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Author Topic: Is there a market for full size HTs any more?  (Read 4310 times)
SMAUG
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« on: July 03, 2013, 11:44:55 AM »

I was just thinking it would be nice to have an HT that would put out 10-15 W instead of 5 W.

In my experience with my old 2m mobile rig compared to an HT, there is a big difference in the ability to hit a repeater between 5 W and 15 W.

All of today's HTs seem to be focused on miniaturization. The battery packs all go on the back, and power is limited to 5 W. This is to make them "handy." Bigger batteries = thicker radios.

This is all fine and well. But how about the option of a "Powerhouse HT?"  Go back to the old form factor, in which the radio is the top part, and the battery is the bottom. Then, more battery = taller, not thicker. It still would fit the hand well.

For example, on my Icom IC-V80, (basic 2m, 5.5W HT) if the battery case took 12 AAs instead of 6, and the heatsink was made larger, I bet it could easily be made to transmit at 10 W. Maybe even make the case of the radio out of cast aluminum, with fins, to act as a heatsink? Battery pack goes on the bottom, so it would be a couple inches taller. Include the stock duck, but also a 1/2 wave telescopic antenna. Price it at $150 with battery case and no charger. 10 W out on the telescopic antenna would be a marked improvement from 5 W out with a stock duck.

What do you guys think, would it sell?

Or is there maybe an issue with the higher power level being sent out through the antenna close to one's head?

I bet if the marketing was done right, it would be a runaway success, and we would suddenly have a new class of HT.

Maybe even re-visit the idea of a cradle for mobile use that has connections for power, antenna, and speaker/mic.

This is kind of along the same line of thought of current notebook computers. For a while, they just kept getting smaller. But then, some folks realized there are advantages to a larger, but still portable laptop: Bigger screen, bigger keyboard, more processor power, room for a BlueRay ROM drive, etc.
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Jeremy (KC9ZHE)
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"America will never be destroyed from the outside. If we falter and lose our freedoms, it will be because we destroyed ourselves."
-Abraham Lincoln
K1CJS
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« Reply #1 on: July 03, 2013, 01:41:26 PM »

One thing it has to do with is efficiency and the output power generating excess heat.  5 watts seems to be the top end because anything more with someone transmitting an excessive length of time, and the HT would become too hot to handle.  Most HTs will 'fold back' power if the unit gets too hot anyway.

There are some HTs that have a slightly greater output depending on the power fed into them.  For example, the Icon T7H that I use will output 7 to 8 watts of power if you use the car connector cord to feed it from the cigarette lighter/power socket of your vehicle, but it will fold back power after a minute or two because of the heat generated by the output stage.  You would think a longer 1/4 wave antenna would stop that from happening, but it usually does not.  Sure, you could try to make it happen, but then the costs of making the unit start to go up drastically--as does the sales price.

When you get up into the 10 to 15 watt area, the heat sink required would be larger than even an older handheld unit--even under intermittant use.  It just isn't feasible for the HT makers to try since a HT is generally an inefficient transmitter with a receiver that isn't all that much better.  It's more cost effective for the radio manufacturer to step up to a mobile radio at that point.
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WB2WIK
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« Reply #2 on: July 03, 2013, 02:04:50 PM »

I think "no market for it" at all.

If higher powered hand helds were cheap, I don't think any manufacturer would sell any more of them than they do the current models.

Heat is a huge problem.  At 50% efficiency, 10W out = 10W dissipated in the final stage.  As a test, place a 15 Ohm 10W resistor in a box you can easily hold in one hand, and apply 12V to it for a few minutes, then see if you can touch the box (or if its exterior is plastic, if the box hasn't started to melt).

The "7W output!" small hand helds on the market all cannot run that for more than a minute or so of transmit time, so it's just marketing tomfoolery.

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SMAUG
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« Reply #3 on: July 03, 2013, 02:28:46 PM »

Heat is a huge problem.  At 50% efficiency, 10W out = 10W dissipated in the final stage.  As a test, place a 15 Ohm 10W resistor in a box you can easily hold in one hand, and apply 12V to it for a few minutes, then see if you can touch the box (or if its exterior is plastic, if the box hasn't started to melt).
This would be equivalent to 0% efficiency, since all of the energy is changed into heat.

At 50% efficiency, 10 W out = 20 W in. Is 50% efficiency typical for an transmitter? Sounds kind of terrible...


Quote
The "7W output!" small hand helds on the market all cannot run that for more than a minute or so of transmit time, so it's just marketing tomfoolery.

If they claim 7 W output without any fine print, then I agree. But if they reference a duty cycle, and say this is only with a 13.6 VDC source capable of 10A or something, then I think it's fair game. Also, remember that I'm not talking about a small HT, but a big one. Think HTX-202-sized or maybe even Motorola Saber-sized


Quote
(K1CJS)When you get up into the 10 to 15 watt area, the heat sink required would be larger than even an older handheld unit--even under intermittant use.  It just isn't feasible for the HT makers to try since a HT is generally an inefficient transmitter with a receiver that isn't all that much better.  It's more cost effective for the radio manufacturer to step up to a mobile radio at that point.

