VK Logger Ham Radio Forum Archive

Been hearing this "squish squosh" QRM pretty often on 80m, around 8AM & 5PM AEST. Very strong, S9+20. Also very broad, on the order of 20kHz wide.

Squish squosh QRM

Any ideas what it could be? Upside is that it doesn't usually go for very long, but when it's happening, it wipes out even the strongest amateur sigs.

73 de Brian

VK2AAF wrote:Been hearing this "squish squosh" QRM pretty often on 80m, around 8AM & 5PM AEST. Very strong, S9+20. Also very broad, on the order of 20kHz wide.

Squish squosh QRM

Any ideas what it could be? Upside is that it doesn't usually go for very long, but when it's happening, it wipes out even the strongest amateur sigs.

73 de Brian

sounds a little like a dialysis pump but obviously not
what time does the hot-water system cycle ?

The hot water system here is a 400L off-peak connected type. Hard to tell when it'll fire up. As it's really only a pair of big stonking resistors which should only connect then disconnect when the water is up to 60C, it doesn't seem to be a likely suspect for this sort of comparatively rapidly fluctuating noise.

If I had to guess, I'd be considering long distance radar, perhaps even JORN.

Hello Brian,
bottom freq for JORN is 5MHz so please do not blame them.

VK2AAF wrote: If I had to guess, I'd be considering long distance radar, perhaps even JORN.

Does it occur during the daytime, i.e., is it likely local? I certainly don't hear it here in QLD, and I scan 80 fairly frequently for Intruder Watch.

It seems to happen for about an hour in the mornings (7-9am local AEST) and occasionally in the mid-afternoon (3-4pm AEST).

Doesn't appear to be a centre frequency to the signal;is seems to be sweeping a range of about 20-30kHz. Would love to get a look at the sig with a spectrum analyser.

VK5PJ wrote:Hello Brian,
bottom freq for JORN is 5MHz so please do not blame them.

OK, thanks- one suspect off the list!