Additions:
Deletions:
Additions:
Additions:
Additions:
The idea here is to pack a small AC to DC supply into
one side of the FT897 Battery Compartment inspired by the
Gamma Research HPS-1A∞. The Gamma Research itself won't quite fit into the 897, but the equivalent can be built within the space constraints. The other side of the FT897 Battery compartment would still be available for a battery, so you can have AC and battery ops internally. This is much smaller than the Yaesu internal supply,
which adds 1/2" to the radio height when installed.
This design adds
no height, fitting entirely inside the existing battery space.
The Gamma Research is rated at 5A continuous or 22A at 1/4 duty cycle. It consists of a 13.5V dc 5A switcher power supply feeding a 5F capacitor across the output. The capacitor takes up the current peaks in SSB and CW modes. In continuous modes like PSK31, AM, FM, RTTY the power must be lowered to about 30 watts out, in SSB mode the full 100 watts peak output can be reached.
Deletions:
The idea here is to pack a small AC to DC supply into
one side of the FT897 Battery Compartment inspired by the
Gamma Research HPS-1A∞. The Gamma Research itself won't quite fit into the 897, but the equivalent can be built within the space constraints. The other side of the FT897 Battery compartment would still be available for a battery, so you can have AC and battery ops internally. This is much smaller than the Yaesu internal supply,
which adds 1/2" to the radio height when installed. This design adds no height, fitting entirely inside the existing battery space.
The Gamma Research is rated at 5A continuous 22A at 1/4 duty cycle. It consists of a 13.5V dc 5A switcher power supply feeding a 5F capacitor across the output. The capacitor takes up the current peaks in SSB and CW modes. In continuous modes like PSK31, AM, FM, RTTY the power must be lowered to about 30 watts out, in SSB mode the full 100 watts peak output can be reached.
Additions:
The idea here is to pack a small AC to DC supply into
one side of the FT897 Battery Compartment inspired by the
Gamma Research HPS-1A∞. The Gamma Research itself won't quite fit into the 897, but the equivalent can be built within the space constraints. The other side of the FT897 Battery compartment would still be available for a battery, so you can have AC and battery ops internally. This is much smaller than the Yaesu internal supply,
which adds 1/2" to the radio height when installed. This design adds no height, fitting entirely inside the existing battery space.
Deletions:
The idea here is to pack a small AC to DC supply into
one side of the FT897 Battery Compartment inspired by the
Gamma Research HPS-1A∞. The Gamma Research itself won't quite fit into the 897, but the equivalent can be built within the space constraints. The other side of the FT897 Battery compartment would still be available for a battery, so you can have AC and battery ops internally. This is much smaller than the Yaesu internal supply,
which adds 1/2" to the radio height when installed.
Additions:
FT 897 Small Internal DC Supply
The idea here is to pack a small AC to DC supply into
one side of the FT897 Battery Compartment inspired by the
Gamma Research HPS-1A∞. The Gamma Research itself won't quite fit into the 897, but the equivalent can be built within the space constraints. The other side of the FT897 Battery compartment would still be available for a battery, so you can have AC and battery ops internally. This is much smaller than the Yaesu internal supply,
which adds 1/2" to the radio height when installed.
- 60W+ 12 or 15V switcher, readjust to 13.5V
- Voltage Equalizing resistors are required across each of the series capacitors to maintain voltage balance and protect the capacitors from the overvoltage that could otherwise result
Deletions:
FT 897 DC Supply
The idea here is to pack a small AC to DC supply into one side of the FT897 Battery Compartment inspired by the
Gamma Research HPS-1A∞. The Gamma Research itself won't quite fit into the 897, but the equivalent can be built within the space constraints.
- 60W 12 or 15V switcher, readjust to 13.5V
Additions:
Deletions:
Additions:
Size of the Yaesu FT897 Battery Compartment
- (need to find my notes or remeasure, but the important detail is 1+1/8" height available, the other dimensions are both about 7" as I recall)
Deletions:
Size of the Yaesu FT897 Battery Compartment
(need to find my notes or remeasure, but the important detail is 1+1/8" height available, the other dimensions are both about 7" as I recall)
Additions:
- 60W 12 or 15V switcher, readjust to 13.5V
- 3x5 inch footprint, must be less than 1+1/8" tall to fit
- Condor switcher 3x5x1" 12V or 15V 65W Supplies∞
- 25F 2.7V NessCap, 5 each in series, with balancing resistors produces a 5F capacitance
- Digikey Catalog Page∞
- reported from one source as 51 ohms 2 watt in the Gamma Research supply. Don't know if this is correct. Some research here to determine the proper value.
Deletions:
60W 12 or 15V switcher, readjust to 13.5V
3x5 inch footprint, must be less than 1+1/8" tall to fit
Condor switcher 3x5x1" 12V or 15V 65W Supplies∞
25F 2.7V NessCap, 5 each in series, with balancing resistors produces a 5F capacitance
Digikey Catalog Page∞
reported from one source as 51 ohms 2 watt in the Gamma Research supply. Don't know if this is correct. Some research here to determine the proper value.
Additions:
The idea here is to pack a small AC to DC supply into one side of the FT897 Battery Compartment inspired by the
Gamma Research HPS-1A∞. The Gamma Research itself won't quite fit into the 897, but the equivalent can be built within the space constraints.
The Gamma Research is rated at 5A continuous 22A at 1/4 duty cycle. It consists of a 13.5V dc 5A switcher power supply feeding a 5F capacitor across the output. The capacitor takes up the current peaks in SSB and CW modes. In continuous modes like PSK31, AM, FM, RTTY the power must be lowered to about 30 watts out, in SSB mode the full 100 watts peak output can be reached.
(need to find my notes or remeasure, but the important detail is 1+1/8" height available, the other dimensions are both about 7" as I recall)
Supplies
Condor switcher 3x5x1" 12V or 15V 65W Supplies∞
Capacitors
25F 2.7V NessCap, 5 each in series, with balancing resistors produces a 5F capacitance
Digikey Catalog Page∞
Equalizing Resistors
Deletions:
The idea here is to pack a small AC to DC supply into one side of the FT897 Battery Compartment inspired by the Gamma Research HPS-1A. The Gamma Research won't quite fit, but the equivalent can be built within the space constraints.
(need to find my notes or remeasure, but the important detail is 1+1/8" height available)
Supplies
Capacitors
25F 2.7V
NessCap
Digikey
http://dkc3.digikey.com/PDF/T062/1089.pdf∞
Equalizing Resistors
Additions:
Additions:
Deletions:
25F 2.7V
Digikey
FT 897 DC Supply
The idea here is to pack a small AC to DC supply into one side of the FT897 Battery Compartment inspired by the Gamma Research HPS-1A. The Gamma Research won't quite fit, but the equivalent can be built within the space constraints.
Note that I have not done this yet, there is a little engineering to be done.
Size of the Yaesu FT897 Battery Compartment
(need to find my notes or remeasure, but the important detail is 1+1/8" height available)
Supplies
60W 12 or 15V switcher, readjust to 13.5V
3x5 inch footprint, must be less than 1+1/8" tall to fit
Capacitors
25F 2.7V
Digikey
Equalizing Resistors
reported from one source as 51 ohms 2 watt in the Gamma Research supply. Don't know if this is correct. Some research here to determine the proper value.