Well, there are options:

- Make the HT larger in some way
- Use an aluminum enclosure, or at least a bit aluminum heatsink for the amplifier stage that gets hot
- Place the heatsink in a place were the HT is not held normally, like maybe right on the face of it
- Use forced air cooling, and give up on all the claims of waterproofness and mil-spec construction.
- Discuss duty cycle

Right now, Yaesu has a battery operated, all-band mobile. Only 5W, but it can be carried around on one's person.

This would be between a larger HT and this battery-powered mobile. Maybe it would be marketed as a 'hand-held mobile radio' or a 'power talkie' rather than a 'handy talkie.'? It would be the size of a portable CB from the early 90s, probably. I have one at home that is 4W output and will take 10-12 AAs. I'm pretty sure it is less efficient than a modern ham radio, as it would suck through a set of alkalines in shorter order, on high power...

Is it for everyone? No. But neither is anything else. Some guys won't touch ANY HT. Some guys like D-STAR and some guys don't. Some guys are not interested in mobile HF, but enough are that there is apparently a market for it.
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Jeremy (KC9ZHE)
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"America will never be destroyed from the outside. If we falter and lose our freedoms, it will be because we destroyed ourselves."
-Abraham Lincoln
SMAUG
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« Reply #4 on: July 03, 2013, 02:29:41 PM »

I think I will write to Icom, Yaesu, Alinco, and Kenwood about the idea.

I will do them a favor and not even patent the idea yet. Wink
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Jeremy (KC9ZHE)
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"America will never be destroyed from the outside. If we falter and lose our freedoms, it will be because we destroyed ourselves."
-Abraham Lincoln
NO2A
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« Reply #5 on: July 03, 2013, 02:37:03 PM »

Not only would the ht run hotter,but the rubber duck would get really hot. The duck on my F6 Kenwood gets plenty warm with 5 watts or less. I can`t imagine 10-15 watts,it would simply be too hot to hold. BTW,if you ever want to try something,remove the battery from an TH-F6 ht,then run it off 12 volts while keying it for a minute or two. I`ve done it. Almost burned my fingers,no joke.(the back without the battery is bare metal)
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AG6WT
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« Reply #6 on: July 03, 2013, 06:09:17 PM »

IMHO, it wouldn't sell. In addition to the problems already mentioned you would have an HT that has a very limited talk time.

The biggest problem with HT's is not the low power output. 5 watts is plenty to hit local repeaters. The problem with HT's is that the rubber duck antenna is very inefficient. A short run of coax to a roll-up j-pole or 1/4 wave mag mount on a cookie sheet will help you to get out much more than another 5 watts. If that is still not enough, getting the antenna outside, high enough for LOS is what you require.
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K2OWK
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« Reply #7 on: July 03, 2013, 09:56:46 PM »

How well would your brain hold up with 15 watts next to it at 2 meters? We are not sure about 5 watts or even the flea power of cell phones. Want to take a chance? I am sure the manufactures of these devices do not. Big law suits.

73s

K2OWK
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K1CJS
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« Reply #8 on: July 04, 2013, 07:07:49 AM »

How well would your brain hold up with 15 watts next to it at 2 meters? We are not sure about 5 watts or even the flea power of cell phones. Want to take a chance? I am sure the manufactures of these devices do not. Big law suits.

For years, there have been 100 + watt VHF mobiles that have been used with the antennas within four feet of the users--and there hasn't been even one report of harm to those users from them.  Who?  Police officers and public service workers--people exposed every working day to the use of two way radios.

Cell phones operate up in the microwave range, wich might--MIGHT--cause damage, but there again, cell phones use milliwatts, not watts, and microwave ovens use over 700 watts to cook food.

RF exposure limits have been put in place by FCC lawyers, not engineers or scientists--and those limits are over-blown, just like other 'limits' placed in this, our over litigious society.  Helping spread this foolishness--even if the government condones it--isn't doing anyone any favors.  Hams should know better.
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K0JEG
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« Reply #9 on: July 04, 2013, 11:02:16 AM »

A quick search of HROs web site shows the following:

Alinco DJ-175T
Icom IC-V80
Kenwood THK20A
Vertex-Standard VXD-720
Yaesu FT-270R

Sure, they're all 5W radios. But add a 1/2 wave whip antenna and you'll pick up 3dB over a 1/4 wave in the direction you're interested in (unless you're trying for an ISS contact). 3dB gain with a 5 Watt radio=10 Watts. Today's radios use NiMH and other battery chemistry that packs a lot more power into a small place, so small battery packs get about the same run time as the old NiCad packs.

And as others have pointed out, the FT-817 is actually very nice to use "hand held" with the shoulder strap.

