Author Topic: Considering 900 mhz Handhelds for Close-Range Comms But Need AA Battery Options  (Read 614 times)

Offline The Professor

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Long story short(er):

The wife and I are considering new handhelds for multiple uses.  We're basically wanting radios that are much more simple to use than our Amateur handhelds.  We'd primarily use them for indoor and outdoor business comms at events but, being who and how I am, I want them to be usable in other ways, as well.

I've been looking at a couple of options, one of which is the Motorola DTR550 or DTR650 radio series.  They claim milspec 810 C, D, E & F specs, FHSS, , cloning, SMS Texting,  PC programmable and cloning.  I like most of what I'm hearing, but. . .one thing bothers me is that I can't find an AA-battery adapter for them.  This is something that may be a deal-breaker because we sometimes go to events where we camp for extended periods of time under what some would consider primitive conditions.

Rather than buy a dozen or two Lithium-Ion clip on batteries or try to rely upon a generator or solar set-up to recharge, I'd rather have the option to bring along a bunch of AA batteries  or buy them on-site.

Unfortunately, I cannot seem to locate any clip-on adapters, so my question is: how difficult would it be to make a working AA battery adapter?

Thoughts?

The Professor

Offline Greekman

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very difficult IMHO.
you need 6 batteries to get the right voltage (assuming the radio are 7.2V lithium) and even 6 AAA will not fit in the space of a usual flat lithium battery.

and do not forget, I have not met a radio that DOES NOT power down to 2 watts when used with Alkalines.


Offline The Professor

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very difficult IMHO.
you need 6 batteries to get the right voltage (assuming the radio are 7.2V lithium) and even 6 AAA will not fit in the space of a usual flat lithium battery.

and do not forget, I have not met a radio that DOES NOT power down to 2 watts when used with Alkalines.

What about an external power pack with Lithium AA's?  Size wouldn't matter, but I wouldn't be sure how to "mate" it with the radio body.

The Professor

Offline Greekman

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they have an odd voltage of 1.7-1.8V, that is hard to combine and make 7.2V (8.4V actual)
my kenwood handheld can work on 4 of them, yet still down powers to 2.2Watt

Offline kid_couteau

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Could you use more AAs for a higher voltage and hook it to a buck-boost converter to tune it down to the needed voltage?

Offline Greekman

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6 NiMh AA replace 2 lion (7.2V)...
with a DCDC converter anything is possible....
I have already done it for my kenwood where 4 li-ions are too many and 3 too little. But you risk the danger of noise.
if one is to go that route I think a constant current DC DC converter is the better option.

BTW I doubt the practicality of having to hold a separate battery carrier on the hand along with the HT. unless you have  3 feet of power cord and the battery carrier in the pocket
Then comes the question of where and how connecting the leads on the HT

I have done the alkaline mod
(see the adapter in this blogpost of mine http://greekpreparedness.blogspot.com/2013/05/diy-handheld-radio-external-battery-pack.html)
 and moved away from it to a li-ion/converter
http://greekpreparedness.blogspot.com/2015/10/my-ht-powerbank-generation-2.html

I would suggest the FT-60 that has an AA carrier as an accessory or any Chinese that offers a 6AAA or 6AA battery carrier. Some DMRs may even do.

I would laso suggest reading all the related articles in my blog. It is all about alternate power for radios from a preppers perspective

Offline SCWolverine

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some other considerations would be a MURS only rig (BTech does one on the 82 chassis that offers different battery options). or the Wouxun 2m/6m Hand that offers a AA tray as well.  maybe the Alinco tri-band handi that works with AA's and xmits on 1200MHz? lastly no known AA option, but this cheap Radioddity GD-77S DMR could be set up for simplex with tones on both sides and it'd be tough for anyone else to listen to what you're saying.