46 Mhz frequencies in the same radio as VHF Highband frequencies

[critter449]

Hello.

I question. I have heard that low band frequencies cannot be programmed into the same radio as highband frequencies. I know that the Fort John Fire Department uses both lowband 46 Mhz frequencies as well as VHF Highband frequencies. Here is my example:

Alot of the time I will here one FTJ firefighter say to another one on 46.240 MHZ go to highband, and then soon after that I will hear them talking on either 151.400 MHZ or 155.055 MHZ.

I do not remember who told me that lowband frequencies cannot be programmed into the same radio as highband frequencies.

In closing is this true or not. Thanks a bunch.

 

[W0JJK]

That is correct low band can not be programmed in a high band radio.

But some radio manufacturers have the abiltity to put two remote mounted radios on different bands like a Low Band and a UHF on one control head.

 

[freqseek]

If the scanner covers both hi & low then you would be able to program both in, if you are talking about a transceiver it would depend on that particular radio whether it was mfg to cover both, and a transceiver that covered both would require a dual band antenna or 2 antennas, one for high & one for low band and a duplexer between the radio & antennas(to seperate the 2 bands), to keep a low SWR to prevent damaging the radio.

 

[critter449]

Wow,

Thanks for your responses. I really appreciate all of your help.

Have a good one

 

[58006]

Both Vertex and Kenwood offer a dual band application taking two radio decks and wiring them into a single control head and the act as if they are one radio. They have their advantages and disadvantages.

 

[critter449]

So what does everyone think is happening here.

A. Are they using 2 radios one programmed with their low band 46 MHZ frequencies and the other programmed with their VHF Highband frequencies.

B. Are they using one radio capable of having both 46 MHZ and 150+ MHZ frequencies programmed into it.

What does everyone think.

 

[DaveNF2G]

You don't have to speculate. Go to the fire house and look in the trucks.

 

[critter449]

You don't have to speculate. Go to the fire house and look in the trucks.

I did not know that you could do that without getting into trouble.

I will see what I can do.

 

[DaveNF2G]

Well, you have to go when someone is actually in the firehouse. You can't just walk in any time on your own. But firefighters are generally happy to show off the trucks and equipment.

 

[critter449]

Well, you have to go when someone is actually in the firehouse. You can't just walk in any time on your own. But firefighters are generally happy to show off the trucks and equipment.

Cool

Anyway of finding out frequencies by looking in a fire truck. Do they have a list of frequencies posted anywhere in the fire truck that is out in the open or are there frequencies already programmed into there radios and no frequency sheet to be found in the fire truck.

Thanks Dave

 

[DaveNF2G]

The end users (fire crews) have no reason to know the frequencies, just which channels to select for what purposes. The only mobile radios you are likely to see accompanied by frequency lists would be ham radios, because a ham is required to know on what frequency he/she is transmitting.

Base stations should have a license posted nearby that will have frequency information. The catch is that, if they are operating under authority granted under a countywide or regional license, then they don't have to have a license of their own.

I can anticipate the next question: How do I find out what frequencies they are using?

There are several ways:

- search the "public safety" bands with your scanner

- use the Close Call, Signal Stalker, or Sweeper function if your scanner has one - for this you need to be close to the unit that is transmitting

- check the RRDB (I presume you have already done this)

- check any locally maintained scanner websites or listings

I think your original question was more concerned with the type of radios they are using, and the only ways to discover that are either to ask someone who uses them or to view the radios yourself directly.

 

[Spec]

Just to add to Dave's post you may also just take a look at the antenna. Sometimes that's a dead giveaway . I have used systems that transmitted on vhf-lo and received on vhf-hi. This was due to the mountainous region we were working with. Two different ant. for one radio system.

 

[silverbk]

If they are like 90% of upstate NY fire departments then they are migrating off low band (46 mhz). but still need 46 mhz to talk to county and neighbor departments.

They most likely simply installed another mobile in all their trucks, and their officers will be carrying another portable. To my knowledge there are no commercial radios capable of transmitting on lowband and VHF high. They may have a dual deck setup, but with low band being used for legacy purposes only I would doubt it. It's really irrelevant because you will be able to monitor them in the same fashion regardless.

There are many departments that insist on using their "own" or "house" frequencies because the regular fireground frequencies are not good enough for them. Personally I think the practice should be banned so you don't have a situation like the charter circle fire in Ossining again. If they have their own frequencies they are usually licensed for them and you can look them up in the FCC database.

 

[gralston73]

The Thales Liberty portable radio transmits on VHF-Hi, UHF, and 700/800 MHz...why wouldn't they have also included VHF-Low???

Thales Liberty LMR

 

[silverbk]

The Thales Liberty portable radio transmits on VHF-Hi, UHF, and 700/800 MHz...why wouldn't they have also included VHF-Low???

Thales Liberty LMR

A quote from the first page of your link:

The Thales Liberty portable radio operates on analog, P25 conventional and P25 trunking systems in all public-safety frequency bands — UHF (136-174 MHz), VHF ( 380-520 MHz), and 700/800 MHz.

I would like to clarify my statement. There may be a radio capable of doing this like a military radio (MIBTR) or a Wolfsburg designed for a helicopter, But I know of no FCC approved commercial models.

The reason that Thales didn't include lowband are two fold. It is very hard to do (you end up with a huge front end on the radio) and it is not economically viable. Besides Fire departments in upstate New York, HAMS, and the old cordless phones, there are not a lot of potential customers of low band equipment.

Lowband works great in ideal weather conditions, but horrible in inclement weather. It also has significant trouble in developed areas with buildings and other infrastructure. It also has problems with frequent band openings. Ever notice that right before it rains you start hearing stations from other states? That's due to the band opening and the signals getting to you by hopping or skipping. From Westchester County we routinely hear stations in Georgia and Alabama.