Power Pack for Amateur Radio Field Operation

Low Cost Emergency Power Pack for Field Deployment of Amateur Radio

by Dr. Carol F. Milazzo, KP4MD (posted 10 July 2014)
E-mail: kp4md@arrl.net

This Jump Start Power Pack is a low cost rechargeable emergency power option that can be easily adapted to power amateur radio operation in the field.  Conveniently rechargeable from 110 volt commercial power or a solar panel with regulator, the addition of Anderson PowerPole connectors enables the power pack to provide the voltage and current required by amateur radio transmitters in the 100 watt range.


Rechargeable Jump start purchased for $39 at
                      Harbor Freight.
http://www.harborfreight.com/12-volt-jump-start-and-power-supply-38391.html

1. Rechargeable Jump start purchased for $39 at Harbor Freight. http://www.harborfreight.com/12-volt-jump-start-and-power-supply-38391.html

The
                      Jumpstart's 12 volt sealed lead acid battery is
                      rated at 17 Ah.

2. The Jumpstart's 12 volt sealed lead acid battery is rated at 17 Ah.

Initially, I wired a pair of Anderson
                      PowerPole connectors to a cigarette lighter plug
                      for use as light duty emergency power pack for the
                      amateur radio station. This was sufficient only
                      for radios that draw two amperes or less.

3. Initially, I wired a pair of Anderson PowerPole connectors to a cigarette lighter plug for use as light duty emergency power pack for the amateur radio station. This was sufficient only for radios that draw two amperes or less.

The
                      measured voltage at the cigarette lighter socket
                      decreased proportionally to the current drawn.
                      Below 11.1 volts, the radio's frequency display
                      went dark and the cigarette lighter plug and
                      socket became hot. The calculated internal
                      resistance was 0.05 ohms for the battery and 0.1
                      ohms for the internal wiring, the cigarette
                      lighter socket and plug.

4. The measured voltage at the cigarette lighter socket decreased proportionally to the current drawn. Below 11.1 volts, the radio's frequency display went dark and the cigarette lighter plug and socket became hot. The calculated internal resistance was 0.05 ohms for the battery and 0.1 ohms for the internal wiring, the cigarette lighter socket and plug.

Anderson PowerPole connectors were installed
                      to permit operation of radio equipment that
                      requires more current. To wire PowerPole contacts
                      in tandem, cut and solder a tinned 12AWG solid
                      wire into a U shape with 5/16" spacing and
                      13/16" length.

5. Anderson PowerPole connectors were installed to permit operation of radio equipment that requires more current.  To wire PowerPole contacts in tandem, cut and solder a tinned 12AWG solid wire into a U shape with 5/16" spacing and 13/16" length.

A
                      length of 12AWG stranded wire is soldered to the
                      center of each U.

6. A length of 12AWG stranded wire is soldered to the center of each U.

The
                      PowerPole contacts are fully inserted into their
                      housings.

7. The PowerPole contacts are fully inserted into their housings.

The
                      assembled PowerPole connectors slide into the
                      1470G1 chassis mount and are secured with a 110G9
                      retaining roll pin.

8. The assembled PowerPole connectors slide into the 1470G1 chassis mount and are secured with a 110G9 retaining roll pin.

After
                      disconnecting and removing the battery, the holes
                      for the chassis mounts are drawn--each one 2.2 cm
                      by 3 cm. Two chassis mounts are required to
                      provide power connections for the radio, an
                      amplifier and an antenna tuning unit.

9. After disconnecting and removing the battery, the holes for the chassis mounts are drawn--each one 2.2 cm by 3 cm.  Two chassis mounts are required to provide power connections for the radio, an amplifier and an antenna tuning unit.

The
                      chassis mount holes are cut with a Dremel tool
                      cutting wheel.

10. The chassis mount holes are cut with a Dremel tool cutting wheel.

The
                      PowerPole chassis mounts are snapped into place.

11. The PowerPole connectors in their chassis mounts are snapped into place.

The
                      other end of each 12AWG stranded wire was soldered
                      to a ring terminal for attachment to its
                      respective battery terminal.

12. The other end of each 12AWG stranded wire was soldered to a ring terminal for attachment to its respective battery terminal.

I
                      soldered another pair of Anderson PowerPole
                      connectors onto a properly fused DC power cable
                      for my HF transceiver.

13. I soldered another pair of Anderson PowerPole connectors onto a properly fused DC power cable for my HF transceiver.

After
                      installing the Anderson PowerPole connectors on
                      the power pack, the transmitter produced the full
                      rated 100 watts RF output. The fully charged power
                      pack delivered 15.74 A at 11.74 V through the
                      Anderson PowerPole connectors with 11.8 V at the
                      battery terminals. The radio's display showed no
                      dimming or instability.

14. After installing the Anderson PowerPole connectors on the power pack, the transmitter produced the full rated 100 watts RF output. The fully charged power pack delivered 15.74 A at 11.74 V through the Anderson PowerPole connectors with 11.8 V at the battery terminals. The radio's display showed no dimming or instability.

This 13
                      watt briefcase solar charger with a solar charge
                      regulator maintains the 17 Ah battery sufficiently
                      charged for low power station operation through
                      daylight and night hours.

15. This 13 watt briefcase solar charger with a solar charge regulator maintains the 17 Ah battery sufficiently charged for low power station operation through daylight and night hours.
http://www.harborfreight.com/13-watt-briefcase-solar-charger-68750.html
http://www.harborfreight.com/7-amp-solar-charge-regulator-96728.html

LINK

  1. Battery Backup Power Pack Photo Album


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