2m HAM (Dual): Monitor two 2m frequencies?

woytovich

Observer
I see most "dual" are "144/440".. Will some/any/most/all "dual" radios allow monitoring of two 2m (144) frequencies vs 144/440?
 
I believe such a feature exists in some form. Some radios may allow extended reception modification (i.e. a hack) while others may have a "priority" frequency which then sequentially scans , or flip-flops a pair of programmed frequencies and then stopping when the squelch is broken.
 

NatersXJ6

Explorer
It has been a very long time since I’ve programmed anything on my radio, but my first thought was also to scan the programmed frequencies. If you scan just 2-5 frequencies, it goes so fast you are essentially monitoring them all.
 

woytovich

Observer
I understand that you are both saying there are work-arounds to achieve this function. I'm wondering if there are specific radios that allow this as a built-in feature.
 

kidphc

Member
I see most "dual" are "144/440".. Will some/any/most/all "dual" radios allow monitoring of two 2m (144) frequencies vs 144/440?
Not quite sure what you are asking. Or I must of had a stroke again.

My ftm 400, as well as any true dual vfo dual bander ahould be able to.. For instance will do the following.

A: scan memory bank on vfo a and dual watch a priority channel (for me 2m nat sinplex).

B: it can on vfo b. Be on aprs ( a 2m frequency). Static on a 2m frequency .

The ftm400 only has one c4fm encoder, on vfo. The 300,500 can do c4fm on both vfo a and vfo b.

But if I read your question right. The answer is if it is a true dual vfo radio. It should be able to scan whatever you program and monitor you want. In fact fake dual vfo radios (lumping the anytone779/db20g radios into it). It will do it as well.




Sent from my SM-S901U using Tapatalk
 

woytovich

Observer
Not quite sure what you are asking.
To try to clarify (and it is probably obvious that I am a relative newbie):
When I'm out wheeling at an event and there are two groups, each on their own 2m frequency, I want to be able to hear what is going on on both. By "hear" I mean I don't want to miss an important transmission.
I do understand about scanning multiple frequencies, waiting for a transmission. Scanning back and forth between 2 frequencies on a single band radio will work I think. I guess I'm wondering how/if a "true" dual band would better serve that purpose?
 

kidphc

Member
To try to clarify (and it is probably obvious that I am a relative newbie):
When I'm out wheeling at an event and there are two groups, each on their own 2m frequency, I want to be able to hear what is going on on both. By "hear" I mean I don't want to miss an important transmission.
I do understand about scanning multiple frequencies, waiting for a transmission. Scanning back and forth between 2 frequencies on a single band radio will work I think. I guess I'm wondering how/if a "true" dual band would better serve that purpose?
Yes, in that case yes, a true dual vfo radio would be able to listen to both frequencies at once.

Problem becomes when wheeling or any semi intense activity is occurring. Which vfo was that transmission on? Not such a bad deal if it has 2 separate speaker out puts. Then you physically place each speaker in a different location.

Ie one on the driver side and the other on the passenger side. Or a speaker on the front roll bar and the other to passenger side of the driver.

In my ftm400 they output on the same speaker, so a physical lookup at the head is required to figure out which vfo just had a transmission.

Sent from my SM-S901U using Tapatalk
 

DaveInDenver

Middle Income Semi-Redneck
Dual can mean a couple of things.

One is it can mean the radio covers dual (meaning two) bands, which as you notice most commonly is 2m (144MHz) and 70cm (440MHz), on which it can receive and transmit. Some radios will be called triband and quad band or multi-band if they can work on 3, 4, or many bands.

The other reference is that the radio has dual receivers or transcievers (both receive and transmit) is in effect two (dual) radios in one physical box.

It's only the second type that can do two things at once. And the ones that can almost always can do two 2m or two 70cm or one of each at the same time.
 

DaveInDenver

Middle Income Semi-Redneck
Does the radio "stay" on the frequency that broadcast last... for some period of time?

If you want to reply how do you select the frequency to broadcast on?
Radios that are scanning will stop on a frequency. You can usually adjust the dwell time, how long the radio stays on the frequency when it stops. You can make it stop scanning completely, restart when the activity stops, restart after some set period (perhaps 10 seconds). Some will not resume scanning if you push the PTT button and transmit. Some require that you manually stop scanning before it'll let you transmit. All this depends on the manufacturer and you have to read the manual.
 

DaveInDenver

Middle Income Semi-Redneck
So what do I look for to know which is which? What in the specs will be the tell?
Read the spec sheet. What radios are you considering? It's somewhat obvious when you look at a radio. If it displays two frequencies it's probably (but not always) a dual transceiver. The technical name for a radio that operates on two frequencies at the same time is "dual VFO" where VFO means variable frequency oscillator. The VFO is the actual device inside the radio that lets you pick a frequency so for a radio to physically be able to tune two different frequencies it needs two VFOs, meaning two tuners, to do it.
 

DaveInDenver

Middle Income Semi-Redneck
For example here's a couple of radios.

The FTM-500 is a dual band (2m and 70cm), dual VFO (two tuners) radio.


"True Dual Band Operation, C4FM/C4FM Digital D-D Dual Receive"

ysu-ftm-500dr_xl_mid.jpg


The FTM-6000 is a dual band (2m and 70cm), single VFO (one tuner) radio.


ysu-ftm-6000r_xl_mid.jpg
 

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