Mobile Radio choice: Dual band vs. 2m?

Martinjmpr

Wiffleball Batter
(First off, sorry about blowing up this sub-section with questions, but after a rather eye opening experience, I've decided to upgrade my communications ability in my F-150.)

I'm starting to realize my $25 purchased-off-CL-a-decade-ago used Kenwood TM-261A may not be the ideal radio for my truck, though it was fun to have a nice little cheap radio for a while.

So now I'm thinking if I want to get serious, I need to get a new radio, not a 20+ year old well used model that doesn't work 100% anyway.

I'll spend what I need to spend, but I don't want to spend MORE than I need. I also want to have a setup that is reasonably simple because in my experience, simple means "more reliable" and with fewer variables to go wrong or need adjustment and tweaking.

My current dilemma is: 2m or dual band (2m/70cm?) I absolutely want a 2m mobile (preferably at least 50W of power) in the truck, so it comes down to whether the cost/complexity/compromise of adding 70cm is worth it.

Cost: Adding the 70cm (440) band would add ~$100 or so to my initial cost (only because I'm not really interested in the Chinese cheap radios - I only want to do this once so I'll be going with a "name brand", i.e. Kenwood, Alinco, Yaesu, Icom, etc.)

Complexity & compromise: I only want to run one antenna so instead of having an antenna tuned to 2m, I'd have to have one that does both 2m and 70cm. But that means a compromise in terms of performance, correct?

If it matters, any mobile I get in my truck will be supplemented by a dual band HT (I have a Yaesu FT-50R that seems to work fine.)

I guess what I'm asking here is:

(1) For those of you that got 2m only in your mobile rig, did you later upgrade to dual band to add 70cm?

(2) For those that initially went dual band, do you find yourself using the 70cm band as often or more often than 2m? and finally

(3) If I went with a 2m only for the mobile, do you think a dual band HT would suffice for those times I wanted/needed to access a 70cm repeater or receiver?

Thanks!
 

Billoftt

Active member
2m/70cm antennas are not really a compromise. I am 100% positive Dave will explain the technicals in greater detail, but those two band resonate together. A very common antenna is one that is 1/2 wave on 2m and 5/8 over 5/8 collinear on 70cm.

As far as use on each band goes, I live in South Carolina. In the “regular” part of the state VHF is more prevalent because it pushed through the vegetation better whereas UHF will reflect off of leaves and stuff. Here I can go only 5 miles simplex on 70cm vs. 8-9 on 2m. Up in the mountains and in urban environments, the tendency for UHF to reflect and “bounce” becomes an advantage. Most of the repeaters in the Upstate mountains here are on 70cm. Consequently, it may be a good idea to invest in dual band.

As far as cost goes, I don’t think you are going to save much going with a dual band HT bs Mobile unit if you are staying with the Big 3 brands.


Sent by electrons or some crap like that.
 

Martinjmpr

Wiffleball Batter
2m/70cm antennas are not really a compromise. I am 100% positive Dave will explain the technicals in greater detail, but those two band resonate together. A very common antenna is one that is 1/2 wave on 2m and 5/8 over 5/8 collinear on 70cm.

As far as use on each band goes, I live in South Carolina. In the “regular” part of the state VHF is more prevalent because it pushed through the vegetation better whereas UHF will reflect off of leaves and stuff. Here I can go only 5 miles simplex on 70cm vs. 8-9 on 2m. Up in the mountains and in urban environments, the tendency for UHF to reflect and “bounce” becomes an advantage. Most of the repeaters in the Upstate mountains here are on 70cm. Consequently, it may be a good idea to invest in dual band.

As far as cost goes, I don’t think you are going to save much going with a dual band HT bs Mobile unit if you are staying with the Big 3 brands.


Sent by electrons or some crap like that.

Thanks for the input. In terms of cost, the biggest cost difference would be a 2m mobile at ~$150 vs a dual band mobile at ~$250. Both would be relatively low-end mainstream brands (Kenwood or Yaesu.) The HT I already have and AFAIK it works fine.
 

