portable output

bud_mot · Post by **bud_mot** » Thu Jan 01, 2004 3:57 pm

Is 5 watts the most any portable (handheld) radio outputs? Does the military or three letter agencies have things that do more?

k4wtf · Post by **k4wtf** » Thu Jan 01, 2004 4:22 pm

I've seen 7w out of consumer portables. Typically, most tactical radios are going to be 5w or less though from my experience.

John

kc7gr · Post by **kc7gr** » Thu Jan 01, 2004 4:23 pm

I've seen the older Motorola 'Lunchbox' radios (PT300, 400, 500) put out 8-10 watts for the VHF model. Also, the UHF Apcor radio came in 2 watt and 12-watt versions (yes, it really did make that kind of power). I've also seen VHF HT600's make it to 7 or so.

The limiting factors are what you consider to be "portable," how much battery capacity you have, and what the final TX amp is rated for.

Cam · Post by **Cam** » Thu Jan 01, 2004 4:26 pm

And then the fact that you hold the thing right in front of your face when TX. I don't think I'd want a 110 watt handheld, even it there was a battery that would let me use it.

Cam

Wes · Post by **Wes** » Thu Jan 01, 2004 7:14 pm

My first Radio........

Good Ole' MT500 VHF.

Would do 8 Watts EASILY and had more to spare. But, the little green fuse in the battery compartment would blow if you turned it up much past 8. So, 5.5 to 6 was always enough for me.......

Wes

bud_mot · Post by **bud_mot** » Thu Jan 01, 2004 8:32 pm

The limiting factors are what you consider to be "portable," how much battery capacity you have, and what the final TX amp is rated for.

Yeah, that all makes sense. I may be off base but it just seems that most modern handheld radios never have a power output of more than 5 watts (and then only VHF). This got me wondering if it was due to FCC safety regs or practical issues/technical limitations. Then I wondered if non FCC regulated folks like the government/DoD had 30 watt handhelds or if they simply don't exist due to said practical limitations.

k4wtf · Post by **k4wtf** » Thu Jan 01, 2004 8:41 pm

The limits are based on RF exposure. You don't want to be stairing into 7-10W at UHF and you especially don't want to do that with 800Mhz and above, unless of course you're ALREADY blind and even then, I wouldn't want to risk the exposure.

John

larryepage · Post by **larryepage** » Fri Jan 02, 2004 10:19 am

I do not have the regulations in front of me, but I believe that there is a blanket maximum of 7 watts for any handheld radio. This is probably somewhere in Part 1 of the rules. As for licensing, what you will generally see is

7 watts for low band
5 watts for VHF
4 watts for UHF
2 or 3 watts for 800/900.

Specs for current and recent Motorola and other portables also seem to follow these limits. This is probably also a practical limitation...since PAs get progressively less efficient as operating frequency increases, all of these power levels represent generally the same current draw from the battery.

Regards,

Susan157 · Post by **Susan157** » Fri Jan 02, 2004 11:23 am

We Have Seen A Lot Of Vhf Portables Go To 7.5 Watts.

The HT1000 Has 2 Power Levels And The GP350/GP300
Have 3 Power Levels And We Set A Few Up For The
SAR Groups That Need The Extra Power.

"But We Tell Them ONLY USE IT FOR VERY SHORT
PERIODS. It Appears Ok To This Point.

P.S. Hard On Amps And Batteries.

Jim202 · Post by **Jim202** » Sat Jan 03, 2004 7:55 am

Susan said "Hard On Amps And Batteries".

She hit the nail right on the head. It boils down to being practicle. Just how heavy do you want the radio to be? Just how big are you willing are you to lug around a heavy brick all day?

The higher the output power, the shorter time the battery will last. The 5 watts that most of the portables are rated at didn't just happen. It came over time and trials of just what was practical.

You can push the output on a portable. What are you gaining? Not much. Don't forget that you only gain 3 Db of power output every time you double the RF power. Going from 5 watts to say 7 watts just heats up the PA and will more than likely blow it over time.

I guess it depends on how deap your pocket book is for paying the radio repairs.

Jim

w7com · Post by **w7com** » Sat Jan 03, 2004 8:07 pm

If you really need to increase your range improve your antenna. They don't call them rubber resistors for nothing, son.

bud_mot · Post by **bud_mot** » Sat Jan 03, 2004 10:36 pm

Just to clarify- I do not need more power or range. 4 watts @ UHF works fine for me. I was just curious how these power values came to be. Thanks all.

70351 · Post by **70351** » Sun Jan 04, 2004 12:02 am

Susan157 wrote:Hard On Amps And Batteries.

A Beavis & Butthead thought comes to mind . . .

Randy

doi · Post by **doi** » Sun Jan 04, 2004 6:00 am

a friend of mine had a vhf ht600 (i think-not sure) that he modified (changed pa and more) to put out 15w. battery life was great on rx. but dare transmit.... it would last max 2 hours in actual use. anyway i don't remember what capacity his battery was.

and one more thing: if you would not hold the radio firmly and touch with your palm some of the metal casing (e.g. push ptt with one finger while holding it from the other side with another finger) you would get BURNED.

nmfire10 · Post by **nmfire10** » Sun Jan 04, 2004 6:46 am

Ah, just hook a car battery up to the duty belt. You'll be fine.

portable output

portable output

There are stronger ones, yes...

A Lot Of Vhf 7.5 Watts"Susan157"

Re: A Lot Of Vhf 7.5 Watts"Susan157"

Re: A Lot Of Vhf 7.5 Watts"Susan157"