[VHFcontesting] The digital modes and the Sept contest

[Mark Spencer]

My approach to figure out if:

-Could I run my radios and amps from typical battery voltages ?

-Roughly how long would the batteries run the station ?

I ran my gear from a variable 70 amp power supply and assessed the performance at various voltage levels.   During this process I also concluded that I wasn't going to get 375 watts from my amp that is nominally rated at 375 watts.  (Presumably due to the batteries providing somewhat less than 13.8 volts.)   I'm happy with 300 watts.   I seem to recall the battery vendor also had performance data for the batteries that gave the nominal capacities vs discharge rates along with terminal voltages vs capacity.

As a general rule I plan on using approx half of the rated capacity of my batteries before recharging them. 

I hope this is of some interest.

I realize the opinions and experiences of others may be different than mine.

73
Mark S
VE7AFZ


mark at alignedsolutions.com
604 762 4099

> On Sep 13, 2017, at 4:28 PM, Barry Hansen <barry at k7bwh.com> wrote:
> 
> Interesting battery discussion. Also interesting that the IC-910 seems to
> take significant d.c. power.
> I've recently acquired an Icom IC-9100 and I'm trying to choose the 13.8v
> portable power source. Last weekend in the Sept VHF contest the rig was
> set up for the first time with my SUV, and I discovered that my usual
> single automotive (Sears Diehard) sealed lead-acid battery is
> insufficient. This battery has worked well with an FT-897 and an IC-7100,
> but the larger power drain of the IC-9100 causes the rig to reset itself
> on xmit.
> Is there a way to calculate how long two car batteries in parallel would
> last?
> I already have a small Honda generator although I don't usually bring it
> along unless I'm using an amp. 
> Thanks in advance, 
> Barry K7BWH 
> Seattle CN87us
> 
> -----Original Message-----
> From: VHFcontesting [mailto:vhfcontesting-bounces at contesting.com] On
> Behalf Of Alan Larson
> Sent: Wednesday, September 13, 2017 3:42 PM
> To: vhfcontesting at contesting.com
> Subject: Re: [VHFcontesting] The digital modes and the Sept contest
> 
>> Hi Alan.  That is useful info re the ic910.  I'm just curious what 
>> type of batteries are you using.
>> 
>> I've had considerable success running my ic7300, FT736, multiple 
>> Icom706MkiiG's, an icom 735 IF radio, 300 watt amps on 50 and 144 MHz, 
>> transverter, etc..  from two 12 V 100 AH Agm style batteries.
> 
>  Over the years it has varied, but typically I would have 25 - 30 amp
> hours of sealed lead-acid batteries in parallel with the starting battery
> of the diesel VW.  Solar would be attempting to hold that up.
> 
>> I took another 100 AH battery with a solar panel with me during the 
>> June contest and used it to run an inverter that in turn powered the 
>> battery chargers for the computers and also powered another charger to 
>> top off the two radio batteries.  I had ample power for approx 6 to 8 
>> hours of operation including some MSK144 at close to full power on 50
> MHz.
> 
>  When operating from a small motor home, I have used 200 AH of battery
> feeding an inverter feeding a switching power supply to run the rig.  In
> the more space limited Volkswagen, a small Honda generator has proven to
> be the most convenient option.  (This includes consideration of the
> difficulty of getting all the items inside the Jetta.)
> 
>  For low power operation, I would still choose solar if available, but I
> wanted full power from the rigs.
> 
>        Alan
> _______________________________________________
> VHFcontesting mailing list
> VHFcontesting at contesting.com
> http://lists.contesting.com/mailman/listinfo/vhfcontesting
> 
> _______________________________________________
> VHFcontesting mailing list
> VHFcontesting at contesting.com
> http://lists.contesting.com/mailman/listinfo/vhfcontesting
>