BigDaveZJ

Adventurer
I think the additional repeater capability of the dual band would be worth it. If I remember right, you're in Denver? The Thorodin machine near Boulder is 70cm and I can work it from my place in Centennial. There's a couple 70cm repeaters down south too, once specifically that I've used is the Badger Mountain repeater that's tied in to the network around Colorado Springs and Pueblo. I think all the ColCon machines are 2m though.
 

Billoftt

Active member
Have cruised the hamventions and local club swap-meets?

The reason why I ask is I usually see some more basic models (both 2m and dual band) in good shape for a bit cheaper. I usually see the Yaesu fanless VHF brick for $60-80 in my area when they pop up.


Sent by electrons or some crap like that.
 

DaveInDenver

Middle Income Semi-Redneck
I think all the ColCon machines are 2m though.
ColCon are all 2m. I like having 70cm and here on the western slope it's pretty useful. The question comes up pretty frequently and the answer IMO comes down to budget and intention.

There is no downside to having a radio cover multiple bands other than cost really. The radio isn't going to be larger or consume more power or anything. Dual band antennas are a little more expensive but there again there's not much negative to having one and never using 70cm. Won't be taller, for example.

But whether it's worthwhile depends on what you're trying to do and who you want to talk to ultimately. Look through Repeater Book and start looking at places you go and what repeaters covers you. Look at linked repeater systems, too. That's one reason 70cm is so useful out here, the linked systems often are mixed 2/70 or in some cases all 70cm.
 

Billoftt

Active member
There’s the Dave answer I was looking for.

On to the vote, I have a Kenwood TM-V71A and I constantly use the keypad on the mic. I have the function buttons programmed just right so that I can perform most function I need on the fly while driving and the keypad is just simple enough that I could use it without looking.
f5d0aab3a749afce6f29c4967055eadb.jpg

Then I bought an ID-5100...
b2580ea762acb559e96c19b4a510ccc0.jpg



Sent by electrons or some crap like that.
 

Gooseberry

Explorer
Ok a V71 Kenwood is a good radio and will do cross band so it can be a repeater if the others have a dual band. My new radio is a icom 7100 and it’s very full featured


Sent from my iPad using Tapatalk
 

Gooseberry

Explorer
There’s the Dave answer I was looking for.

On to the vote, I have a Kenwood TM-V71A and I constantly use the keypad on the mic. I have the function buttons programmed just right so that I can perform most function I need on the fly while driving and the keypad is just simple enough that I could use it without looking.
f5d0aab3a749afce6f29c4967055eadb.jpg

Then I bought an ID-5100...
b2580ea762acb559e96c19b4a510ccc0.jpg



Sent by electrons or some crap like that.

Oh I’m ordering one for the daily I’m tired of the woodpecker.


Sent from my iPad using Tapatalk
 
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Rallyroo

Expedition Leader
I second the Kenwood TM-V71A. It's a great fairly utilitarian radio without all the bells and whistles and other do-dads. I like that the Kenwood has separate volume and squelch knobs for the two bands; no need to dig through menus. If you don't plan on doing a remote display mount you can flip the display based on whether you want the speaker facing up or facing down depending on how you want to mount the full radio.
 

Martinjmpr

Wiffleball Batter
The TM-V71A is on my list for sure but a bit pricey. I do like all the features though.

At the other end of the spectrum are these two:

Yaesu FTM-7250R (according to at least one Amazon reviewer this is the replacement for the venerable FT7900.)


Icom IC-2730A


One thing I like about the Icom is the dual frequency display, which the Yaesu lacks.

Note that the above are Amazon links but both the Yaesu and Icom are available quite a bit cheaper at HRO, which is also local to me.
 

DaveInDenver

Middle Income Semi-Redneck
The TM-V71A is on my list for sure but a bit pricey. I do like all the features though.

At the other end of the spectrum are these two:

Yaesu FTM-7250R (according to at least one Amazon reviewer this is the replacement for the venerable FT7900.)


Icom IC-2730A


One thing I like about the Icom is the dual frequency display, which the Yaesu lacks.
The Yaesu is a dual band radio but single VFO (tuner). The Icom and Kenwood you show are dual band, dual VFO (tuner). It's nuanced difference but a dual (or more) band radio with only one VFO can cover multiple bands but only do one at a time. That would be like the old FT-7900 or the current FTM-7250DR. This is a step up from a mono band radio, which can only tune one band with a single VFO.

