John K Gotwals wrote:
When I operate on 75 meter SSB with my Orion, my computer beeps and
disconnects/reconnects my USB connected keyboard. Note that I do not have
this problem on 40 meter SSB. My computer is located on the second floor of
a brick house, and one end of my dipole is about 15 feet from my shack.
From comments made by others on this list, I may have to put RF filters on
the cables and wires connected to my computer. I am contemplating the use of
Amidon FT-240-77 ferrite toroids, which have an I.D. of 1.4 inches and cost
$9 each. If I buy in quantities of 10, is there a cheaper source for this
toroid?
Any comments or suggestions on this problem would be appreciated.
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Old thread, but something is exacerbating my problem recently. On 40m CW
the Orion II at full power is now QRM'ing my computer; I had to copy
some traffic by pen and paper this morning because of it.
Two experiments, after wrapping the keyboard cord in three Radio Shack
snap-on ferrite filters: (1) Moving the keyboard about 3' from the
Orion, instead of its usual 1', allows full power keying without
interference, and (2) using a dummy load on the Orion, and then on the
output of the MFJ 993B autotuner, allowed full power without
interference, with the keyboard in its normal place. (Reattaching the
antenna produced the QRM again.)
Any thoughts? I thought perhaps the RFI was from the Orion front panel,
which might explain the moved-keyboard success, and I was surprised to
see the problem disappear with the dummy load.
--John K3GHH
Registered Linux User #291592
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