Topband: "growler" follow-up

[N1BUG]

There was considerable interest in this so I'm posting  a 
follow-up.  Apologies for not replying individually -- more 
than 50 messages on this subject.  ALL greatly appreciated, 
both from fellow sufferers and those with suggestions!  

---

Suggestions:

CATV box.  Try turning it off and see if noise goes away.  A 
U-shaped aluminum cage around the TV, bottom center 
grounded to TV ground helped in at least one case.

CATV leakage was mentioned in several replies.  Try walking 
around with a portable SW receiver tuned to the offending 
noise frequency.  (Q: CATV crud at 1.8 MHz?  Oscillating 
CATV line amplifiers, complex mixing products or ??)

FAX machine, esp. Sharp UX-510.

Navigational / distance measuring buoys (Long Beach Harbor)

Furnace control unit (switching control panel on the furnace 
itself)

Touch lamps

When testing for noise in your own house, don't forget 
battery-operated devices! (smoke detectors, etc.)  Also 
UNPLUG things, don't just turn them off.  Many devices are 
not completely OFF when turned off.

Laptop (whenever plugged in -- suspect something in its 
charging circuit)

Computer power supplies (and power supplies in general). 
CorCom 3VQ1 EMI Filters have cured it for some.

Battery chargers of any type

Broadcast spur

---

It seems a lot of things can "growl" on top band!  Mine 
isn't coming from my own house.  I shut off power to the 
entire house, removed batteries from all devices that use 
them, and powered my receiver with a battery.  No change.  
I disconnected and terminated the CATV feed outside the 
house.  No change (obviously this does not rule out CATV 
leakage however).

I will see if I can borrow a portable SW receiver and go 
hunting.  Meanwhile I hope to be putting up some receive 
antennas soon -- maybe that will help (although this crud 
is very strong).

Again THANKS to all.  Good luck to all who have similar 
problems!

73,
Paul