Repair And Restore A Boonton Radio Co. (Hewlett Packard) 230A RF Power Amplifier

[@jeremynichols4927]

I enjoyed seeing the 230A for historical reasons, as I have the very similar but somewhat newer 230B.

[@EriksElectronicsWorkbench]

Thanks for watching! Glad you enjoyed the video.

[@jeremynichols4927]

@@EriksElectronicsWorkbench operationally, the 230A and 230B are virtually identical. Looks like HP used the 230A design, changing only the name-plate. The 230B uses solid-state parts in a few locations but even the power supply design was unchanged except for solid-state diodes in place of the vacuum tube rectifier.

[@EriksElectronicsWorkbench]

@@jeremynichols4927 always interesting to see how designs are changed (or not) over time.

[@jeremynichols4927]

@@EriksElectronicsWorkbench I’m still researching this one. Have to hunt on line for Boonton catalogs to see when it was introduced; I have a good collection of HP catalogs but no Boonton (I suspect early 1950s). HP bought Boonton in 1959 but didn’t list their products until their 1963 catalog, with a special “Boonton” section in the front of the catalog. Hmmm, is that right? (Working from memory.) Anyway, the revised 230B was in HP catalogs from 1972 until 1976. Knowing HP, I suspect the 230B might have been available as early as 1970-71 (there was no full HP catalog for 1971) and probably would have been available on special order after 1976 until Boonton ran out of parts. Differences 230A vacuum tube rectifier 230B full-wave bridge (4 silicon diodes) also means a different transformer. 230A All components on metal chassis 230B PC board on chassis for power supply and meter circuitry. The B+ regulator circuit used the same tubes as did the 230A! HP used that same circuit in many instruments of that era. The meter circuitry was changed to solid state instead of the tube design in the 230A. The amplifier chassis uses the same tubes (2C39A) and may be identical-I haven’t seen a 230A schematic. Interesting that HP used the Boonton chassis design pretty much unchanged (except for the PC board) and didn’t force-fit the design into the Type-1 chassis that HP instruments were adapting.

[@EriksElectronicsWorkbench]

@@jeremynichols4927 yes the dates you mention seem correct. I have a technical data sheet for the 230A by HP dated 1967. The Boonton catalog mentions Boonton is a subsidiary of HP since 1959 and a divisional since 1962. I'm not sure when the 230A was first released. At 16:00 I show the schematic for the 230A. I don't have a 230B schematic.