144 MHz POWER AMPLIFIER BY 2 X GS35B

Sent by somebody to show his homebrew 2 m linier power amplifier using russian tubes 2 x GS35B

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2000 WATT 144 MHz POWER AMPLIFIER

Sent by somebody to show his homebrew 2 m linier power amplifier using russian tube 2 x GS31B

400 ~ 470 MHz ANTENNA TUNER

• Estimated cost : Rp 50.000 (USD 5)
• Condition : Homebrew, with all components available at locat market.

Personal review :

• Simple and easy to built.
• VSWR 1.0 ~ 1.5 with handling power up to 200 Watt.
• Low insertion loss 0.2 dB
• As a Low Pass Filter, thus reduce transmitter interference to adjacent TV channels.

1500 WATT, 430 ~ 450 MHz LINIER AMPLIFIER

• Estimated cost : Rp. 8.000.000 (USD 800)
• Condition : Homebrew

Personal review :

• Built from Rusian tube GS 31
• Power Input 10 ~ 50 Watt
• Power Output 1500 Watt maximum.
• Power output / emmision still good/stable after operated more than 500 hours.
• Easy to be modified to 800 MHz bandwith power output 800 Watt maximum.

50 ~ 950 MHz SPECTRUM ANALYZER

• Estimated cost : Rp. 300.000 (USD 30)
• Condition : Homebrew, with all components available at local market

Personal review :

• dual channels Osciloscope required.
• built from 2 pcs TV Tuners. (for spectrum analyzer and tracking generator respectively)
• Operating frequency : 40 ~ 100 MHz, 100 ~ 250 MHz, 400 ~ 950 MHz (depending TV tuner capabilities)
• Require more development to get better accuracy (additional band pass filter, etc)
• Simple and easy to build.
  

145 MHz / 435 MHz ANTENNA TUNER

• Estimated cost : Rp. 50.000 (USD 5)
• Condition : Homebrew with all components available on local market.

Personal review :

• Suitalbe for dual band transceiver.
• Adjustable frequency range 140 ~ 150 MHz, and 430 ~ 450 MHz
• Single input and single output with VSWR Input : 1.1 ~ 1.5 at 50 Ohm impedance.
• Power handling 50 Watt maximum, better capasitors will improve power handling
  

3 ~ 30 MHZ, 50 WATT POWER AMPLIFIER

• Estimated cost : Rp.200.000 (USD 20)
• Condition : Homebrew, with all components available at local market

Personal review :

• Broadband Linier RF amplifier from 3 ~ 30 MHz (FM, AM/SSB)
• Power input 50 mW ~ 1 Watt
• Power Output 50 Watt maximum at 12.5 VDC, 8 Amperes
• Power transistor 2 x 2SC1969
• very useful as portable booster for Remote control transmitter (below 40 MHz), 11m/27 MHz walkie talkie or Citizen Band, etc.
• Easy to build, no tune required, however additional filter might be required for permanent operation to avoid interference to TV.

DIAMOND X-200; 145 MHz/ 435 MHz DUAL BAND ANTENNA

• Estimated price : Rp. 650.000
• Condition : Original, 5 years old installed on the roof.

Personal review:

• High quality and high performance dual band antenna.
• after 5 years installed outdoor, no corrosion or defected indentified.
• with 2.5 m lenght, Gain VHF 6 dBi, UHF 8 dBi
• VSWR 1.0 on 145 MHz and 435 MHz.
• Low VSWR 1 ~ 1.5 on UHF 430 ~ 470 MHz
• VSWR 1 ~ 1.5 on VHF 144 ~ 148 MHz
• with 15 Watt transmitter output, can hit all repeaters at Jakarta from Bandung ( antenna installed 10 m from ground).
  
