Plan Execution: Difference between revisions
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Work began on February 10, 2020. |
Work began on February 10, 2020. |
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A working diary was maintained throughout the rebuild. This serves as a visual confirmation that something was done as opposed to using ones memory. Additionally it is a convenient place to store photos, schematics and other notes pertaining to the build. Most importantly is is a place to create "Things to remember to do". Such as "retightening ALL HV connections before turning power on. There were times during the rebuild where it was necessary to disconnect something in the HV circuit. I didn't want to forget to reconnect and tighten, so a deliberate note was made on the "Things to re..." page. |
A working diary was maintained throughout the rebuild. This serves as a visual and written confirmation that something was done as opposed to using ones memory. Additionally it is a convenient place to store photos, schematics and other notes pertaining to the build. Most importantly is is a place to create "Things to remember to do". Such as "retightening ALL HV connections before turning power on". There were times during the rebuild where it was necessary to disconnect something in the HV circuit. I didn't want to forget to reconnect and tighten, so a deliberate note was made on the "Things to re..." page. |
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Another valuable "checklist" was a copy of the complete schematic. As each component of the amplifier was checked for conformance with the Collins specification, and if found to be out of tolerance |
Another valuable "checklist" item was a copy of the complete schematic. As each component of the amplifier was checked for conformance with the Collins specification, and if found to be out of tolerance, was replaced. I used a tighter tolerance than Collins specified. For example if the specification for a resistor was 10%, I made sure it was 5% or better. Each component on the schematic was color coded. GREEN for checked and OK as is, YELLOW denoted that Bob have replaced the component and was validate as OK and BLUE denoted that it was replaced by myself because it was out of specification, looked compromised or just wasn't shiny enough.. |
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All told there were 58 components replaced by |
All told there were 58 components replaced by myself and 8 replaced by Bob. |
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Bob had actually replaced more than 8 components. Some electrolytics he had replaced were possibly 18 years old. Although may have never seen voltage, I automatically assumed that they need replacement. It's my philosophy towards electrolytics. If they are older than 10 years old. Replace them. The cheap no-name electrolytics you find on eBay come from less than reputable sources and are not of the quality of Vishay or Phillips. So if in doubt, replace. |
Bob had actually replaced more than 8 components. Some electrolytics he had replaced were possibly 18 years old. Although they may have never seen voltage, I automatically assumed that they need replacement. It's my philosophy towards electrolytics. If they are older than 10 years old. Replace them. The cheap no-name electrolytics you find on eBay come from less than reputable sources and are not of the quality of Vishay or Phillips. So if in doubt, replace. |
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Each sub-system was individually validated. For example. The 180 second cathode warm-up interlock circuit was validated by disconnecting the +12 VDC source with a fused +12VDC power supply and powered up. If the circuit did not energize the required relay, well, there was more trouble shooting to do. The HV supply, the bias supply, the screen voltage supply, the antenna changeover circuitry, the metering circuitry, etc were all independently validated. This made trouble shooting integrated system trouble shooting easier knowing where the fault was NOT located. |
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Revision as of 18:39, 23 May 2020
Work began on February 10, 2020.
A working diary was maintained throughout the rebuild. This serves as a visual and written confirmation that something was done as opposed to using ones memory. Additionally it is a convenient place to store photos, schematics and other notes pertaining to the build. Most importantly is is a place to create "Things to remember to do". Such as "retightening ALL HV connections before turning power on". There were times during the rebuild where it was necessary to disconnect something in the HV circuit. I didn't want to forget to reconnect and tighten, so a deliberate note was made on the "Things to re..." page.
Another valuable "checklist" item was a copy of the complete schematic. As each component of the amplifier was checked for conformance with the Collins specification, and if found to be out of tolerance, was replaced. I used a tighter tolerance than Collins specified. For example if the specification for a resistor was 10%, I made sure it was 5% or better. Each component on the schematic was color coded. GREEN for checked and OK as is, YELLOW denoted that Bob have replaced the component and was validate as OK and BLUE denoted that it was replaced by myself because it was out of specification, looked compromised or just wasn't shiny enough..
All told there were 58 components replaced by myself and 8 replaced by Bob. Bob had actually replaced more than 8 components. Some electrolytics he had replaced were possibly 18 years old. Although they may have never seen voltage, I automatically assumed that they need replacement. It's my philosophy towards electrolytics. If they are older than 10 years old. Replace them. The cheap no-name electrolytics you find on eBay come from less than reputable sources and are not of the quality of Vishay or Phillips. So if in doubt, replace.
Each sub-system was individually validated. For example. The 180 second cathode warm-up interlock circuit was validated by disconnecting the +12 VDC source with a fused +12VDC power supply and powered up. If the circuit did not energize the required relay, well, there was more trouble shooting to do. The HV supply, the bias supply, the screen voltage supply, the antenna changeover circuitry, the metering circuitry, etc were all independently validated. This made trouble shooting integrated system trouble shooting easier knowing where the fault was NOT located.