far as I've ever heard.

 

[phillydjdan]

Perhaps the freebanders will take it over...

 

[b7spectra]

Not many users like the low band because of the size of antenna you need. I really miss seeing those 100" whips on the old CV's. Ever see a rubber duckie on a portable? You could poke your eye out from your belt!

The sound quality of low band is great. You get to hear all kinds of noises in the background when someone keys up. THAT was radio!

 

[ab3a]

We still use it at work. So do the state police. When you're dealing with utility trucks, you NEED survivability. The nice thing about a low band VHF rig is that with 100 watts of power at the mobile and 300 watts of power at the base station, you can talk over ground-wave distances of 100 miles or more with NO OTHER INFRASTRUCTURE.

This makes it exceedingly useful for disaster recovery. I sure hope it stays pretty much the way it is. Those trunked systems sure are nice, but they're heavily reliant upon infrastructure that might not be there when we really need it. Just ask the police in New Orleans what their experiences following Hurricane Katrina were like...

 

[K9WG]

American Red Cross still use it for nationwide disaster communications. (47.42Mhz)

 

[fdcaptjd]

I grew up onVHF low. The Fire Dept I work for was on 46.36 when I started. 25 years ago.

I agree no repeated/2.5 kc deviation audio comes any where close to sounding like simplex 5 kc.

My first radios were a GE Mastr Pro and then a solid state Mocom 70.

The Mastr Pro would actually dim my headlights when transmitting.

You had to have a tune-up now and then, but they did talk.

Best Regards,

JD

 

[WA1ATA]

Many cities and counties also have licenses in the VHF low band. Typically for communications between Emergency Operations Centers.

Like ab3a noted above in reference to its use by utilities, the VHF low band is well suited for direct simplex point-to-point communication that doesn't rely upon any infrastructure.

Exactly what is needed by cities and the Red Cross during major disasters, and what is needed by electric utilities during major power outages.

 

[haleve]

Low Band

American Red Cross still use it for nationwide disaster communications. (47.42Mhz)

www.freqofnature.com/frequencies/ca/redcross.html

 

[eriepascannist]

Around here all the fire departments with the exception of the city of Erie still use VHF-low. Erie county is on 33.88 and Chautauqua county is on 46.1. Many of the rural counties/areas up here still use VHF-low. I have not once heard a problem with the radios. So, for areas out in the sticks like mine, I think that as long as VHF-low is doing what the users need, then why switch? We also have utilities, road crews, and EOC's that use VHF-low for primary communications.

I personally think Chautauqua county will be on 46.1 for a long time to come.

 

[n5ims]

Those trunked systems sure are nice, but they're heavily reliant upon infrastructure that might not be there when we really need it. Just ask the police in New Orleans what their experiences following Hurricane Katrina were like...

Actually the old New Orleans EDACS system survived the hurricane pretty well. The infrastructure was nearly intact (one microwave link was blown off course so the New Orleans East site went into stand-alone mode but the rest of the system worked pretty well until the enforced lockdown of the affected cities & parishes which was enforced through uncoordinated activities by various agencies prevented folks returning to evaluate the system and work on the critical issues that finally killed it. These issues included evaluating the sites (where several of the issues could've been found earlier and failures prevented), fuel deliveries prevented (they should've been escorted into the city, not turned around at the checkpoints), etc.

This is a good write-up from the consultant that built and maintained the system prior to, during, and after Katrina --> TUSA Consulting

 

[ab3a]

Infrastructure Failures

n5ims makes a valid point: the system itself can be quite survivable. But the infrastructure that supports it can still fall on the floor.

That's what I was getting at. Even if the system itself was built to be survivable, it has to be maintained. The confusion following a terrible event like this has to be seen to be believed. The problems they had were largely ones of fuel, transportation, public safety, and the like.

You cut through that confusion by maintaining a direct connection to the field that depends upon as little as possible. If Low Band VHF services didn't already exist, they would have to be reinvented.

 

[DickH]

... I think that as long as VHF-low is doing what the users need, then why switch?
I personally think Chautauqua county will be on 46.1 for a long time to come.