Most entry level HF radios are multi band single VFO. They might be able to tune on 10 bands but only one of them at a time. Even very expensive HF radios generally will only cover 2 of their 10 bands at one time.

A multiple VFO (which stands for variable frequency oscillator, it's vernacular for a tuner) is like having two radios inside one box. The closest Yaesu comparison at the moment to the TM-V71 is the FTM-300DR. The old FT-8800 or FT-8900 were most similar being analog FM only, but they're discontinued. The FTM-300DR adds Yaesu's System Fusion digital mode so it's not really an apples-to-apples comparison. If you're only after FM modes you're paying for something you don't need with the FTM-300DR.

For clarity, even having two VFOs isn't quite like two completely independent radios. These radios usually can receive on both bands at the same time but since they share an antenna connection they usually only have one transmitter so only one VFO can get access to the transmitter at a time.

Just a FWIW the TM-V71 is currently backordered at several distributors. So if you find one new it might be worthwhile jumping on it. It might only be a parts supply chain issue and temporary (for how long is anyone's guess there) or that Kenwood is preparing to replace it with a new model. The body of the TM-V71 and TM-D710 are shared and it might be time for Kenwood to update it to include a digital mode perhaps.

One thing also to mention is the FTM-7250 does not have a removable face AFAIK while all the other radios you mention do, which is a cost/benefit question. That might make mounting complicated depending on your expectation.
 
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Martinjmpr

Wiffleball Batter
The Yaesu is a dual band radio but single VFO (tuner). The Icom and Kenwood you show are dual band, dual VFO (tuner). It's nuanced difference but a dual (or more) band radio with only one VFO can cover multiple bands but only do one at a time. That would be like the old FT-7900 or the current FTM-7250DR. This is a step up from a mono band radio, which can only tune one band with a single VFO.

Most entry level HF radios are multi band single VFO. They might be able to tune on 10 bands but only one of them at a time. Even very expensive HF radios generally will only cover 2 of their 10 bands at one time.

A multiple VFO (which stands for variable frequency oscillator, it's vernacular for a tuner) is like having two radios inside one box. The closest Yaesu comparison at the moment to the TM-V71 is the FTM-300DR. The old FT-8800 or FT-8900 were most similar being analog FM only, but they're discontinued. The FTM-300DR adds Yaesu's System Fusion digital mode so it's not really an apples-to-apples comparison. If you're only after FM modes you're paying for something you don't need with the FTM-300DR.

The little Yaesu FT-50R I got used off of CL does have dual VFO's so I can see how that would be useful.

If I'm understanding correctly, on a single VFO transceiver like the FTM-7250R, I basically would have to choose a band, either 2m or 70cm, and make my frequency changes in that band only using the VFO. Whereas on a dual VFO radio, I can have one VFO for each band, which would allow me to monitor two frequencies at once, correct? But if, for example, I'm talking on VFO A (2m) and I hear a call on VFO B (70cm) that I want to respond to, wouldn't I have to do something to manually switch the transmitter from VFO A to VFO B? Or is there some way to do that automatically?
Just a FWIW the TM-V71 is currently backordered at several distributors. So if you find one new it might be worthwhile jumping on it. It might only be a parts supply chain issue and temporary (for how long is anyone's guess there) or that Kenwood is preparing to replace it with a new model. The body of the TM-V71 and TM-D710 are shared and it might be time for Kenwood to update it to include a digital mode perhaps.

So that's another can of worms, I see a lot of acronyms I'm not familiar with like C4FM and DSTAR. When you say "digital mode" are you still talking about voice communications or is this data communications, i.e. computer to computer? And if it is voice, what is the advantage of digital voice comms vs. regular FM voice?

One thing also to mention is the FTM-7250 does not have a removable face AFAIK while all the other radios you mention do, which is a cost/benefit question. That might make mounting complicated depending on your expectation.

