yes, that was my point...100 is most likely too much to expect, but 50
should be doable for short periods at any rate.
73
Colin, V A6BKX
----- Original Message -----
From: "John Miller" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Friday, August 05, 2005 7:57 AM
Subject: Re: battery packs


> They don't make 2 hours on 100 watts though back it down to 30 or 50 and
> they do alright on SSB.
> ----- Original Message -----
> From: "Colin McDonald" <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Friday, August 05, 2005 9:44 AM
> Subject: Re: battery packs
>
>
> good points...however, i have seen those portable charging units that
claim
> about 7 amp hours plus about 1500 cold cranking amps to be able to jump
> start a vehicle....these type of packs should provide enough current to
> operate at a relatively heavy current draw for several hours given the
> intermittent nature of SSB operation...if FM was going to be operated then
i
> think one of those packs would certainly go dead quickly but SSB only
draws
> that current when modulating and one is only really modulating for brief
> periods of time throughout that one  hour.  Its not like you will be rag
> chewing when you are trying to make contacts...lets say maximum 15 seconds
> of modulation at 12 amps or so with 50 watts.
> You take that and you times that 15 seconds over and over until you get
> about 35 minutes, using the 7 amp hour pack and you are looking at an
aweful
> lot of contacts and several hours.
> I dont know how to actually calculate that, but the math is sound and you
> can figure out the number of hours you could get out of a relatively low
> current supply, assuming it will provide the higher current for short
> periods of time...which most of these portable packs will do.
>
> These portable packs are smaller then a regular sized car battery and much
> lighter...easy enough to attach to a back pack or be even hand carried if
> necessary.
> I still want that website that gives all this info regarding battery
> packs...allot of this idea of using lesser current supplies and figuring
out
> how long you can run a higher current draw on SSB is all on this website.
>
> 73
> Colin, V A6BKX
> ----- Original Message -----
> From: <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Friday, August 05, 2005 1:26 PM
> Subject: Re: battery packs
>
>
> > Message-Id:
> <20050805132709.LBGM3503.ibm70aec.bellsouth.net@[68.212.116.131]>
> >
> > Fred wrote,
> >    >Well, if you're going to use battery power, you'd better think of
> >    >qrp, 50 to 100 watts will drain them in a hurry, or you'd better
> >    >take the world's longest extension chord for the charger.
> > Even then, better be two stout dudes if you're gonna pack enough
> > battery power to do this.  gel cell packs that would handle that kind
> > of power and give you a few hours of operation are quite heavy.
> > Definitely be thinking qrp in this application.
> > I had a bunch of those 7 amp/hour gel clels that came from burglary
> > and fire alarm systems and they can be heavy even.  Up at Charity
> > Hospital here in NEw oRleans we've got a couple of 100 amp/hour
> > batteries and they're heavy dudes.  I brought them up there on a two
> > wheeled handtruck.  NOt something I'd want to be packing up a mountain
> > along with food tents etc.
> > THough everything else in our hobby has miniaturized except antennas
> > batteries haven't downsized that much. AS one fellow said, when they
> > get there we'll actually see efficient electric vehicles.
> > wEre I going on such an expedition I'd consider qrp cw.  YEs Virginia,
> > leave the laptop at home too.
> > Speaking of such activities I'd probably use the National RAdio
> > emergency net as a point of contact with the outside world.  These
> > folks use the guard frequencies 7068 10122 and 14050 khz.  tHey're
> > there for just this purpose.
> >
> >
> >
> >
> > Richard Webb
> >
> > Electric Spider Productions
> >                                             "They that can give up
> essential liberty to obtain a little temporary
> > safety deserve neither liberty nor safety."
> > --- Benjamin Franklin, NOvember 1755 from the
> > Historical review of Pennsylvania
> >
>