I can talk about the R4B. The blanker works fine on ignition noise, which was what it was mostly designed for but does nothing for the grinding line noise that is much more common. I tested it using a Tektronix pulse generator. It does work but is not like the blankers found in some more modern receivers. The idea of the blanker is to prevent pulse noise like ignition noise from causing the AVC to reduce sensitivity. It also does not affect the sort of noise a conventional noise limiter of the sort found in boatanchor receivers will take out but the usual series valve limiter does not work for CW or SSB. I think there are after market noise removers that work pretty well.
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On 4/11/2021 5:09 AM, David Lipson via groups.io wrote:
Hi
I,ve been trying to use my r4a recently. The pulse noise has been strong, and the blanker does not seem to be helpful. IS the experience of others similar?
73s
David
N9pvf
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Richard Knoppow
1oldlens1@...
WB6KBL