  

145 MHz / 440 MHz DUPLEXER

General :

• Estimated cost : Rp 100.000 (USD 10)
• Condition : Homebrew, with all components available on local market

Personal review :

• Simple but not easy to setup, especially on UHF (440 MHz) part.
• Operating frequency 144 ~ 148 MHz and 433 ~ 438 MHz
• VSWR 1.0 ~ 1.5
• Power handling 100 Watt maximum ( to get better power handling, the good quality variable capacitors are required).
• With this duplexer, we can equip dual band transceiver, with separate VHF and UHF power amplifiers, or separate VHF and UHF antennas, or combine VHF and UHF transmitter. etc.

60 WATT, 140 ~ 150 MHz BROADBAND AMPLIFIER

• Estimated cost : Rp. 600.000 (USD 60)
• Condition : Homebrew with all components available on local market.

Personal review :

• Wide operating frequency from 140 ~ 150 MHz,
• Power input 500 mW ~ 1 Watt.
• Power Ouput 60 Watt minimum at 12.5 VDC, 9 Amp.
• Good VSWR input : 1.1 ~ 1.5
• Power transistor 2SC1946 and 2SC2630
• Minimum adjustment required.
• 90 WATT maximum power output with 13.8 VDC supply - NOT RECOMMENDED !!!

DIGITAL VOLT / AMPERE METER

• Estimated cost : Rp. 100.000 (USD 10)
• Condition : Homebrew with all component available on local market.

Personal review :

• Simple and easy to build.
  

S METER / VU METER WITH LED

• Estimated cost : Rp. 20.000 (USD 2)
• Condition : homebrew, with all component available on local market.

Personal review :

• Simple and easy to build.
• utilise LM3914 or LM3915 or LM3916 (linier or logarithmic or dot/bar scale)
• single supply 3 ~ 12 VDC.

4 kW HF POWER AMPLIFIER - SOLID STATE

My colleague send this picture to show his project to develop 4.000 Watt HF power amplifier with 32 x MRF 454.



No comment !

HOMEBREW - 500 WATT 450 MHz POWER AMPLIFIER

• Expected price : Rp. 5.000.000 (USD 500)
• Condition : Homebrew, all components availble on local market

Personal review :

• Operating frequency 430 ~ 450 MHz, FM/SSB.
• Power input 5 ~ 50 Watt
• Power output 500 watt maximum at 13.8 VDC, 55 Ampere nominal.
• built from 10 x 2SC3012.

HOMEBREW - ANTENNA/SWR ANALYZER

• Expected price : Rp. 150.000 (USD 15)
• Condition : Homebrew with all component from local market.

Personal review :

• Operating range 0.5 ~ 30 MHz
• Sufficient accuracy with additional frequency counter.
• Useful instrument for antenna, filter, power amplifier experiments.

HOMEBREW - RF FIELD STRENGTH METER

• Expected price : Rp. 100.000 (USD 10)
• Condition : homebrew with components available in local market

Personal review :

• Operating range 500 kHz ~ 2.4 GHz (WiFi) depending external antenna attached.
• Very sensitive meter, thus can read power less than 50 mW within a few cm from antenna. (tested with ordinary WiFi router/access point).
• Useful instrument for experiment antenna or oscilator/transmitter trouble shooting .

DIAMOND SX-400, 140 ~ 520 MHz SWR METER

• Expected price : Rp. 650.000 (USD 65)
• Condition : 99% as new (collection only)
  

Personal review :

• Operating range 140 ~ 520 MHz, with 5W, 20, 200 Watt reading.
• Sensitive sensor/directional coupler, then it can read power below 100 mW.
• Peak hold feature for reading PEP power ( transmitter on SSB mode).
• back light on meter display (external 12 VDC required)
  

DAIWA CN-801H, 1.8 ~ 200 MHz SWR METER

General :

• Expected price : Rp. 1.000.000
• Condition : 99% as new (collection only)

Personal review :

• Operating range 1.8 ~ 200 MHz, with 20W, 200W, and 2 kW reading.
• Cross needle meter, reading both forward and reflected power.
• Peak hold feature to read PEP power (transmitter on SSB mode)
• Large meter with back lamp for reading on the dark condition.