Also, there's a ton of surplus commercial gear and "classic" HTs from the 1980s and 90s on the secondary market.
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VE5EIS
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« Reply #10 on: July 04, 2013, 01:40:06 PM »

For years, there have been 100 + watt VHF mobiles that have been used with the antennas within four feet of the users--and there hasn't been even one report of harm to those users from them.  Who?  Police officers and public service workers--people exposed every working day to the use of two way radios.

To be safe they should be under the antenna (which is located on the roof of their vehicle).  Having that high powered a transmission from a trunk or hood antenna really isn't all that safe for anyone in the vehicle during transmitting.
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KA5IWO
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« Reply #11 on: July 04, 2013, 03:21:35 PM »

K1CJS stated:
"There are some HTs that have a slightly greater output depending on the power fed into them.  For example, the Icon T7H that I use will output 7 to 8 watts of power if you use the car connector cord to feed it from the cigarette lighter/power socket of your vehicle, but it will fold back power after a minute or two because of the heat generated by the output stage. You would think a longer 1/4 wave antenna would stop that from happening, but it usually does not."

UHHHH, what??
How in the world is a longer 1/4 wave antenna going to ever stop any transmitter from folding back from thermal heat? If the radio has thermal protection for the output stage, it simply lower the output power to keep it from burning up. If you are using a correctly matched 1/4 wave antenna for the band your on, replacing it with a properly matched 5/8 wave antenna will give you more tx and rx gain but does nothing for your transmitters thermal protection circuit. It will get hot period if you tx / talk forever on any ht. Some do not have any protection for thermal, high swr, overvoltage, etc...
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KQ6Q
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« Reply #12 on: July 04, 2013, 07:27:53 PM »

SMAUG - Any HT running at 5W quickly gets to hot to hold in your hand. More RF radiation an inch or so from your face not healthy either.
Before you suggesting than manufacturers start building the last century"s HT's again, just buy an old Brick unit (Radio shack HTX-202 is a good example) and see how much you enjoy operating it compared to your newer, smaller radio.
If you can't hit a repeater with 5W from an HT, 10W won't do it either. Most repeaters are positioned so that you can hit them with your low power setting in metro area. Batteries last a lot longer on low power too!
If you want more range from your HT cheaply, invest in one of the antennas that's longer than the stock  'duck' that came with your radio. Then notice how much it gets in the way if you're carrying the radio around with you.
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K1CJS
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« Reply #13 on: July 05, 2013, 07:18:37 AM »

To be safe they should be under the antenna (which is located on the roof of their vehicle).  Having that high powered a transmission from a trunk or hood antenna really isn't all that safe for anyone in the vehicle during transmitting.

You're right--and you're wrong.  Most of the time during the heyday of the trunk mounted 'works in a drawer' radios, the antenna was put in the middle of the trunk lid--it was easier and better (for the working of the radio) to put it there.  It was only recently, with the advent of the 400mhz band that the antenna started to be put on the roof--and then it wasn't for the safety aspect, it was to provide more even transmission and reception coverage at those frequencies.  It was only during the last half dozen years or so that the so called 'safety aspect' of RF at those frequencies (the 'lawyer' mentality) that the antennas were always put on the roof of the vehicle.

VHF RF isn't harmful at usual power levels.  UHF RF may be, depending on the power levels.  XHF (gigahertz frequencies) could well be.  It's your right not to believe me, but ask those people who live within spittin' distance of 50,000 watt FM radio transmitters if they're bothered by the RF power from those transmitters.  Ninety-nine times out of a hundred, the people will tell you they're more bothered by the transmitter tower they see every day or the RFI generated into the cheap consumer electronic devices they may have!
« Last Edit: July 05, 2013, 07:42:21 AM by K1CJS » Logged
K1CJS
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« Reply #14 on: July 05, 2013, 07:39:36 AM »

UHHHH, what??
How in the world is a longer 1/4 wave antenna going to ever stop any transmitter from folding back from thermal heat? If the radio has thermal protection for the output stage, it simply lower the output power to keep it from burning up. If you are using a correctly matched 1/4 wave antenna for the band your on, replacing it with a properly matched 5/8 wave antenna will give you more tx and rx gain but does nothing for your transmitters thermal protection circuit. It will get hot period if you tx / talk forever on any ht. Some do not have any protection for thermal, high swr, overvoltage, etc...

I didn't say it would stop it.  I said you may think it would.  I also said the HT WILL fold back after a minute or two.  Providing a more efficient antenna for the HT to transmit with WILL lessen transmitter losses, however.  That is what I really meant.  It stands to reason that the more energy the antenna will radiate into space, the less will be wasted as heat.  No matter how you may figure, a six inch wire wound rubber duckie may be 19+ inches long electrically, but it isn't as efficient as an actual nineteen+ inch long whip.
« Last Edit: July 05, 2013, 07:44:33 AM by K1CJS » Logged
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