I actually have a bracket for the radio right on top of the dashboard (a metal bracket that sits on the "cubby" in the center of the dash) so a detachable face isn't necessary to me although it may offer more mounting options.[/quote][/QUOTE]
 

DaveInDenver

Middle Income Semi-Redneck
The little Yaesu FT-50R I got used off of CL does have dual VFO's so I can see how that would be useful.

If I'm understanding correctly, on a single VFO transceiver like the FTM-7250R, I basically would have to choose a band, either 2m or 70cm, and make my frequency changes in that band only using the VFO.
I think you've understood but yes, you have a radio with a display and some knobs. You pick a frequency to use the radio and that can be any of the bands it's designed to work with but only one at a time. You can usually set up a scan list that will roll through frequencies and they can be from any band the radio supports, mix-and-match.
Whereas on a dual VFO radio, I can have one VFO for each band, which would allow me to monitor two frequencies at once, correct? But if, for example, I'm talking on VFO A (2m) and I hear a call on VFO B (70cm) that I want to respond to, wouldn't I have to do something to manually switch the transmitter from VFO A to VFO B? Or is there some way to do that automatically?
With a dual VFO radio (such as TM-V71) you have a display and knobs that let you use it with two frequencies at the same time. They can both be 2m, both 70cm, one of each. Depending on the radio design there might be two sets of controls (volume, squelch, tuning), a complete set for each side, or a single set of knobs with a button that selects with side the controls are operating upon.

For voice use all of these radios require you to pick a primary or secondary side, sometimes called an A or B or selected side. The verbiage will depend. The basic concept is you have one side that your PTT and probably the mic DTMF functions are controlling. That side will be the TX frequency. I'm not aware if any of them with automatically switch PTT to the side with activity with one exception, the TM-V71, and that's for a specific function.

The TM-V71 will internally switch sides if you designate one side as a "data" radio. This side will get the controls whenever the PTT line is asserted on the data port with the presumption this is coming from an APRS TNC (terminal node controller). It will momentarily hold off the non-data side that the mic PTT controls for so long as as it takes to transmit the data packet after which the data side is released.
So that's another can of worms, I see a lot of acronyms I'm not familiar with like C4FM and DSTAR. When you say "digital mode" are you still talking about voice communications or is this data communications, i.e. computer to computer? And if it is voice, what is the advantage of digital voice comms vs. regular FM voice?
In this case C4FM (System Fusion), D-STAR, DMR, P25, etc. are digital voice modes. Your voice is encoded and sent in digital over the air and decoded at the receiver.

It is different than digital data, like APRS. Which uses a modem to modulate data coming in from a device (like a user terminal) that gets transmitted as audio tones over the air and demodulated on the other end for another device that understands the digital stream (it's RS232 serial data).

Suffice to say digital voice is a bit of confusing Charlie Foxtrot. Yaesu's Fusion is relatively popular but in Colorado DMR is also fairly widely implemented. These two modes are both digital voice but not compatible, of course. In the case of D-STAR and DMR the repeaters are not analog, it's digital or nothing. Most D-STAR and DMR radios, though, can do analog still. With Yaesu's Fusion the repeaters are digital or analog and will switch based on input. So if you talk in digital the repeater transmits digital. Same with analog in, analog out. So they are backwards compatible.
I actually have a bracket for the radio right on top of the dashboard (a metal bracket that sits on the "cubby" in the center of the dash) so a detachable face isn't necessary to me although it may offer more mounting options.
Yup. When they don't accommodate removable faces the bodies are usually pretty compact and if you have a way to mount it then you're good. That is really just a statement in case it's important to your situation. I do prefer mounting the whole thing as one unit if you can swing it but modern interiors don't always lend themselves to it.
 
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Martinjmpr

Wiffleball Batter
Well, thanks to an unexpected vet bill I think plans for a new mobile are on the back burner at this point (poor puppy had badly infected ears and needed to be put under to have them cleaned out.) In any case, I'll continue to play with my ancient TM-261A and may try to install it in the truck myself this weekend.

For me, the toughest part of a radio installation is running the cables and wires through the firewall and running them neatly enough through the cab that it doesn't look like a spaghetti factory exploded in there. I want to hide my wires as much as possible for a clean, professional-looking installation.
 

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