Why switch? Because some slick salesman will come along and convince the powers that
be, who likely know nothing about radios, that Lo Band equipment is no longer made and they need to go to a fancy 700MHz trunked system costing millions of dollars.

 

[DaveH]

Despite great advances in technology, there are physical limitations of
the lower bands which can't be overcome; easily or at all. The long
wavelength makes for big antennas, and shorter antennas are inefficient.
Anyone seen a lowband HH with foot-long rubber antenna?

Other drawbacks include high electrical noise; and propogation, including skip,
plus poor penetration into buildings due to long wavelength.

Lowband will continue to have limited traditional use with established
systems. Military will continue to use it, and that's an area that's not in
decline.

Perhaps low-power short-range applications will be developed, such as
RFID.

Dave

 

[kb2vxa]

Did I ever see a low band portable? Sure have, back when portables had carrying handles that doubled as cradles for telephone type handsets with a PTT button. I saved one from destruction by a PA fire department upgrading and modified it for 6M, nice 10W output. Yeah, I'm an old fart.

 

[APTN]

Why switch? Because some slick salesman will come along and convince the powers that
be, who likely know nothing about radios, that Lo Band equipment is no longer made and they need to go to a fancy 700MHz trunked system costing millions of dollars.

I would imagine the slick salesman does a play a role. I also suspect that the ability to accommodate multiple users also motivates agencies to opt for the higher frequency trunked systems. Nonetheless, if the agencies are smart, they will retain low band as a back up for reasons previously mentioned.

It's a shame that the manufacture of low band equipment has declined if not totally discontinued.

On a side note, in my area THP still uses low band.

 

[KC4RAF]

There will always be a need for the VHF-low band.

Just do some research, you'll see that this band has really good to great distance, punches through and skips a long way. There's more to the low band that meets the eyes, err ears...

 

[NKG]

Digital VHF Low Band

What will become of 30 - 50 MHz?

This band is used by highway patrols, taxi drivers, and some businesses. 49 MHz was once used by practically every cordless phone until they started to go to 900 MHz (and then 2.4 GHz, and then 5.8 GHz). It offers a longer simplex range than higher frequencies at the expense of large antennas. However, everything seems to be going digital these days, and I've never heard of APCO-25 or any digital voice method on VHF low. Rather they tend to use trunked networks with lots of closely-spaced repeaters on 700 or 800 MHz.

So then the question is: what will become of this band that is so loved by "skip" enthusiasts?

Actually, a company called DETRACOM and based in France, developed digital communication for VHF Low Band. Their technology is called E-DMR and it is also available for VHF High band.

DETRACOM | Private Mobile Radio

 

[eportel6607]

We use low band 42-50. Two state wide networks. Only use a frequency band for what it's good for and nothing more. Low band is great for long hops. It's best for mobile/base use and not so great using it as a portable...not because of the radio but because of the very inefficient antenna. We use loaded quarter wave antennas (Larsen NMO40) and for base and infrastructure we use a Laird BR4 Ringo.
For portables we have a "in house" custom made Extender system on each mobile and base. The portables can either be UHF or VHF. (UHF portables if you have a lot of city/in-building situations and VHF if you do a lot of outdoor work like Search/Rescue, etc.). The portables can be set to 1 watt of power, saving massive amounts of battery power. The Extender system has a built in diplexers that isolates the extender receiver from the overloading of the mobile low band radio. We use a quarter wave antenna for the extender system on the vehicles. Now the 1 watt portable radio "hears" whatever the mobile receives and the 1 watt portable radio...transmits with the authority of the mobile radio (60 to 110watts with a very efficient antenna) since it's actually trigging the mobile radio. In this case the portable is being used more as a "remote" to the mobile radio rather than a portable "version" of the mobile radio. The difference in performance rivals commercial high end voting/comparator systems used by most government public safety agencies for a fraction of the cost. So our portable radios have the exact same performance as out mobiles and base radios...but have the advantage of being in a more suitable band (VHF Hi or UHF) for portable use. It's the best of both worlds.