ALINCO EP-3010, 30 AMPERE POWER SUPPLY

General :

• Expected price : Rp. 600.000 (USD 60)
• Condition : All components are original as per manufacture specification, plus additional capasitor bank to improve load regulation.
  

Personal review :

• Output voltage 8 ~ 15 VDC at 30 Ampere continuous, or 35 Ampere intermittent 1 min ON/OFF.
• Overload protection with current fold-back at 35 Ampere, 13.8 VDC
• This linear power supply suitable to supply power to power amplifier up to 250 Watt.

DIAMOND GSV-1200, 15 AMPERE POWER SUPPLY

General :

• Expected price : Rp. 800.000 (USD 80)
• Condition : 95% as new, all components are original as per manufacture specification.
  

Personal review :

• Adjustable Output 1 ~ 15 VDC, with 12 A continuous 8 Hours, or 15 A intermittent 1 min ON/OFF.
• Input 110 or 220 VAC
• Load regulation less than 2%
• Overload current fold-back at 17 A, 13.8 VDC
• Ripple voltage 3 mVpp at 12 A, 13.8 VDC
• Weight 5.8 kg
• This linear power supply (transformer based) having compact size, and suitable to provide power for modern transmitter, the ripple voltage is very small (3 mVpp) thus suitable to supply dc power to handy transceiver.
• Silent Power Supply since it was using large heat sink instead of electric fan.
  

SL-200S - 200 WATT HF POWER AMPLIFIER

• Expected price : Rp. 1.000.000 (USD 100)
• Condition : All components are original as per manufacture specification.

Personal review :

• Frequency range 3 ~ 30 MHz, AM/FM/SSB
• Power input 1 ~ 10 Watt
• Power output 200 Watt
• Band pass filter not included.
• HI and LO selection.
  

TONO MR-250W - 350 WATT 144 MHz VHF POWER AMPLIFIER

General :

• Expected price : Rp. 3.500.000
• Condition : Power transistor were replaced with 4 x 2SC2782, the other components are original as per manufacture specification.

Personal review :

• Frequency range 144 ~ 148 MHz, FM and SSB mode.
• Power input 5 ~ 50 Watt
• Power output 350 Watt with 50 Watt input at 13.8 VDC, 46 Ampere
• RX amplifier included
• Illuminated analog meter indicator for Operating Voltage, Power Output and SWR
  

RF CONCEPT RFC4-32, 20 WATT UHF POWER AMPLIFIER

General :

• Expected price : Rp. 800.000
• Condition : Power transistor is original, the RX amplifier transistor was replaced by equivalent and working properly.
  

Personal review :

• Wide band frequency range 100 ~ 520 MHz
• Power input 100 mW ~ 3 Watt
• Power output 20 Watt maximum
• Interesting is the amplifier is working between 100 ~ 520 MHz, but the optimal gain is achieved on UHF amateur band.
• Suitable for mini dual band transceivers such as VX-1R, VX-2R, VX-3R, IC-Q7, etc.
  

TOKYO HY-POWER HL-60U, 60 WATT 440 MHz UHF POWER AMPLIFIER

General :

• Expected price : Rp 900.000 (USD 90)
• Condition : 99% as new (collection only)
  

Personal review :

• Frequency range 430 ~ 450 MHz
• Power input 0.5 ~ 10 Watt
• Power output 60 Watt at 13.8 VDC, 9 Ampere nominal.
• RX amplifier included.
• Interesting circuit is using RF diodes to replace mechanical change over relay.
  

TOKYO HY-POWER HL-120U, 120 WATT UHF POWER AMPLIFIER

General :

• Expected price : Rp. 2.000.000 (USD 200)
• Condition : 99% as new (collection only)

Personal review:

• Frequency range 430 ~ 450 MHz, FM and SSB mode
• Power input 3 ~ 10 Watt
• Power output 120 Watt minimum at 13.8 VDC, 20 Ampere nominal
• HI/LO power selection, with power meter illuminated analog meter indicator.
• RX amplifier included.
• Original power transistors 2 x MRF648 and 1 x 2SC2381