03 February 2022

QRP Presentation Powering Radios Outdoors

  • Hand held this is the FT70D about 2 hrs or so on full 5w power with supplied battery depending on transmit time can be used from cigar lighter plug in car and to a whip on mag mount with suitable adapters
  • Yaesu FT817/818 shack in the box QRP rig draws 2.4 Amps on 6w transmit 300-400 Mili amps on receive
  • Power pole adapter, Peg legs speech compressor, and other accessories available for this rig at Sotabeams
  • Battery tray fits inside rig for eight AA alkaline waste of time and money half hour operation if your lucky
  • Supplied internal battery Ni-MH 1.9 Ah is better
  • Pros  light weight fits inside rig no power leads to worry about charges inside the radio
  • Cons limited life 1-1.5 hrs operation at best at 2.5w transmit power much less at full power 10 hrs to charge only 300-400 charge cycles  Old technology
  • Expensive to buy separately 40-50 quid at Martin Lynch can be sourced on E-bay slightly cheaper

Better power options

  • Cigar lighter lead for the car
  • Pros operate almost unlimited time
  • Cons Restricted to use in the vehicle using mag mount and whip antennas
  • Sealed lead acid battery this model designed to operate motorised telescopes 7Ah cost 60-70 quid
  • Pros good operation time 3-4hrs at full power this model has cigar lighter sockets USB sockets and a flashlight
  • Cons Heavy old technology 24 hr charge time approx 300 charge cycles has to be fully charged regularly at least every couple of months will not hold full charge if allowed to fully discharge
  • LifePo4 Lithium Iron Phosphate arguably one of the better options this model 8Ah about 45-50 quid
  • Pros good operation time this model 3.5-4hrs plus on full 6 watts power depending on transmit time
  • Lighter weight and size one third the weight of sealed lead acid equivalent
  • Newer technology more than 10 year lifespan with over 3000 charge cycles
  • Lots of different capacities available from as little as 1Ah up to more than 100Ah obviously higher capacities are larger, heavier and very expensive I find this model ideal for capacity vs size, weight and cost
  • Shorter charge times about 2-3 hrs for this model also unlike sealed lead acid if not used it only loses about  2% of its charge per month a full charge every six months is all it needs unlike sealed lead acid battery it is not as prone to degrade if allowed to fully discharge but don’t leave it fully discharged for long periods
  • LifePo4 batteries can be charged easily from a solar panel charger in the field if you want to go down that route at additional expense
  • Cons larger capacities can be very expensive
  • Needs a power lead made up to suit your particular radio I find power pole connectors are great for this type of work
  • Needs a dedicated charger for the LifePo4 technology at extra cost although I have seen some batteries that come with a charger source the web for your specific needs this model  just over 30 quid

These are just some ideas for you to think about for your QRP operations there are a lot more options available I have tried to show some options I have used that have worked for me  Keith M0JYP