Simplex Testing Comparisons

[DeoVindice]

If it's with a hand held, part of that is because the radio case makes a much better 1/4 wave counterpoise on UHF than it will on VHF. It's also easier to get an efficient antenna on a UHF hand held than it is with VHF.

That and I've found that UHF tends to penetrate some foliage better than VHF, even on mobile installs.

What foliage types have you experienced that with? I haven't heard that claim before and would love to add it to my bag of tricks.

I have also found VHF portables to be a serious compromise compared to UHF or 700/800. They just don't get out as well as you'd think based on receive performance, especially compared to a UHF portable. Throw a telescoping 5/8-wave on the UHF portable and it's just not even fair to the VHF unit.

I have an interesting anecdote regarding VHF portable effectiveness. About two months ago, my fiancee was one of the first on scene to a multiple-fatality vehicle accident on a rural highway near the county line. She provided what aid she could, since all but one of the casualties was dead on impact. I followed the incident on the sheriff's department's (analog VHF-hi) dispatch frequency and the responding deputies could not get out with their portables. Their mobiles worked just fine. I'm not sure whether this was an equipment issue, a training issue, or both, but their system as fielded was not cutting it.

Good portable coverage in this county can be achieved with one UHF high site and a single fill-in/backup low site. VHF-hi is "the way we've always done it" out here, but DPS does quite well with lower-density UHF high sites.

 

[mmckenna]

What foliage types have you experienced that with? I haven't heard that claim before and would love to add it to my bag of tricks.

In my particular case, it was coastal redwoods.

I have also found VHF portables to be a serious compromise compared to UHF or 700/800. They just don't get out as well as you'd think based on receive performance, especially compared to a UHF portable. Throw a telescoping 5/8-wave on the UHF portable and it's just not even fair to the VHF unit.

I think a lot of that depends on exact radio/antenna/design/situation. The known issues with lack of suitable ground plane on some VHF radios is a known thing. As radios get smaller, it becomes more of an issue. Sort of like why low band radios don't work very well.

I have an interesting anecdote regarding VHF portable effectiveness. About two months ago, my fiancee was one of the first on scene to a multiple-fatality vehicle accident on a rural highway near the county line. She provided what aid she could, since all but one of the casualties was dead on impact.

Wow. How's she doing? I only had to deal with a death one time, and it still troubles me.

I followed the incident on the sheriff's department's (analog VHF-hi) dispatch frequency and the responding deputies could not get out with their portables. Their mobiles worked just fine. I'm not sure whether this was an equipment issue, a training issue, or both, but their system as fielded was not cutting it.

Worst thing that ever happened to portable radios was the speaker mic coupled with the belt case.

 

[DeoVindice]

In my particular case, it was coastal redwoods.

Now that's interesting. Redwood needles look similar to juniper, which is all over the AZ and NM high desert. Sure enough, UHF has worked very well for us here.

I think a lot of that depends on exact radio/antenna/design/situation. The known issues with lack of suitable ground plane on some VHF radios is a known thing. As radios get smaller, it becomes more of an issue. Sort of like why low band radios don't work very well.

Agreed. We've used 43.04 a bit with TK-190s and they've been highly inconsistent. They're now backup radios.

Wow. How's she doing? I only had to deal with a death one time, and it still troubles me.

I appreciate you asking. She was shaken up for a couple weeks. We both work in a dangerous industry so we tend to compartmentalize traumas, for better or worse.

Worst thing that ever happened to portable radios was the speaker mic coupled with the belt case.

Now that's the truth, and they're antenna killers too. I started using Conterra and HPG radio harnesses/chest packs in the field after very unimpressive results with speaker mics and belt clips. I've been nearly 100% satisfied with that solution. The only time I use a speaker mic conventionally is during shaft entry where I have my ascender or descender clipped onto my harness's chest d-ring. The radio goes in a drop-leg pouch with a stubby antenna to keep it from getting beat up too badly. In that application, I only need a few hundred feet of range anyhow.

Don't even get me started on the misery that was a speaker mic on a low band portable clipped to a belt inside an all-steel telehandler cab. Effective range was about two hundred yards.

 

[KC3ECJ]

In my particular case, it was coastal redwoods.



I think a lot of that depends on exact radio/antenna/design/situation. The known issues with lack of suitable ground plane on some VHF radios is a known thing. As radios get smaller, it becomes more of an issue. Sort of like why low band radios don't work very well.



Wow. How's she doing? I only had to deal with a death one time, and it still troubles me.



Worst thing that ever happened to portable radios was the speaker mic coupled with the belt case.

Certain radios are just too heavy to begin with, nevermind having a speaker mic with it too.
I often end up taking the speaker mic off many radios.

If the radio is smaller or lighter however I might use a speaker mic, particularly if I have an outfit with epaulettes to put the mic on.

 

[vagrant]

Consider this....

When near a vehicle with only a handheld, place the handheld on top of the roof. This is when a speaker mic, or bluetooth mic can help to accomplish this. I have experienced the improvement using a tiny Yaesu VX3R while holding it in my hand with most of the ground plane in the direction of the VHF repeater. It even helps with a Moto APX7000XE using a BT mic...while stationary of course.

 

[KC3ECJ]

Consider this....

When near a vehicle with only a handheld, place the handheld on top of the roof. This is when a speaker mic, or bluetooth mic can help to accomplish this. I have experienced the improvement using a tiny Yaesu VX3R while holding it in my hand with most of the ground plane in the direction of the VHF repeater. It even helps with a Moto APX7000XE using a BT mic...while stationary of course.

I used an icom with a telescoping RadioShack scanner antenna and the speaker mic for the 6 meter band. The speaker mic acts as a good counterpoise for that band.

 

[KA0XR]

I used an icom with a telescoping RadioShack scanner antenna and the speaker mic for the 6 meter band. The speaker mic acts as a good counterpoise for that band.

A speaker mic seems like it would be a bit short as a counterpoise for 6m. I can see it providing that function on 2m/VHF high band. Did you do any side by side signal strength comparisons on 6m - speaker mic vs. no speaker mic? I have a heavy duty speaker mic for my VHF Motorola HT1000 with a direct metal connection to the side of the chassis that I should test with and without the speaker mic.

I have seen improved portable performance on 6m when using a long dangling wire (~36" rat tail - 54" was too long and didn't see much improvement) attached to the shell of the Diamond RH205 2m telescoping BNC antenna, but such an arrangement is rather cumbersome. I have a Motorola P200 for 6m but according to Motorola the speaker mic for this radio was only ever designed for use on UHF versions.

It makes sense that with compromise stubby public safety style antennas UHF portables would out-talk VHF portables due to the mentioned antenna gain and ground plane limitations. Keep these things equal and in my experience, especially where there is denser tree foliage, VHF would be superior in range. 2m vs. 6m mobile to mobile or base to base simplex might be a toss up that's harder to compare due to antenna & ground plane size differences to keep all things equal.