-------------------------------------------------------------------------------------------------------------------- May 16, 1980 HM-2140 Bulletin No: HF Dual Wattmeter HM-2140-1 Inoperative ++++Information not available at this time++++ -------------------------------------------------------------------------------------------------------------------- August 13, 1980 HM-2140 Bulletin No: HF Dual Wattmeter HM-2140-2 Battery Meter Pegs And Unit Will Not Null ++++Information not available at this time++++ -------------------------------------------------------------------------------------------------------------------- January 27, 1984 HM-2140 Bulletin No: HF Dual Wattmeter HM-2140-3 PEP Readings Inaccurate Make the following changes to the remote sensor and main unit. Recheck the calibration after installing these changes. New production will have these changes included. Remote Sensor [PN 100-1749]: Change C106 and C107 to .0027 uF [PN 27-141]. Do not disturb any control settings after making the change. Be sure to reseal the sensor using a service sticker. Main Unit: Change: C17 to .022 uF [PN 27-128] C18 to .033 uF [PN 27-138] Note: The only accurate method of checking PEP calibration is by using a two-tone test generator. The FCC standard tones for the two tone test are 400 Hz and 1800 Hz. A whistle represents only one tone and will give the same output as a steady carrier [CW] signal. Voice modulation may give a slightly different reading since the voice is composed of many tones. The PEP readings should be very close if the AVERAGE power readings are close. [PEP does not have an accuracy specification.] --------------------------------------------------------------------------------------------------------------------Thats everything I hold up to 1987 that covers the HM-2140 HF Dual Wattmeter. --------------------------------------------------------------------------------------------------------------------