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Topic Created Posts Views Last Activity
RF noise cancelling at VHF frequencies. Nov 20th 2012, 03:59 2 1,566 on 20/11/12
SWEEP testing a radio from the Mike jack. Jun 4th 2012, 04:57 3 892 on 4/6/12
Power Line Interference. Sep 23rd 2011, 01:07 6 1,968 on 11/5/12

Latest Posts

Topic Author Posted On
cable one digital box for cable tv KD0NMZ 3 weeks, 2 days ago
That's good to hear.
This is why it's best not to launch into all kinds of filters and other things before knowing what the source is.
Good luck.
cable one digital box for cable tv KD0NMZ 3 weeks, 4 days ago
Your not being quite clear about the boxes.
Are there 3 boxes? Is only one affected? etc.
Has another box been tried?
What bands is the box responding to?
The cable boxes are not supposed to respond the your amateur signals especially at such low powers.
Until the interference mechanism is found no filter will help on a wild guess and a hope basis.
More questions; Is the box remote controllable with a hand unit?
If yes, what is the OFF command from the hand unit, as a start to analyze the possible similarity of command signal to your HF signal or harmonics.
Is the box a plastic type cover without any shielding?
This kind of analysis is needed to find a direction to go in; even then it may not be your responsibly for a box that has design issues you cannot overcome with any amount of effort.
Good luck.
Stuff on 3840 W7WHY on 4/7/14
Late to the party but need some opinion.
In contacting our Senators on matters of interference and behavior , I believe their staff and the Senator may not understand the gravity of what is being put forth in a complaint and needs help from some entity that has weight and access to them for consultation on serious matters.
It is difficult enough to get their attention on standard legislation and other matters without going technical on a regulated Hobby they know nothing about..
Is there any format or advice we need to have in pursuing these type of complaints if FCC field office action does not materialize.

Two HF and one VHFwith a triplexer? W1VT on 30/11/13
I know this is an old thread but the subject needs more input.
First there is a multiband antenna on the market now.
Secondly the uses of di or triplexers is not the end all because they do not perform as well as is thought.
Everybody takes them for granted they work without issue.
A check with SWR and power meters on each band between the radio and the plexer will show a significant loss in pass through power and SWR may be high enough to cause transceiver power fold back such that nothing works very well..
Bottom line is not to use them unless you accept the results.
The other answer is to build them custom tuned to each band of use using low loss coaxial designs and adjustable tuned traps.
The ones available are cheap low grade broad band designs for the cost.
Good luck.
Six Meter FM KB5DOH on 31/3/13
What is the reason for doing FM in the SSB portion of the band plan that could not be done in the FM portion above 52 mhz?
Normally vertical polorization is used for net use on this band due to the wide area and close in area of coverge for the purposes of the net..
Expect some time to be challenged when working FM in 50.200 +/- range, especially when the band is open to long distance contacts.
You may do it many times and be legal but expect it may happen.
Let us know.
Good luck.

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