toggle quoted messageShow quoted text
There is a known noise pedestal caused by the cooling fans coming on. This was supposedly solved in production by adding some electrolytics in the DC fan circuitry.
I ran into a similar noise problem from the DC fan in my now discontinued IC-781 cooling kit. I had to use an R/C decoupling circuit to keep the noise from getting back into the radio’s 15 volt supply.
On Jan 12, 2020, at 12:07 PM, Bob McGraw - K4TAX <rmcgraw@...> wrote:
I suggest your find one of the remote SDR's somewhere here in the country and listen to it yourself. Or use a second receiver suitably protected from overload and listen to it yourself.
Make sure the radio ground terminal is bonded back to the station power supply ground. I find that the DC Neg is not adequate to accomplish this and thus allows the radio to float up from ground by the resistance in the DC negative circuit.
On 1/12/2020 10:22 AM, wb6bee wrote:
I have been told by at least two other stations that I have an intermittent 2.5 khz (minimum) noise pedestal on CW. Sounds like key clicks according to them, but a bit different.
Without hearing it myself, it is difficult to describe. The issue is intermittent, they will hear it for a while and it will then be gone.
I am running the K3s. I key with a bug. I have the KPA 1500. The noise is heard with strong signals, although I dropped to barefoot this morning and the listener said he could still tell they were there.
At first, we thought an RFI issue. But, if running barefoot, not likely.