This is part two of the repair video for the Yaesu FT-7800 dual band transceiver. For part one, see the link below this text. The faulty PIN diodes turned out to be discontinued. A viewer of the part 1 video suggested that the successor radio (FT-7900) is very similar and uses a different part number for these PIN diodes. Further investigation revealed that this part of the circuit design is essentially identical, so I ordered the diodes used in the 7900. This video shows the replacement process and bench check for 2 meter transmit operation. I deeply apologize for the lousy camera angle and video work at about the 9 minute mark.
Part 1:
http://www.youtube.com/watch?v=Cz_OcsqZXn4 />To learn more about PIN Diodes, see this tutorial video:
http://www.youtube.com/watch?v=XpYsCM_Wf50

Xiegu G106 HF Transceiver,SDR, 5W,SSB/CW/AM, WFM (88~108MHz) Reception,Support FT8.

$299.79 (as of December 9, 2023 05:26 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)

High Performance - The high performance SDR core circuitry is designed to be a QRP model with a compact, ruggedized design. This makes the G106 an excellent choice for 5W portable two-way radios. Multiple Frequency Bands - In addition to sending and ... read more

Xiegu GNR1 Digital Audio Noise Filter, Noise Reduction, 22DB, Knob Control

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$215.00 (as of December 9, 2023 04:42 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)

This radio filter supports to connect external passive speaker, which can provide 3W audio output power. You can enjoy the most origin and clear sound with this filter without losing any quality. Designed with big knobs at the front side, you can adj... read more

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$34.99 (as of December 9, 2023 04:47 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)

3W power, 4Ω impedance, and the 3.5mm stereo interface design, which makes GY03 support left and right channels, provide outstanding sound quality and loud enough volume for outdoor use. The 10-feet power cable is long enough to place this external s... read more

Xiegu X6100 HF Transceiver,SDR,10W,Full Mode,Built-in Battery,Portable Long Range Two-Way Radio

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$579.00 (as of December 9, 2023 04:42 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)

Full Mode-HF/50MHz Full Mode (supports data communications), High performance SDR platform for both daily/competition for your long range transmission needs. Desktop-rivaling features such as recorded calls, variable bandwidth digital filters, digita... read more

Xiegu G90 HF Radio 20W SSB/CW/AM/FM SDR Structure with Built-in Auto Antenna Tuner

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$499.00 (as of December 9, 2023 06:19 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)

Detachable Display Unit - The display unit and the radio body can be separated. This allows you to place the head remotely. Wide Range Auto Antenna Tuner - Unlike other QRP radios, the G90 has a wide-range internal automatic antenna tuner so you can ... read more

GOODYEAR - [4 GAUGE, 16 FT] - TRANSFERS HIGHER VOLTAGE THAN 6, 8, 10 or 12 GAUGE] Heavy Duty Jumper Cables with PVC CASE, Emergency Roadside Assistance, Works in EVERY WEATHER

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$24.99 (as of December 9, 2023 08:21 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)

HEAVY-DUTY CAR JUMPER CABLES - These booster cables from Goodyear are made with material that can take constant wear and tear. You can use them time and time again without worrying that they’ll let you down, and you can bend and twist these wires at ... read more

ONGTEED Portable AM FM Analog Radio, Bluetooth Speak Vintage Transistor Radio, Support USB TF Card, Built-in Rechargeable Battery, 2xD Cell Battery Operated or AC Power Plug in Wall with Loud Speaker

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$25.99 (as of December 9, 2023 08:10 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)

【3 Types of Power Source】 While you are indoors, the AC-110V-50Hz power allows you to plug the charging cable (included) into the wall to listen to radio the whole day. The built-in 1200 mAh rechargeable battery is the perfect choice when you want to... read more

42V 2A Charger 5 Plugs Universal for 36V Lithium Battery, Pack DC 5.5 * 2.1 with 8mm 3 Prong Connector /12mm 3 Prong Connector /8mm RCA Connector/ 3-Pin Male XLR Connector

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$16.95 (as of December 9, 2023 02:51 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)

5 connectors in 1: The charger come with 5.5mm 1-prong DC plug,8mm 3 Prong Connector, 12mm 3 Prong Connector, 8mm RCA and 3-Pin Male XLR Connector. Fast and Smart: Fast charge with high current. Green light means full charged or disconnected. Don't u... read more

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LONG RANGE TRANSMISSION AND CRYSTL CLEAR SOUND — With upgraded custom helix gain antenna, super penetration, and lossless transmission technology. You can speak clearly and your kids can hear clearly within 1 mile in the yard or indoors. Longer range... read more

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$21.99 (as of December 9, 2023 08:10 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)

【Awesome Multifunction】Emergency weather radio with an ultra-bright LED flashlight and retractable 180° rotating reading lamp keeps you out of the dark during emergency power outages or at night. Loud SOS alarm and eye-catching flashing light to call... read more

Retekess TR604 AM FM Radio, Battery Operated Radio Portable, AM FM Radio Plug in Wall, High/Low Tone Mode, Big Speaker, Earphone Jack,for Senior, Home

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10% Off $29.99 $26.99 (as of December 9, 2023 08:21 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)

Simple operation, easy to use; provide simple operation for the elderly who do not know how to set the numbers, large knob and analog readout make frequency and volume adjustment easy to operate, the elderly or people with poor eyesight can easily li... read more

Retevis RT22 Walkie Talkies Rechargeable Hands Free 2 Way Radios Two-Way Radio(6 Pack) with 6 Way Multi Gang Charger

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$129.99 (as of December 9, 2023 00:11 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)

The FRS two way radio is extremely compact and slim for business use; featured with 16 channels and rich features; license free; you don't need a license for RT22 walkie talkie 0-9 level voice activated transmit function allows real hands free operat... read more

10000mAh Emergency Hand Crank Radio,AM FM NOAA Weather Alert Radio, Digital Display,3 Ways Powered Hand Crank,Solar Radio with Type-C Charger,Flashlight,Reading Lamp,Headphone Jack,SOS Alarm (Black)

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Automatic Alert Radio-The radio emergncy clock alarm solar has alarm function.The function may save your life!The auto-scans for emergency and weather alerts when the power is on,long press the BAND button to active the alarm function.The hand crank ... read more